| Genus |
Order |
Reference |
Note |
Nomenclature |
| A | |
| Aa | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aaptos | Hadromerida | Van Soest (2002) | . | ICZN |
| Aaronsonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Abaciasagitta | Aphragmophora | Bieri (1991) | Sagittidae. | ICZN |
| Abarema | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Abatia | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Abbottiella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Abditodentrix | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinitidae. | ICZN |
| Abditomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Abdominea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Abdulmajidia | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Abedinium | Noctilucales | Fensome et al. (1993) | . | ICBN |
| Abeillia | Apodiformes | Clements (2007) | . | ICZN |
| Abelia | Dipsacales | Mabberley (2008) | Caprifoliaceae. | ICBN |
| Abeliophyllum | Lamiales | Mabberley (2008) | Oleaceae. | ICBN |
| Abelspora | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Abeoforma | Ichthyophonida | Marshall & Berbee (2011) | . | ICZN |
| Abeomelomys | Rodentia | Musser & Carleton (2005) | . | ICZN |
| Abies | Pinales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Abietinaria | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Abietinella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Abietinella | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Abildgaardia | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Abiotrophia | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Ablepharus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Abobra | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Abolboda | Poales | Mabberley (2008) | Xyridaceae. | ICBN |
| Aboriella | Rosales | Mabberley (2008) | Urticaceae. | ICBN |
| Abosagitta | Aphragmophora | Kasatkina (2006) | Sagittidae. | ICZN |
| Abrahamia | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Abrawayaomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Abrochtha | Bdelloida | Segers (2002); Segers (2007) | . | ICZN |
| Abrocoma | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Abrodictyum | Hymenophyllales | Christenhusz et al. (2011) | . | ICBN |
| Abroma | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Abronia | Squamata | Vitt & Caldwell (2009) | Anguidae. | ICZN |
| Abronia | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Abrophyllum | Asterales | Mabberley (2008) | Rousseaceae. | ICBN |
| Abroscopus | Passeriformes | Clements (2007) | . | ICZN |
| Abrotanella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Abroteia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Abrothrix | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Abrus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aburria | Galliformes | Clements (2007) | . | ICZN |
| Abuta | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Abutilon | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Abyla | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Abylopsis | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Abyssascidia | Phlebobranchia | Monniot & Monniot (1972); Monniot (2001) | Corellidae. | ICZN |
| Abyssoanthus | Zoanthidea | Reimer et al. (2007) | . | ICZN |
| Abyssocladia | Poecilosclerida | Vacelet (2008) | . | ICZN |
| Abyssopathes | Antipatharia | Opresko (2002) | . | ICZN |
| Abyssotherma | Trochamminida | Kaminski (2000) | Remaneicidae, Trochamminacea. | ICZN |
| Acabaria | Alcyonacea | Bayer (1981) | Melithaeidae. | ICZN |
| Acacia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Acaciella | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Acaena | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Acalle | Haplosclerida | Manconi & Pronzato (2002) | . | ICZN |
| Acalycigorgia | Alcyonacea | Bayer (1981) | Acanthogorgiidae. | ICZN |
| Acalypha | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Acalyptophis | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Acampe | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acamptopappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanella | Alcyonacea | Bayer (1981) | Isididae. | ICZN |
| Acanthacis | Alcyonacea | Bayer (1981) | Plexauridae. | ICZN |
| Acanthagenys | Passeriformes | Clements (2007) | . | ICZN |
| Acanthamoeba | Centramoebida | Rogerson & Patterson (2000); Smirnov et al. (2005); Smirnov et al. (2011) | . | ICZN |
| Acanthancora | Poecilosclerida | Van Soest (2002) | . | ICZN |
| Acanthascus | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Acanthastrea | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Acanthella | Halichondrida | Van Soest et al. (2002) | . | ICZN |
| Acanthella | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Acanthephippium | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acanthidops | Passeriformes | Clements (2007) | . | ICZN |
| Acanthisitta | Passeriformes | Clements (2007) | . | ICZN |
| Acanthixalus | Anura | Vitt & Caldwell (2009) | Hyperoliidae. | ICZN |
| Acanthiza | Passeriformes | Clements (2007) | . | ICZN |
| Acanthocardamum | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Acanthocarpus | Dasypogonales | Mabberley (2008) | Dasypogonaceae. | ICBN |
| Acanthocephaloides | Echinorhynchida | Amin (1985) | . | ICZN |
| Acanthocephalus | Echinorhynchida | Amin (1985) | . | ICZN |
| Acanthocephalus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanthocercus | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Acanthocereus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Acanthochaetetes | Hadromerida | Rützler & Vacelet (2002) | . | ICZN |
| Acanthochelys | Testudinata | Vitt & Caldwell (2009) | Chelidae. | ICZN |
| Acanthochiasma | Holacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthochlamys | Pandanales | Mabberley (2008) | Velloziaceae. | ICBN |
| Acanthochloris | Mischococcales | Ettl (1978); Greuter et al. (1993) | Not Akanthochloris (Greuter et al., 1993). | ICBN |
| Acanthoclada | Halichondrida | Hooper (2002) | . | ICZN |
| Acanthocladium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanthococcus | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Acanthocoleus | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acanthocolla | Holacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthocorbis | Acanthoecida | Leadbeater & Thomsen (2000) | . | ICZN |
| Acanthocorys | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Acanthocyrtha | Holacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthocystis | Acanthocystida | Mikrjukov et al. (2000); Cavalier-Smith & von der Heyden (2007); Yabuki et al. (2012) | Acanthocystidae. | ICZN |
| Acanthodactylus | Squamata | Vitt & Caldwell (2009) | Lacertidae. | ICZN |
| Acanthodasys | Macrodasyida | Hummon & Todaro (2010) | . | ICZN |
| Acanthodendrilla | Dendroceratida | Bergquist & Cook (2002) | . | ICZN |
| Acanthodesmia | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Acanthodesmos | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanthodinium | Gonyaulacales | Fensome et al. (1993) | . | ICBN |
| Acanthodiophrya | Astomatida | Lynn (2008) | . | ICZN |
| Acanthoeca | Acanthoecida | Leadbeater & Thomsen (2000) | . | ICZN |
| Acanthoecopsis | Acanthoecida | Hara & Takahashi (1984); Cavalier-Smith & Chao (2003); Nitsche et al. (2011) | Junior synonym of Polyoeca. | ICZN |
| Acanthoepimeritus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acanthogilia | Ericales | Mabberley (2008) | Polemoniaceae. | ICBN |
| Acanthogonyaulax | Gonyaulacales | Fensome et al. (1993) | . | ICBN |
| Acanthogorgia | Alcyonacea | Bayer (1981) | Acanthogorgiidae. | ICZN |
| Acanthogregarina | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acanthogyrus | Gyracanthocephala | Amin (1985) | . | ICZN |
| Acanthoica | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Rhabdosphaeraceae. | ICBN |
| Acanthokara | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Acantholejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acantholepis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acantholimon | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Acantholippia | Lamiales | Mabberley (2008) | Verbenaceae. | ICBN |
| Acantholithium | Symphyacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthometra | Arthracanthida | Febvre et al. (2000) | . | ICZN |
| Acanthomintha | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Acanthonema | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Acanthopale | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Acanthopathes | Antipatharia | Opresko (2004) | . | ICZN |
| Acanthopeltis | Gelidiales | Schneider & Wynne (2007) | . | ICBN |
| Acanthophis | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Acanthophoenix | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Acanthophora | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Acanthophrya | Astomatida | Lynn (2008) | . | ICZN |
| Acanthophyllia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Acanthophyllum | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Acanthoplegma | Holacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthopleuribacter | Acanthopleuribacterales | Fukunaga et al. (2008) | . | ICNB |
| Acanthopolymastia | Hadromerida | Boury-Esnault (2002) | . | ICZN |
| Acanthopriapulus | Priapulomorpha | Adrianov & Malakhov (1996) | . | ICZN |
| Acanthopsis | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Acanthoptilum | Pennatulacea | Williams (1995) | . | ICZN |
| Acanthorhabdus | Poecilosclerida | Hooper (2002) | . | ICZN |
| Acanthorhynchus | Passeriformes | Clements (2007) | . | ICZN |
| Acanthornis | Passeriformes | Clements (2007) | . | ICZN |
| Acanthorrhinum | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Acanthorrhynchium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Acanthosaura | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Acanthoscyphus | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Acanthosicyos | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Acanthospermum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanthosphaera | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Acanthospira | Holacanthida | Febvre et al. (2000) | . | ICZN |
| Acanthospora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acanthosporidium | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acanthostachys | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Acanthostaurus | Arthracanthida | Febvre et al. (2000) | . | ICZN |
| Acanthostomella | Tintinnida | Lynn (2008) | . | ICZN |
| Acanthostrongylophora | Haplosclerida | Desqueyroux-Faúndez & Valentine (2002) | . | ICZN |
| Acanthostyles | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acanthosyris | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Acanthotetilla | Spirophorida | Van Soest & Rützler (2002) | . | ICZN |
| Acanthothamnus | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Acanthotriaena | Astrophorida | Maldonado (2002) | . | ICZN |
| Acanthura | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Acanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Acareosperma | Vitales | Mabberley (2008) | Vitaceae. | ICBN |
| Acaricomes | Micrococcales | Pukall et al. (2006); Ludwig et al. (2012) | . | ICNB |
| Acarnus | Poecilosclerida | Hooper (2002) | . | ICZN |
| Acarogregarina | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acarpha | Asterales | Mabberley (2008) | Calyceraceae. | ICBN |
| Acaryophrya | Haptorida | Lynn (2008) | . | ICZN |
| Acaulimalva | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Acaulis | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Acauloides | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Acaulon | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Acca | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Accara | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Accipiter | Falconiformes | Clements (2007) | . | ICZN |
| Acentra | Malpighiales | Mabberley (2008) | Violaceae. | ICBN |
| Acer | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Aceratium | Oxalidales | Mabberley (2008) | Elaeocarpaceae. | ICBN |
| Aceratorchis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acerodon | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Aceros | Coraciiformes | Clements (2007) | . | ICZN |
| Acervulina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Acervulinidae. | ICZN |
| Acetanaerobacterium | Clostridiales | Chen & Dong (2004) | . | ICNB |
| Acetitomaculum | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Acetivibrio | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Acetoanaerobium | Clostridiales | Garrity et al. (2005); Ludwig et al. (2009) | . | ICNB |
| Acetobacter | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Acetobacterium | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Acetofilamentum | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Acetogenium | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Acetohalobium | Halanaerobiales | Garrity et al. (2005) | . | ICNB |
| Acetomicrobium | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Acetonema | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Acetothermus | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Achalinus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Acharagma | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Acharia | Malpighiales | Mabberley (2008) | Achariaceae. | ICBN |
| Achatocarpus | Caryophyllales | Mabberley (2008) | Achatocarpaceae. | ICBN |
| Acheliderma | Poecilosclerida | Hooper (2002) | . | ICZN |
| Achemon | Cristamonadida | Cepicka et al. (2010) | . | ICZN |
| Achetaria | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Achillea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achimenes | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Achlaena | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Achlya | Saprolegniales | Dick (2001); Kirk et al. (2008) | Saprolegniaceae. | ICBN |
| Achlyphila | Poales | Mabberley (2008) | Xyridaceae. | ICBN |
| Achlys | Ranunculales | Mabberley (2008) | Berberidaceae. | ICBN |
| Achnatherum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Achnophora | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achnopogon | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achoerus | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Acholeplasma | Acholeplasmatales | Garrity et al. (2005) | . | ICNB |
| Achoronemertes | Cratenemertea | Crandall & Gibson (1998) | . | ICZN |
| Achradina | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Achramorpha | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Achromatium | Thiotrichales | Garrity et al. (2005) | . | ICNB |
| Achromobacter | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Achrophyllum | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Achyrachaena | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achyranthes | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Achyrocalyx | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Achyrocline | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achyronychia | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Achyropappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Achyropsis | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Achyrospermum | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Aciachne | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acianthus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acicarpha | Asterales | Mabberley (2008) | Calyceraceae. | ICBN |
| Aciculites | | Pisera & Lévi (2002) | Domain Eucarya - Kingdom Animalia - Phylum Porifera - Class Demospongiae (lithistids) Scleritodermidae. | ICZN |
| Acidaminobacter | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Acidaminococcus | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Acidianus | Sulfolobales | Garrity et al. (2005) | . | ICNB |
| Acidicaldus | Rhodospirillales | Johnson et al. (2006) | . | ICNB |
| Acidicapsa | Acidobacteriales | Kulichevskaya et al. (2012) | . | ICNB |
| Acidiferrobacter | Chromatiales | Hallberg et al. (2011) | . | ICNB |
| Acidilobus | Acidilobales | Garrity et al. (2005); Prokofeva et al. (2009) | . | ICNB |
| Acidimicrobium | Acidimicrobiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Acidiphilium | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Acidiplasma | Picrophilales | Golyshina et al. (2009) | . | ICNB |
| Acidisoma | Rhodospirillales | Belova et al. (2009) | . | ICNB |
| Acidisphaera | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Aciditerrimonas | Acidimicrobiales | Itoh et al. (2011); Ludwig et al. (2012) | . | ICNB |
| Acidithiobacillus | Acidithiobacillales | Garrity et al. (2005) | . | ICNB |
| Acidobacterium | Acidobacteriales | Garrity et al. (2005); Fukunaga et al. (2008) | . | ICNB |
| Acidocella | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Acidocroton | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Acidodontium | Bryales | Goffinet et al. (2009) | . | ICBN |
| Acidomonas | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Acidonia | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Acidosasa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acidothermus | Frankiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Acidoton | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Acidovorax | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Acineria | Pleurostomatida | Lynn (2008) | . | ICZN |
| Acineta | Endogenida | Lynn (2008) | . | ICZN |
| Acineta | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acinetactis | Pansomonadida | Bass et al. (2009); Yabuki et al. (2012) | . | ICZN |
| Acinetides | Endogenida | Lynn (2008) | . | ICZN |
| Acinetobacter | Pseudomonadales | Garrity et al. (2005) | . | ICNB |
| Acinetopsis | Endogenida | Lynn (2008) | . | ICZN |
| Acinonyx | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Acioa | Malpighiales | Mabberley (2008) | Chrysobalanaceae. | ICBN |
| Aciotis | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Aciphylla | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Acis | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Acisanthera | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Ackama | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Ackermania | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acleisanthes | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Acmadenia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Acmanthera | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Acmella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acmispon | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Acmopyle | Araucariales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Acnistus | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Acoelocalyx | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Acoelophthirius | Endogenida | Lynn (2008) | . | ICZN |
| Acoelorrhaphe | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Acokanthera | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Acomastylis | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Acomis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aconaemys | Rodentia | McKenna & Bell (1997); Woods & Kilpatrick (2005) | Later synonym of Pithanotomys. | ICZN |
| Aconitum | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Aconthaspis | Arthracanthida | Febvre et al. (2000) | . | ICZN |
| Acontiactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Acontias | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Acontiophorum | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Acontophiops | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Acorus | Acorales | Mabberley (2008) | Acoraceae. | ICBN |
| Acosmium | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Acostaea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acostata | Lituolida | Kaminski (2000) | Cuneatinae. | ICZN |
| Acostia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acostina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Reussellidae. | ICZN |
| Acourtia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acrachne | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acradenia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Acramoeba | Varipodida | Smirnov et al. (2008) | . | ICZN |
| Acranthera | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Acrantophis | Squamata | Vitt & Caldwell (2009) | Serpentes. Boidae. | ICZN |
| Acrasis | Acrasida | Kirk et al. (2008) | . | ICZN |
| Acraspedanthus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Acrhelia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Acridocarpus | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Acridotheres | Passeriformes | Clements (2007) | . | ICZN |
| Acriopsis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acris | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Acrisione | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acritochaete | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acritodon | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Acritopappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acrobates | Australidelphia | McKenna & Bell (1997) | . | ICZN |
| Acrobatornis | Passeriformes | Clements (2007) | . | ICZN |
| Acrobolbus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acrobotrys | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Acrobotrys | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Acrocarpospora | Streptosporangiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Acrocarpus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Acrocephalus | Passeriformes | Clements (2007) | . | ICZN |
| Acroceras | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Acrochaetium | Acrochaetiales | Schneider & Wynne (2007) | . | ICBN |
| Acrochila | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acrochordus | Squamata | Vitt & Caldwell (2009) | Serpentes. Acrochordidae. | ICZN |
| Acrocladium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Acrocoelus | Acrocoelida | Cavalier-Smith & Chao (2004) | . | ICZN |
| Acrocomia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Acrocoryne | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Acrocystis | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Acrodiscus | Cryptonemiales | Silva (2002); Schneider & Wynne (2007) | . | ICBN |
| Acrodon | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Acroglochin | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Acrolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acrolophia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acrolophozia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acromastigum | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acromitoides | Rhizostomeae | Kramp (1961) | . | ICZN |
| Acromitus | Rhizostomeae | Kramp (1961) | . | ICZN |
| Acronema | Anoecales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Acronema | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Acronychia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Acrophorus | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Acrophyllum | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Acrophytum | Alcyonacea | Bayer (1981) | Alcyoniidae. | ICZN |
| Acropisthium | Haptorida | Lynn (2008) | . | ICZN |
| Acropogon | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Acropora | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Acroporium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Acropternis | Passeriformes | Clements (2007) | . | ICZN |
| Acroptilon | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Acrorchis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Acrorumohra | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Acrosanthes | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Acroschisma | Andreaeales | Goffinet et al. (2009) | . | ICBN |
| Acroscyphella | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Acrosorium | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Acrosorus | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Acrosphaera | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Acrossota | Alcyonacea | Alderslade & McFadden (2007) | Acrossotidae. | ICZN |
| Acrostichum | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Acrosymphyton | Acrosymphytales | Schneider & Wynne (2007) | . | ICBN |
| Acrothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Acrothamniopsis | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Acrotome | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Acrotrema | Dilleniales | Mabberley (2008) | Dilleniaceae. | ICBN |
| Acrotriche | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Acrotylus | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Acrozoanthus | Zoanthidea | Sinniger et al. (2005) | . | ICZN |
| Acryllium | Galliformes | Clements (2007) | . | ICZN |
| Acrymia | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Acryptolaria | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Acsmithia | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Actaea | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Actenoides | Coraciiformes | Clements (2007) | . | ICZN |
| Acteonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Actephila | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Acthelmis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actibacter | Flavobacteriales | Kim et al. (2008) | . | ICNB |
| Actibacterium | Rhodobacterales | Lucena et al. (2012) | . | ICNB |
| Actinanthella | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Actinarctus | Arthrotardigrada | Kinchin (1994) | . | ICZN |
| Actinastrum | Chlorellales | Luo et al. (2009) | Chlorella clade in Chlorellaceae. | ICBN |
| Actinauge | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinaurispora | Micromonosporales | Thawai et al. (2010); Ludwig et al. (2012) | Micromonosporaceae. | ICNB |
| Actinecta | Actiniaria | Fautin et al. (2007) | Replacement name for Mynias, but not currently considered valid. | ICZN |
| Actinellipsoidion | Mischococcales | Ettl (1978) | . | ICBN |
| Actineria | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinernus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinichona | Cryptogemmida | Lynn (2008) | . | ICZN |
| Actinidia | Ericales | Mabberley (2008) | Actinidiaceae. | ICBN |
| Actiniopteris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Actiniscus | Gymnodiniales | Dodge & Lee (2000) | . | ICBN |
| Actinoallomurus | Streptosporangiales | Tamura et al. (2009); Ludwig et al. (2012) | . | ICNB |
| Actinoalloteichus | Pseudonocardiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinobacillus | Pasteurellales | Garrity et al. (2005) | . | ICNB |
| Actinobaculum | Actinomycetales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinobispora | Pseudonocardiales | Garrity et al. (2005); Huang & Goodfellow (2012) | Later synonym of Pseudonocardia. | ICNB |
| Actinobole | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Actinobolina | Haptorida | Lynn (2008) | . | ICZN |
| Actinocarya | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Actinocatenispora | Micromonosporales | Thawai et al. (2006); Ludwig et al. (2012) | . | ICNB |
| Actinocephalus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Actinocephalus | Poales | Mabberley (2008) | Eriocaulaceae. | ICBN |
| Actinocheita | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Actinocladum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Actinocorallia | Streptosporangiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinocoryne | Gymnosphaerida | Mikrjukov et al. (2000); Adl et al. (2005) | Gymnosphaeridae. | ICZN |
| Actinocyathula | Exogenida | Lynn (2008) | . | ICZN |
| Actinodactylus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinodaphne | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Actinodendron | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinodinium | | Fensome et al. (1993); Skovgaard et al. (2007) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. Former Blastodiniales. | ICBN |
| Actinodiscus | Corallimorpharia | Fautin et al. (2007) | . | ICZN |
| Actinodium | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Actinodontium | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Actinodura | Passeriformes | Clements (2007) | . | ICZN |
| Actinokentia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Actinokineospora | Pseudonocardiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinolema | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Actinolophus | Gymnosphaerida | Mikrjukov et al. (2000); Adl et al. (2005) | Other Heliozoa. | ICZN |
| Actinomadura | Streptosporangiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinomma | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Actinomonas | Pedinellales | Moestrup (2000); Sekiguchi et al. (2003) | . | ICBN |
| Actinomyces | Actinomycetales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinomycetospora | Pseudonocardiales | Jiang et al. (2008); Ludwig et al. (2012) | . | ICNB |
| Actinophrys | Actinophryales | Mikrjukov & Patterson (2001) | . | ICZN |
| Actinophytocola | Pseudonocardiales | Indananda et al. (2010); Ludwig et al. (2012) | Pseudonocardiaceae. | ICNB |
| Actinoplanes | Micromonosporales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinopolymorpha | Propionibacteriales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinopolyspora | Actinopolysporales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinoporus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinoposthia | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Actinopsis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinoptilum | Pennatulacea | Williams (1995) | . | ICZN |
| Actinorhabdos | Haptorida | Lynn (2008) | . | ICZN |
| Actinorhytis | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Actinoschoenus | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Actinoscirpus | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Actinoscyphia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinosphaerium | Actinophryales | Mikrjukov & Patterson (2001) | . | ICZN |
| Actinospica | Catenulisporales | Cavaletti et al. (2006); Ludwig et al. (2012) | . | ICNB |
| Actinostachys | Schizaeales | Christenhusz et al. (2011) | . | ICBN |
| Actinostella | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinostemma | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Actinostemon | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Actinostephanus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinostola | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinostrobus | Cupressales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Actinosynnema | Pseudonocardiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Actinotaenium | Desmidiales | Gontcharov (2008) | . | ICBN |
| Actinotalea | Micrococcales | Yi et al. (2007); Ludwig et al. (2012) | . | ICNB |
| Actinothoe | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Actinothuidium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Actinotricha | Sporadotrichida | Lynn (2008) | Later synonym of Oxytricha?. | ICZN |
| Actinotrichia | Nemaliales | Schneider & Wynne (2007) | . | ICBN |
| Actinotus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Actissa | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Actites | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Actitis | Charadriiformes | Clements (2007) | . | ICZN |
| Actophilornis | Charadriiformes | Clements (2007) | . | ICZN |
| Actuariola | Neobodonida | Stoeck et al. (2005) | . | ICZN |
| Aculeola | Squaliformes | Nelson (2006) | . | ICZN |
| Acunaeanthus | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Acupeina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Acupeinidae. | ICZN |
| Acuta | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acutispora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Acutogordius | Gordioidea | Schmidt-Rhaesa (2002); Poinar Jr. (2008) | . | ICZN |
| Acutotyphlops | Squamata | Vitt & Caldwell (2009) | Serpentes. Typhlopidae. | ICZN |
| Acyclus | Collothecaceae | Segers (2002); Segers (2007) | . | ICZN |
| Acystopteris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Acytostelium | Dictyosteliales | Hagiwara (1989) | . | ICBN |
| Ada | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Adagnesia | Phlebobranchia | Monniot & Monniot (1972); Monniot (2001) | Agneziidae. | ICZN |
| Adamsia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Adamsiella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Adansonia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Addax | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Adelanthus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Adelea | Eucoccidiorida | Perkins et al. (2000) | . | ICZN |
| Adelia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Adelina | Eucoccidiorida | Perkins et al. (2000); Özdikmen (2009) | Junior homonym. Substituted by Obvallatus. | ICZN |
| Adelobotrys | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Adelogorgia | Alcyonacea | Bayer (1981) | Gorgoniidae. | ICZN |
| Adelomyia | Apodiformes | Clements (2007) | . | ICZN |
| Adelophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Adelophryne | Anura | Vitt & Caldwell (2009) | Brachycephalidae. | ICZN |
| Adelophycus | Nemastomatales | Schneider & Wynne (2007) | . | ICBN |
| Adelopora | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Adelosina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Spiroloculinidae. | ICZN |
| Adelostemma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Adelostigma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adelothecium | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Adelotus | Anura | Vitt & Caldwell (2009) | Limnodynastidae. | ICZN |
| Adelphamoeba | Schizopyrenida | De Jonckheere et al. (1997); Patterson et al. (2000) | Junior synonym of Tetramitus. | ICZN |
| Adelphicos | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Adelphobates | Anura | Vitt & Caldwell (2009) | Dendrobatidae. | ICZN |
| Adelphocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Adenandra | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Adenanthellum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenanthera | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adenanthos | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Adenarake | Malpighiales | Mabberley (2008) | Ochnaceae. | ICBN |
| Adenaria | Myrtales | Mabberley (2008) | Lythraceae. | ICBN |
| Adenia | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Adenium | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Adenoa | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Adenocalymma | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Adenocarpus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adenocauda | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Adenocaulon | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenochilus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Adenocline | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Adenocritonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenoderris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Adenodolichos | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adenoglossa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenogramma | Caryophyllales | Mabberley (2008) | Molluginaceae. | ICBN |
| Adenoides | | Fensome et al. (1993) | Domain Eucarya - Phylum Dinozoa - Class Dinophyceae - Subclass Peridiniphycidae. | ICBN |
| Adenolobus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adenomus | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Adenoncos | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Adenoon | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenopea | Acoela | Faubel & Noreña (2001) | . | ICZN |
| Adenopeltis | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Adenophaedra | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Adenophora | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Adenophorus | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Adenophyllum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenopodia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adenorandia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Adenorhagas | Heteronemertea | Gibson (1995) | . | ICZN |
| Adenorhinos | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Adenosciadium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Adenosma | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Adenostemma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenostoma | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Adenostyles | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adenothamnus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Adercotryma | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammosphaeroidinidae. | ICZN |
| Adesmia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Adhaeribacter | Cytophagales | Rickard et al. (2005); Ludwig et al. (2011) | . | ICNB |
| Adhesisagitta | Aphragmophora | Bieri (1991); Kassatkina (2010) | Junior synonym of Ferosagitta. | ICZN |
| Adiantopsis | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Adiantum | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Adina | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Adinandra | Ericales | Mabberley (2008) | Pentaphylacaceae. | ICBN |
| Adinauclea | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Adineta | Bdelloida | Segers (2002); Segers (2007) | . | ICZN |
| Adinimonas | Desmocapsales | Fensome et al. (1993) | . | ICBN |
| Adiscanthus | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Adlercreutzia | Coriobacteriales | Maruo et al. (2008); Ludwig et al. (2012) | . | ICNB |
| Adlerocystis | | Kirk et al. (2008) | Domain Eucarya - Kingdom Straminipila. | ICBN |
| Adlumia | Ranunculales | Mabberley (2008) | Papaveraceae. | ICBN |
| Adolfus | Squamata | Vitt & Caldwell (2009) | Lacertidae. | ICZN |
| Adolphia | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Adonidia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Adonis | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Adorybiotus | Parachela | Kinchin (1994) | . | ICZN |
| Adoxa | Dipsacales | Mabberley (2008) | Adoxaceae. | ICBN |
| Adrastaea | Dilleniales | Mabberley (2008) | Dilleniaceae. | ICBN |
| Adreus | Hadromerida | Hooper (2002) | . | ICZN |
| Adriamonas | Pseudodendromonadales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Adriana | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Adrianema | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Adromischus | Saxifragales | Mabberley (2008) | Crassulaceae. | ICBN |
| Adrorhizon | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Advenella | Burkholderiales | Coeye et al. (2005) | . | ICNB |
| Aechmalotus | Acoela | Dörjes (1968) | . | ICZN |
| Aechmea | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Aechmophorus | Podicipediformes | Clements (2007) | . | ICZN |
| Aedesia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aegialitis | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Aegialonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Aegiceras | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Aegilops | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aegina | Narcomedusae | Bouillon et al. (2006) | . | ICZN |
| Aeginetia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Aeginodiscus | Narcomedusae | Bouillon et al. (2006) | . | ICZN |
| Aeginopsis | Narcomedusae | Bouillon et al. (2006) | . | ICZN |
| Aeginura | Narcomedusae | Bouillon et al. (2006) | . | ICZN |
| Aegiphila | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Aegithalos | Passeriformes | Clements (2007) | . | ICZN |
| Aegithina | Passeriformes | Clements (2007) | . | ICZN |
| Aegle | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Aeglopsis | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Aegokeras | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aegolius | Strigiformes | Clements (2007) | . | ICZN |
| Aegopodium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aegopordon | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aegotheles | Caprimulgiformes | Clements (2007) | . | ICZN |
| Aegypius | Falconiformes | Clements (2007) | . | ICZN |
| Aegyptianella | Rickettsiales | Garrity et al. (2005) | . | ICNB |
| Aegyria | Dysteriida | Chen et al. (2012) | . | ICZN |
| Aegyriana | Dysteriida | Lynn (2008) | . | ICZN |
| Aeluroglena | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Aeluropus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aeluroscalabotes | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Aenhenrya | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aenictophyton | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aenigmanemertes | Eumonostilifera | Chernyshev (2005); Kajihara et al. (2008) | Poseidonemertidae. | ICZN |
| Aenigmatolimnas | Gruiformes | Clements (2007) | . | ICZN |
| Aenigmopteris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Aeodes | Cryptonemiales | Silva (2002); Schneider & Wynne (2007) | . | ICBN |
| Aeollanthus | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Aeonium | Saxifragales | Mabberley (2008) | Crassulaceae. | ICBN |
| Aepeomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aepyceros | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Aepypodius | Galliformes | Clements (2007) | . | ICZN |
| Aepyprymnus | Australidelphia | McKenna & Bell (1997) | . | ICZN |
| Aequatorium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aequorea | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Aequorivita | Flavobacteriales | Garrity et al. (2005) | . | ICNB |
| Aerangis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aeranthes | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aeretes | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aeribacillus | Bacillales | Miñana-Galbis et al. (2010) | . | ICNB |
| Aerides | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aeriscardovia | Bifidobacteriales | Simpson et al. (2004); Ludwig et al. (2012) | . | ICNB |
| Aerobryidium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aerobryopsis | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aerobryum | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aerococcus | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Aerodramus | Apodiformes | Clements (2007) | . | ICZN |
| Aerolindigia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aeromicrobium | Propionibacteriales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Aeromonas | Aeromonadales | Garrity et al. (2005) | . | ICNB |
| Aeromys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aeronautes | Apodiformes | Clements (2007) | . | ICZN |
| Aeronema | Tribonematales | Ettl (1978); Silva (1979) | Not "Aeronemum". | ICBN |
| Aeronemum | Tribonematales | Ettl (1978); Silva (1979) | Incorrect spelling of "Aeronema". | ICBN |
| Aeropyrum | Desulfurococcales | Garrity et al. (2005) | . | ICNB |
| Aerva | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Aeschynanthus | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Aeschynomene | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aesculus | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Aestuariibacter | Alteromonadales | Yi et al. (2004) | . | ICNB |
| Aestuariicola | Flavobacteriales | Yoon et al. (2008) | . | ICNB |
| Aestuariimicrobium | Propionibacteriales | Jung et al. (2007); Ludwig et al. (2012) | . | ICNB |
| Aetanthus | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Aethalops | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Aetheolineus | Heteronemertea | Gibson (1995) | . | ICZN |
| Aetheolirion | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Aetheorhynchus | Heteronemertea | Gibson (1995) | . | ICZN |
| Aethephyllum | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Aethia | Charadriiformes | Clements (2007) | . | ICZN |
| Aethionema | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aethomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aethopyga | Passeriformes | Clements (2007) | . | ICZN |
| Aethrikos | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Aethusa | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aetobatus | Myliobatiformes | Nelson (2006) | . | ICZN |
| Aetomylaeus | Myliobatiformes | Nelson (2006) | . | ICZN |
| Aetoplatea | Myliobatiformes | Nelson (2006) | . | ICZN |
| Aetoxylon | Malvales | Mabberley (2008) | Thymelaeaceae. | ICBN |
| Aextoxicon | Berberidopsidales | Mabberley (2008) | Aextoxicaceae. | ICBN |
| Affinetrina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Afgekia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Afifella | Rhizobiales | Urdiain et al. (2008) | . | ICNB |
| Afipia | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Afraegle | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Aframmi | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aframomum | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Africanemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Afrixalus | Anura | Vitt & Caldwell (2009) | Hyperoliidae. | ICZN |
| Afroablepharus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Afroamphisiella | Stichotrichida | Lynn (2008) | . | ICZN |
| Afrocalathea | Zingiberales | Mabberley (2008) | Marantaceae. | ICBN |
| Afrocarpus | Araucariales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Afrocarum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Afroedura | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Afrofittonia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Afrogecko | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Afroguatteria | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Afrokeronopsis | Sporadotrichida | Foissner et al. (2010) | . | ICZN |
| Afrolicania | Malpighiales | Mabberley (2008) | Chrysobalanaceae. | ICBN |
| Afroligusticum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Afrolimon | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Afronatrix | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Afronta | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Afropavo | Galliformes | Clements (2007) | . | ICZN |
| Afrophrya | Sporadotrichida | Lynn (2008) | . | ICZN |
| Afrosison | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Afrostyrax | Oxalidales | Mabberley (2008) | Huaceae. | ICBN |
| Afrothismia | Dioscoreales | Mabberley (2008) | Thismiaceae. | ICBN |
| Afrothrix | Urostylida | Lynn (2008) | . | ICZN |
| Afrotrewia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Afrotrichloris | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Afrotrilepis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Afrotysonia | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Afrovivella | Saxifragales | Mabberley (2008) | Crassulaceae. | ICBN |
| Afzelia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Agalinis | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Agalma | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Agalmyla | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Agalychnis | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Agama | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Agamia | Ciconiiformes | Clements (2007) | . | ICZN |
| Agamodon | Squamata | Vitt & Caldwell (2009) | Trogonophidae. | ICZN |
| Agamura | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Aganisia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aganonerion | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aganope | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aganosma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Agapanthus | Asparagales | Mabberley (2008) | Agapanthaceae. | ICBN |
| Agapetes | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Agapornis | Psittaciformes | Clements (2007) | . | ICZN |
| Agardhiella | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Agardhinula | Rhodymeniales | Schneider & Wynne (2007) | . | ICBN |
| Agarella | Bivalvulida | Lom & Dyková (2006) | . | ICZN |
| Agaricia | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Agaricicola | | Chu et al. (2010) | Domain Bacteria - Phylum Proteobacteria - Class Alphaproteobacteria. Closely related to Rhodobacterales. | ICNB |
| Agaricoides | Alcyonacea | Bayer (1981) | Nidaliidae. | ICZN |
| Agarista | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Agarivorans | Alteromonadales | Kurahashi & Yokota (2004) | . | ICNB |
| Agastache | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Agastachys | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Agasyllis | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Agatea | Malpighiales | Mabberley (2008) | Violaceae. | ICBN |
| Agathis | Araucariales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Agathisanthemum | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Agathosma | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Agave | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Agdestis | Caryophyllales | Mabberley (2008) | Phytolaccaceae. | ICBN |
| Agelaea | Oxalidales | Mabberley (2008) | Connaraceae. | ICBN |
| Agelaioides | Passeriformes | Clements (2007) | . | ICZN |
| Agelaius | Passeriformes | Clements (2007) | . | ICZN |
| Agelanthus | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Agelas | Agelasida | Van Soest (2002) | . | ICZN |
| Agelastes | Galliformes | Clements (2007) | . | ICZN |
| Agelasticus | Passeriformes | Clements (2007) | . | ICZN |
| Agenium | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ageratella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ageratina | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ageratinastrum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ageratum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aggerostramen | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Telamminidae. | ICZN |
| Agglomerata | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Agglutinaria | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Agglutinella | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Aggregata | Eucoccidiorida | Perkins et al. (2000) | . | ICZN |
| Aggregatibacter | Pasteurellales | Nørskov-Lauritsen & Kilian (2006) | . | ICNB |
| Agitata | Pansomonadida | Bass et al. (2009); Howe et al. (2011) | . | ICZN |
| Agitococcus | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Agkistrodon | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Aglaeactis | Apodiformes | Clements (2007) | . | ICZN |
| Aglaia | Sapindales | Mabberley (2008) | Meliaceae. | ICBN |
| Aglaiocercus | Apodiformes | Clements (2007) | . | ICZN |
| Aglantha | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Aglaodorum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Aglaomorpha | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Aglaonema | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Aglaophenia | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Aglaothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Aglaura | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Aglauropsis | Limnomedusae | Bouillon et al. (2006) | . | ICZN |
| Aglossorrhyncha | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aglyptodactylus | Anura | Vitt & Caldwell (2009) | Mantellidae. | ICZN |
| Agmasoma | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Agnathiella | Bursovaginoidea | Sørensen (2002) | . | ICZN |
| Agnathodysteria | Dysteriida | Lynn (2008) | . | ICZN |
| Agnesia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Agnesiopsis | Phlebobranchia | Monniot & Monniot (1972); Monniot (2001) | Junior synonym of Corynascidia. Agnesiopsis translucida is currently Corynascidia translucida. | ICZN |
| Agnezia | Phlebobranchia | Monniot & Monniot (1972); Kott (1998); Monniot (2001) | Agneziidae. Replacement name for Agnesia. | ICZN |
| Agnorhiza | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Agolohymena | Tetrahymenida | Bourland & Strüder-Kypke (2010) | . | ICZN |
| Agonandra | Santalales | Mabberley (2008) | Opiliaceae. | ICBN |
| Agonis | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Agoseris | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Agouti | Rodentia | McKenna & Bell (1997); Woods & Kilpatrick (2005) | Later synonym of Cuniculus. Cuniculus is conserved. | ICZN |
| Agreia | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Agrianthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Agrimonia | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Agriophyllum | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Agriornis | Passeriformes | Clements (2007) | . | ICZN |
| Agrippina | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Agrobacterium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Agrocharis | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Agrococcus | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Agromonas | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Agromyces | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Agropyron | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Agropyropsis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Agrosphaera | | Fensome et al. (1993) | Domain Eucarya - Phylum Dinozoa - Superclass Dinokaryota. | ICBN |
| Agrostemma | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Agrostis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Agrostistachys | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Agrostocrinum | Asparagales | Mabberley (2008) | Hemerocallidaceae. | ICBN |
| Agrostophyllum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aguiaria | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Agyrtria | Apodiformes | Clements (2007) | . | ICZN |
| Ahaetulla | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Ahernia | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Ahnfeltia | Ahnfeltiales | Schneider & Wynne (2007) | . | ICBN |
| Ahnfeltiopsis | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Ahrensia | Rhizobiales | Garrity et al. (2005); Lee et al. (2005) | . | ICNB |
| Aichryson | Saxifragales | Mabberley (2008) | Crassulaceae. | ICBN |
| Aidanosagitta | Aphragmophora | Bieri (1991) | Sagittidae. | ICZN |
| Aidia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aidingimonas | Oceanospirillales | Wang et al. (2009) | . | ICNB |
| Aidiopsis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aidomene | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aikinetocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Ailanthus | Sapindales | Mabberley (2008) | Simaroubaceae. | ICBN |
| Ailuroedus | Passeriformes | Clements (2007) | . | ICZN |
| Ailuronyx | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Ailuropoda | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Ailurops | Diprotodontia | Groves (2005) | . | ICZN |
| Ailurus | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Aimophila | Passeriformes | Clements (2007) | . | ICZN |
| Ainea | Asparagales | Mabberley (2008) | Iridaceae. | ICBN |
| Ainigmaptilon | Alcyonacea | Bayer (1981) | Primnoidae. | ICZN |
| Ainsliaea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ainsworthia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aiocolax | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Aiolochroia | Verongida | Bergquist & Cook (2002) | . | ICZN |
| Aiouea | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Aiphanes | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Aiptasia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Aiptasiogeton | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Aiptasiomorpha | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Aipysurus | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Aira | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Airopsis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Airosperma | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Airyantha | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aistopetalum | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Aitchisoniella | Marchantiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Aix | Anseriformes | Clements (2007) | . | ICZN |
| Aizoanthemum | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Aizoon | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Ajania | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ajaniopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ajuga | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Ajugoides | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Aka | Haplosclerida | Desqueyroux-Faúndez & Valentine (2002) | . | ICZN |
| Akalaphycus | Nemaliales | Schneider & Wynne (2007) | . | ICBN |
| Akania | Brassicales | Mabberley (2008) | Akaniaceae. | ICBN |
| Akashiwo | Gymnodiniales | Daugbjerg et al. (2000) | . | ICBN |
| Akeassia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Akebia | Ranunculales | Mabberley (2008) | Lardizabalaceae. | ICBN |
| Akidodes | Astomatida | Lynn (2008) | . | ICZN |
| Akkermansia | Verrucomicrobiales | Derrien et al. (2004) | . | ICNB |
| Akodon | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Akrosida | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Akrostomum | Cratenemertea | Gibson (1995); Crandall & Gibson (1998); Kajihara et al. (2008) | Valid name against Valdivianemertes. | ICZN |
| Akschindlium | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aktinothele | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Alabamina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Alabaminidae. | ICZN |
| Alabaminella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Eponididae. | ICZN |
| Alabaminoides | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Pseudoparrellidae. | ICZN |
| Alacrinella | Ichthyophonida | Cafaro (2005); Kirk et al. (2008) | Eccrinales in mycology. | ICZN |
| Alaemon | Passeriformes | Clements (2007) | . | ICZN |
| Alafia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Alajja | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Alamania | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Alangium | Cornales | Mabberley (2008) | Cornaceae. | ICBN |
| Alania | Asparagales | Mabberley (2008) | Boryaceae. | ICBN |
| Alantsilodendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Alanwoodia | Involutinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992); Sen Gupta (1999) | Planispirillinidae. | ICZN |
| Alaonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Alario | Passeriformes | Clements (2007) | . | ICZN |
| Alaspora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Alatocladia | Corallinales | Schneider & Wynne (2007) | . | ICBN |
| Alatoseta | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alatospora | Bivalvulida | Lom & Dyková (2006) | . | ICZN |
| Alatotrochus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Alauda | Passeriformes | Clements (2007) | . | ICZN |
| Alaxinus | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Albanemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Albaretia | Clevelandellida | Lynn (2008) | . | ICZN |
| Albatrossiella | Tintinnida | Lynn (2008) | . | ICZN |
| Albericus | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Alberta | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Albertia | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Albertinia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Albertisella | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Albertisia | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Albibacter | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Albidiferax | Burkholderiales | Ramana & Sasikala (2009) | Corrected name of "Albidoferax". | ICNB |
| Albidovulum | Rhodobacterales | Garrity et al. (2005) | . | ICNB |
| Albimonas | Rhodobacterales | Lim et al. (2008) | . | ICNB |
| Albizia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Albraunia | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Albrightia | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Albugo | Albuginales | Dick (2001); Kirk et al. (2008) | Albuginaceae. | ICBN |
| Alca | Charadriiformes | Clements (2007) | . | ICZN |
| Alcaligenes | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Alcalilimnicola | Chromatiales | Garrity et al. (2005) | Incorrectspelling of Alkalilimnicola. | ICNB |
| Alcanivorax | Oceanospirillales | Garrity et al. (2005) | . | ICNB |
| Alcantarea | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Alcea | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Alcedo | Coraciiformes | Clements (2007) | . | ICZN |
| Alcelaphus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Alces | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Alchemilla | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Alchornea | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Alchorneopsis | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Alcippe | Passeriformes | Clements (2007) | . | ICZN |
| Alcyonium | Alcyonacea | Bayer (1981) | Alcyoniidae. | ICZN |
| Aldama | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aldersladum | Alcyonacea | Benayahu & McFadden (2011) | Alcyoniidae. | ICZN |
| Aldina | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aldrovanda | Caryophyllales | Mabberley (2008) | Droseraceae. | ICBN |
| Aleadryas | Passeriformes | Clements (2007) | . | ICZN |
| Alectona | Hadromerida | Rützler (2002) | . | ICZN |
| Alectoris | Galliformes | Clements (2007) | . | ICZN |
| Alectra | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Alectroenas | Columbiformes | Clements (2007) | . | ICZN |
| Alectrurus | Passeriformes | Clements (2007) | . | ICZN |
| Alectryon | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Alectura | Galliformes | Clements (2007) | . | ICZN |
| Aleisanthia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aleisanthiopsis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Alepidea | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Alepidocline | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alepiella | Tectofilosida | Meisterfeld (2000); Cavalier-Smith & Chao (2003) | Psammonobiotidae. | ICZN |
| Alepis | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Alertigorgia | Alcyonacea | Bayer (1981) | Anthothelidae. | ICZN |
| Aletes | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Alethe | Passeriformes | Clements (2007) | . | ICZN |
| Aletris | Dioscoreales | Mabberley (2008) | Nartheciaceae. | ICBN |
| Aleurites | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Aleuritopteris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Alexanderina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Pseudoparrellidae. | ICZN |
| Alexandrium | Gonyaulacales | Fensome et al. (1993) | . | ICBN |
| Alexandronemertes | Pelagica | Gibson (1995) | . | ICZN |
| Alexfloydia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Alexgeorgea | Poales | Mabberley (2008) | Restionaceae. | ICBN |
| Alexteroon | Anura | Vitt & Caldwell (2009) | Hyperoliidae. | ICZN |
| Alfaroa | Fagales | Mabberley (2008) | Juglandaceae. | ICBN |
| Alfredia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alfredosilvestris | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nodosariidae. | ICZN |
| Alfvenia | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Algaria | Pottiales | Hedderson & Zander (2008) | . | ICBN |
| Algernonia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Algibacter | Flavobacteriales | Nedashkovskaya et al. (2004) | . | ICNB |
| Algicola | Alteromonadales | Ivanova et al. (2004) | . | ICNB |
| Algiphilus | Xanthomonadales | Gutierrez et al. (2012) | . | ICNB |
| Algirosphaera | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Rhabdosphaeraceae. | ICBN |
| Algonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Algoriphagus | Cytophagales | Bowman et al. (2003); Van Trappen et al. (2004); Ludwig et al. (2011) | . | ICNB |
| Algovora | Algovorida | Cavalier-Smith & Chao (2004) | . | ICZN |
| Algyroides | Squamata | Vitt & Caldwell (2009) | Lacertidae. | ICZN |
| Alhagi | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aliagarivorans | Alteromonadales | Jean et al. (2009) | . | ICNB |
| Alibertia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Alicia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Aliciella | Ericales | Mabberley (2008) | Polemoniaceae. | ICBN |
| Alicycliphilus | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Alicyclobacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Aliella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aligera | Dipsacales | Mabberley (2008) | Caprifoliaceae. | ICBN |
| Aligrimmia | Grimmiales | Goffinet et al. (2009) | . | ICBN |
| Aliidiomarina | Alteromonadales | Huang et al. (2012) | . | ICNB |
| Aliivibrio | Vibrionales | Urbanczyk et al. (2007) | . | ICNB |
| Alinula | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Aliona | Neogregarinorida | Perkins et al. (2000); Özdikmen (2009) | Substitute name for Schizocystis. | ICZN |
| Alionycteris | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Aliopsis | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Alishewanella | Chromatiales | Garrity et al. (2005); Ma et al. (2007) | Phylogenetically related to species of Chromatiales, but classified in Alteromonadales. | ICNB |
| Alisma | Alismatales | Mabberley (2008) | Alismataceae. | ICBN |
| Alisphaera | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Alisphaeraceae ?. | ICBN |
| Alisterus | Psittaciformes | Clements (2007) | . | ICZN |
| Alistilus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Alistipes | Bacteroidales | Rautio et al. (2003) | . | ICNB |
| Alkalibacillus | Bacillales | Jeon et al. (2005) | . | ICNB |
| Alkalibacter | Clostridiales | Garnova et al. (2004) | . | ICNB |
| Alkalibacterium | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Alkalibaculum | Clostridiales | Allen et al. (2010) | . | ICNB |
| Alkaliflexus | Bacteroidales | Zhilina et al. (2004) | . | ICNB |
| Alkalilimnicola | Chromatiales | Garrity et al. (2005) | . | ICNB |
| Alkalimonas | Chromatiales | Ma et al. (2007) | Phylogenetically related to species of Chromatiales. | ICNB |
| Alkaliphilus | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Alkalispirillum | Chromatiales | Garrity et al. (2005) | . | ICNB |
| Alkalitalea | Bacteroidales | Zhao & Chen (2012) | . | ICNB |
| Alkanibacter | Xanthomonadales | Friedrich & Lipski (2008) | . | ICNB |
| Alkanindiges | Pseudomonadales | Bogan et al. (2003) | . | ICNB |
| Alkanna | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Allactaga | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Allactodipus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Allagopappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Allagoptera | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Allamanda | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Allanblackia | Malpighiales | Mabberley (2008) | Guttiferae. | ICBN |
| Allanhancockia | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Glandulinidae. | ICZN |
| Allantactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Allantion | Glissomonadida | Howe et al. (2009) | . | ICZN |
| Allantocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Allantoma | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Allantosoma | Exogenida | Lynn (2008) | . | ICZN |
| Allantospermum | Malpighiales | Mabberley (2008) | Ixonanthaceae. | ICBN |
| Allantoxena | Exogenida | Lynn (2008) | . | ICZN |
| Allapasus | Helminthomorpha | Holland et al. (2012) | Torquaratoridae. | ICZN |
| Allapsa | Glissomonadida | Howe et al. (2009) | . | ICZN |
| Allardia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Allas | Thaumatomonadida | Howe et al. (2011) | . | ICZN |
| Alle | Charadriiformes | Clements (2007) | . | ICZN |
| Alleizettella | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Allenanthus | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Allenia | Passeriformes | Clements (2007) | . | ICZN |
| Allenopithecus | Primates | McKenna & Bell (1997) | . | ICZN |
| Allenrolfea | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Allexis | Malpighiales | Mabberley (2008) | Violaceae. | ICBN |
| Alleynea | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Alliaria | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Alliatina | Robertinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Robertinidae. | ICZN |
| Alliatinella | Robertinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Robertinidae. | ICZN |
| Alligator | Crocodylia | Vitt & Caldwell (2009) | Alligatoridae. | ICZN |
| Allionia | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Allioniellopsis | Hypnales | Greuter et al. (1993); Goffinet et al. (2009) | Not Allionellopsis (Greuter et al., 1993). | ICBN |
| Allisonella | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Allisonia | Fossombroniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Allisoniella | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Allittia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Allium | Asparagales | Mabberley (2008) | Alliaceae. | ICBN |
| Allmania | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Allmaniopsis | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Alloactinosynnema | Pseudonocardiales | Yuan et al. (2010); Ludwig et al. (2012) | . | ICNB |
| Allobacillus | Bacillales | Sheu et al. (2011) | . | ICNB |
| Allobaculum | Erysipelotrichales | Greetham et al. (2004); Ludwig et al. (2009) | . | ICNB |
| Allobates | Anura | Vitt & Caldwell (2009) | Aromobatidae. | ICZN |
| Allocassine | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Allocasuarina | Fagales | Mabberley (2008) | Casuarinaceae. | ICBN |
| Allocatelliglobosispora | Micromonosporales | Lee & Lee (2011); Ludwig et al. (2012) | Micromonosporaceae. | ICNB |
| Allocebus | Primates | McKenna & Bell (1997) | . | ICZN |
| Allocheilos | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Allochromatium | Chromatiales | Garrity et al. (2005) | . | ICNB |
| Allochrusa | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Allocricetulus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Alloeocarpa | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Styelidae. | ICZN |
| Alloeochaete | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Allofustis | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Alloglobigerinoides | Globigerinida | Huang (1986); Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Globigerinacea. | ICZN |
| Alloglugea | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Allogromia | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Allogromiidae. | ICZN |
| Alloiococcus | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Alloiozona | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Alloispermum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Allokutzneria | Pseudonocardiales | Labeda & Kroppenstedt (2008); Ludwig et al. (2012) | . | ICNB |
| Allolepis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Allomaieta | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Allomarkgrafia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Allomonas | Vibrionales | Garrity et al. (2005) | . | ICNB |
| Allomorphia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Allomorphina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Chilostomellidae. | ICZN |
| Alloneuron | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Allopaa | Anura | Vitt & Caldwell (2009) | Dicroglossidae. | ICZN |
| Allopathes | Antipatharia | Bo et al. (2009) | "110608". | ICZN |
| Allophryne | Anura | Vitt & Caldwell (2009) | Centrolenidae. | ICZN |
| Allophyllum | Ericales | Mabberley (2008) | Polemoniaceae. | ICBN |
| Allophylus | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Alloplectus | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Allopterigeron | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Allorathkea | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Allorgeia | Desmidiales | Gontcharov (2008) | . | ICBN |
| Allorhadinorhynchus | Echinorhynchida | Amin (1985) | . | ICZN |
| Allorhizobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Allosanthus | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Alloscardovia | Bifidobacteriales | Huys et al. (2007); Ludwig et al. (2012) | . | ICNB |
| Alloschemone | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Alloschmidia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Allosidastrum | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Allosphaerium | Dysteriida | Lynn (2008) | . | ICZN |
| Allostigma | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Allosyncarpia | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Alloteropsis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Allotricha | Sporadotrichida | Lynn (2008) | . | ICZN |
| Allotropa | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Allovahlkampfia | Schizopyrenida | Walochnik & Mulec (2009) | . | ICZN |
| Allowissadula | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Allowoodsonia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Alloxylon | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Alluaudia | Caryophyllales | Mabberley (2008) | Didiereaceae. | ICBN |
| Alluaudina | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Alluaudiopsis | Caryophyllales | Mabberley (2008) | Didiereaceae. | ICBN |
| Alluna | Acoela | Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Almaleea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Almeidea | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Almophrya | Astomatida | Lynn (2008) | . | ICZN |
| Almutaster | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alniphyllum | Ericales | Mabberley (2008) | Styracaceae. | ICBN |
| Alnus | Fagales | Mabberley (2008) | Betulaceae. | ICBN |
| Alobiella | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Alobiellopsis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Alocasia | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Alococarpum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Alocodera | Arcellinida | Meisterfeld (2000) | Difflugina -- Nebelidae. | ICZN |
| Aloe | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Aloina | Pottiales | Greuter et al. (1993); Goffinet et al. (2009) | Not "Aloinia" (Greuter et al., 1993). | ICBN |
| Aloinella | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Aloinopsis | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Alomia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alomiella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alonsoa | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Alopecurus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Alophia | Asparagales | Mabberley (2008) | Iridaceae. | ICBN |
| Alophoixus | Passeriformes | Clements (2007) | . | ICZN |
| Alophosia | Polytrichales | Greuter et al. (1993); Goffinet et al. (2009) | Not "Alophozia" (Greuter et al., 1993). | ICBN |
| Alopias | Lamniformes | Nelson (2006) | . | ICZN |
| Alopochelidon | Passeriformes | Clements (2007) | . | ICZN |
| Alopochen | Anseriformes | Clements (2007) | . | ICZN |
| Alopoglossus | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Alouatta | Primates | McKenna & Bell (1997) | . | ICZN |
| Aloysia | Lamiales | Mabberley (2008) | Verbenaceae. | ICBN |
| Alphamonas | Voromonadida | Cavalier-Smith & Chao (2004) | . | ICZN |
| Alphandia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Alphitonia | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Alphonsea | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Alpinia | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Alpinimonas | Micrococcales | Schumann et al. (2012) | . | ICNB |
| Alrawia | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Alseianthiopsis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Alseis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Alseodaphne | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Alseuosmia | Asterales | Mabberley (2008) | Alseuosmiaceae. | ICBN |
| Alsia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Alsidium | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Alsobia | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Alsodeiopsis | Icacinales | Mabberley (2008) | Icacinaceae. | ICBN |
| Alsodes | Anura | Vitt & Caldwell (2009) | Cycloramphidae. | ICZN |
| Alsomitra | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Alsophila | Cyatheales | Christenhusz et al. (2011) | . | ICBN |
| Alsophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Alsophylax | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Alstonia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Alstroemeria | Liliales | Mabberley (2008) | Alstroemeriaceae. | ICBN |
| Altensteinia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Alterammina | Trochamminida | Kaminski (2000) | Trochamminellinae, Trochamminacea. | ICZN |
| Altererythrobacter | Sphingomonadales | Kwon et al. (2007) | . | ICNB |
| Alteribacillus | Bacillales | Didari et al. (2012) | . | ICNB |
| Alternanthera | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Alternantia | Synechococcales | Yamagishi (2007) | . | ICBN |
| Alterococcus | Opitutales | Garrity et al. (2005); Choo et al. (2007) | . | ICNB |
| Alteromonas | Alteromonadales | Garrity et al. (2005) | . | ICNB |
| Althaea | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Althenia | Alismatales | Mabberley (2008) | Potamogetonaceae. | ICBN |
| Althoffia | Appendicularia | Fenaux (1998) | . | ICZN |
| Althornia | Thraustochytriales | Dick (2001); Kirk et al. (2008) | Thraustochytriaceae. | ICBN |
| Alticola | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Altingia | Saxifragales | Mabberley (2008) | Hamamelidaceae. | ICBN |
| Altiphrynoides | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Altoparadisium | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aluta | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Alvaradoa | Picramniales | Mabberley (2008) | Picramniaceae. | ICBN |
| Alveolinella | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Alveolinidae. | ICZN |
| Alveolophragmium | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Cyclamminidae. | ICZN |
| Alveopora | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Alveosphaera | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Calciosoleniaceae. | ICBN |
| Alvesia | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Alvimia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Alvimiantha | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Alvordia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Alyogyne | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Alysicarpus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Alysiella | Neisseriales | Garrity et al. (2005) | . | ICNB |
| Alyssoides | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Alyssopsis | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Alyssum | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Alytes | Anura | Vitt & Caldwell (2009) | Alytidae. | ICZN |
| Alyxia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Alzatea | Myrtales | Mabberley (2008) | Crypteroniaceae. | ICBN |
| Amadina | Passeriformes | Clements (2007) | . | ICZN |
| Amaioua | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Amalocalyx | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Amalocichla | Passeriformes | Clements (2007) | . | ICZN |
| Amandava | Passeriformes | Clements (2007) | . | ICZN |
| Amanoa | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Amansia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Amapacanthus | Echinorhynchida | Salgado-Maldonado & Santos (2000) | Diplosentidae. | ICZN |
| Amapasaurus | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Amaracarpus | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Amaranthus | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Amarcrinum | Asparagales | Mabberley (2008) | xAmarcrinum. Amaryllis x Crinum hybrids. Amaryllidaceae. | ICBN |
| Amaricoccus | Rhodobacterales | Garrity et al. (2005) | . | ICNB |
| Amaristes | Asparagales | Mabberley (2008) | xAmaristes. Amaryllis x Cybistetes hybrids. Amaryllidaceae. | ICBN |
| Amarygia | Asparagales | Mabberley (2008) | xAmarygia. Amaryllis x Brunsvigia hybrids. Amaryllidaceae. | ICBN |
| Amaryllis | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Amasonia | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Amastigomonas | Apusomonadida | Cavalier-Smith et al. (2008) | . | ICZN |
| Amastridium | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Amauria | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amauriopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amaurochaete | Stemonitales | Yamamoto (1998); Lado (2001); Lado et al. (2005) | . | ICBN |
| Amaurocichla | Passeriformes | Clements (2007) | . | ICZN |
| Amaurolimnas | Gruiformes | Clements (2007) | . | ICZN |
| Amaurornis | Gruiformes | Clements (2007) | . | ICZN |
| Amaurospiza | Passeriformes | Clements (2007) | . | ICZN |
| Amazilia | Apodiformes | Clements (2007) | . | ICZN |
| Amazona | Psittaciformes | Clements (2007) | . | ICZN |
| Amazonetta | Anseriformes | Clements (2007) | . | ICZN |
| Amazoopsis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Ambavia | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Ambelania | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Amberboa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ambiphrya | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Ambitropus | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Pseudoparrellidae. | ICZN |
| Amblonyx | Carnivora | McKenna & Bell (1997); Wozencraft (2005) | Later synonym of Aonyx. | ICZN |
| Amblyanthopsis | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Amblyanthus | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Amblycercus | Passeriformes | Clements (2007) | . | ICZN |
| Amblygonocarpus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amblynotus | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Amblyocarpum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amblyodipsas | Squamata | Vitt & Caldwell (2009) | Serpentes. Atractaspididae. | ICZN |
| Amblyodon | Splachnales | Goffinet et al. (2009) | . | ICBN |
| Amblyolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Amblyolepis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amblyopappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amblyopetalum | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Amblyornis | Passeriformes | Clements (2007) | . | ICZN |
| Amblyospiza | Passeriformes | Clements (2007) | . | ICZN |
| Amblyospora | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Amblyraja | Rajiformes | Nelson (2006) | . | ICZN |
| Amblyramphus | Passeriformes | Clements (2007) | . | ICZN |
| Amblyrhynchus | Squamata | Vitt & Caldwell (2009) | Iguanidae. | ICZN |
| Amblysomus | Afrosoricida | McKenna & Bell (1997); Stanhope et al. (1998) | Chrysochloridea. | ICZN |
| Amblysperma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amblystegium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Amblystigma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Amblytropis | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Ambongia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Amborella | Amborellales | Mabberley (2008) | Amborellaceae. | ICBN |
| Amboroa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ambrella | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ambrosia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ambrosina | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Ambuchanania | Ambuchananiales | Goffinet et al. (2009) | . | ICBN |
| Amburana | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Ambystoma | Caudata | Vitt & Caldwell (2009) | Ambystomatidae. | ICZN |
| Ameerega | Anura | Vitt & Caldwell (2009) | Dendrobatidae. | ICZN |
| Ameghinoa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ameiva | Squamata | Vitt & Caldwell (2009) | Teiidae. | ICZN |
| Amelanchier | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Amelichloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Amellus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amentotaxus | Cupressales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Ameroglossum | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Amerorchis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Amesiella | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Amesiodendron | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Ameson | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Amethystea | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Ametrida | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Ameyamaea | Rhodospirillales | Yukphan et al. (2009) | . | ICNB |
| Amherstia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amianthum | Liliales | Mabberley (2008) | Melanthiaceae. | ICBN |
| Amicia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amieta | Thigmotrichida | Lynn (2008) | . | ICZN |
| Amietia | Anura | Vitt & Caldwell (2009) | Pyxicephalidae. | ICZN |
| Amietophrynus | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Aminiphilus | Synergistales | Díaz et al. (2007); Jumas-Bilak et al. (2009) | . | ICNB |
| Aminobacter | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Aminobacterium | Synergistales | Garrity et al. (2005); Jumas-Bilak et al. (2007); Jumas-Bilak et al. (2009) | . | ICNB |
| Aminomonas | Synergistales | Garrity et al. (2005); Jumas-Bilak et al. (2007); Jumas-Bilak et al. (2009) | . | ICNB |
| Amischotolype | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Amitostigma | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ammandra | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Ammannia | Myrtales | Mabberley (2008) | Lythraceae. | ICBN |
| Ammatoidea | Oscillatoriales | Hoffmann et al. (2005) | . | ICBN |
| Ammi | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Ammoastuta | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lituolidae. | ICZN |
| Ammobaculinus | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammobaculinidae. | ICZN |
| Ammobaculites | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lituolidae. | ICZN |
| Ammobium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ammocalamagrostis | Poales | Mabberley (2008) | xAmmocalamagrostis. Ammophila x Calamagrostis hybrids. Gramineae. | ICBN |
| Ammocharis | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Ammochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ammocibicides | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Placopsilinidae. | ICZN |
| Ammocibicoides | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Placopsilinidae. | ICZN |
| Ammodaucus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Ammodendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Ammodillus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Ammodiscellites | Lituolida | Kaminski (2004) | Tolypammininae, Ammodiscacea. | ICZN |
| Ammodiscoides | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammodiscidae. | ICZN |
| Ammodiscus | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammodiscidae. | ICZN |
| Ammodorcas | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Ammodramus | Passeriformes | Clements (2007) | . | ICZN |
| Ammoflintina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Rzehakinidae. | ICZN |
| Ammoglobigerina | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Trochamminidae. | ICZN |
| Ammogloborotalia | Trochamminida | Kaminski (2008) | Trochammininae. | ICZN |
| Ammoides | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Ammolagena | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammodiscidae. | ICZN |
| Ammolineus | Heteronemertea | Kajihara et al. (2008) | . | ICZN |
| Ammomanes | Passeriformes | Clements (2007) | . | ICZN |
| Ammomanopsis | Passeriformes | Clements (2007) | . | ICZN |
| Ammomarginulina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lituolidae. | ICZN |
| Ammomassilina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Ammonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Ammonia | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Rotaliidae. | ICZN |
| Ammonifex | Thermoanaerobacterales | Garrity et al. (2005); Ludwig et al. (2009) | . | ICNB |
| Ammoniphilus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Ammopemphix | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hemisphaeramminidae. | ICZN |
| Ammoperdix | Galliformes | Clements (2007) | . | ICZN |
| Ammophila | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ammopiptanthus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Ammoscalaria | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Discamminidae. | ICZN |
| Ammoselinum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Ammosperma | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Ammospermophilus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Ammosphaeroidina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammosphaeroidinidae. | ICZN |
| Ammosphaerulina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Sphaeramminidae. | ICZN |
| Ammothamnus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Ammotium | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lituolidae. | ICZN |
| Ammotragus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Ammotrochoides | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Coscinophragmatidae. | ICZN |
| Ammovertellina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammodiscidae. Holocene?. | ICZN |
| Amnibacterium | Micrococcales | Kim & Lee (2011); Ludwig et al. (2012) | Microbacteriaceae. | ICNB |
| Amniclineus | Heteronemertea | Gibson (1995) | . | ICZN |
| Amoeba | Euamoebida | Rogerson & Patterson (2000); Smirnov et al. (2005) | . | ICZN |
| Amoebidium | Ichthyophonida | Mendoza et al. (2002) | . | ICZN |
| Amoeboaphelidium | Aphelidida | Gromov (2000) | . | ICZN |
| Amoebobacter | Chromatiales | Garrity et al. (2005) | . | ICNB |
| Amoebogregarina | Eugregarinorida | Kula & Clopton (1999) | . | ICZN |
| Amoebophrya | Syndinida | Fensome et al. (1993) | . | ICZN |
| Amoenoscopa | Acanthoecida | Leadbeater & Thomsen (2000) | . | ICZN |
| Amoenothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Amolinia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amolops | Anura | Vitt & Caldwell (2009) | Ranidae. | ICZN |
| Amomum | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Amomyrtella | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Amomyrtus | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Amoreuxia | Malvales | Mabberley (2008) | Bixaceae. | ICBN |
| Amorpha | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amorphinopsis | Halichondrida | Erpenbeck & Van Soest (2002) | . | ICZN |
| Amorphochilus | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Amorphochlora | Chlorarachniales | Ishida et al. (2011) | . | ICBN |
| Amorphonemertes | Heteronemertea | Kajihara et al. (2008) | . | ICZN |
| Amorphophallus | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Amorphus | Rhizobiales | Zeevi Ben Yosef et al. (2008) | . | ICNB |
| Amparoa | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ampelaster | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ampeliceps | Passeriformes | Clements (2007) | . | ICZN |
| Ampelioides | Passeriformes | Clements (2007) | . | ICZN |
| Ampelion | Passeriformes | Clements (2007) | . | ICZN |
| Ampelocalamus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ampelocera | Rosales | Mabberley (2008) | Ulmaceae. | ICBN |
| Ampelocissus | Vitales | Mabberley (2008) | Vitaceae. | ICBN |
| Ampelodesmos | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ampelopsis | Vitales | Mabberley (2008) | Vitaceae. | ICBN |
| Ampelosycios | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Ampelozizyphus | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Amperea | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Amphiacantha | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Amphiachyris | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amphiacme | Pennatulacea | Williams (1995) | . | ICZN |
| Amphiacon | Chaunacanthida | Febvre et al. (2000) | . | ICZN |
| Amphiactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Amphiamblys | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Amphianthus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Amphianthus | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Amphiasma | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Amphiastrella | Poecilosclerida | Van Soest (2002) | . | ICZN |
| Amphibacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Amphibelone | Symphyacanthida | Febvre et al. (2000) | . | ICZN |
| Amphibiocystidium | Dermocystida | Pereira et al. (2005) | . | ICZN |
| Amphibiothecum | Dermocystida | Feldman et al. (2005) | . | ICZN |
| Amphiblemma | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Amphibleptula | | Pisera & Lévi (2002) | Domain Eucarya - Kingdom Animalia - Phylum Porifera - Class Demospongiae (lithistids) Scleritodermidae. | ICZN |
| Amphibolia | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Amphibolis | Alismatales | Mabberley (2008) | Cymodoceaceae. | ICBN |
| Amphibolurus | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Amphibolus | Parachela | Kinchin (1994); Özdikmen (2008) | Junior homonym. Replaced by Bertolanius. | ICZN |
| Amphibothrella | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora - Class Prostomatea. | ICZN |
| Amphibromus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Amphicarpa | Stolidobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Stolonica. | ICZN |
| Amphicarpaea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amphicarpum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Amphicaryon | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Amphicephalozia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Amphichrysis | Chromulinales | Kristiansen & Preisig (2001) | Chromulinaceae (uniflagellate). | ICBN |
| Amphicoryna | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Vaginulinidae. | ICZN |
| Amphidasya | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Amphidiniella | Gonyaulacales | Horiguchi (1995) | . | ICBN |
| Amphidiniopsis | Peridiniales | Fensome et al. (1993) | . | ICBN |
| Amphidinium | Gymnodiniales | Fensome et al. (1993) | . | ICBN |
| Amphidiscella | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Amphidium | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Amphidoma | Gonyaulacales | Fensome et al. (1993) | . | ICBN |
| Amphiesma | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Amphiesmoides | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Amphifenestrella | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Astrorhizidae. | ICZN |
| Amphiglossa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amphiglossus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Amphikrikos | Chlorellales | Darienko et al. (2010); Pažoutová et al. (2010) | As Oocystis-clade or Oocystaceae. | ICBN |
| Amphilaphis | Alcyonacea | Bayer (1981) | Primnoidae. | ICZN |
| Amphilectus | Poecilosclerida | Van Soest & Hajdu (2002) | . | ICZN |
| Amphileptiscus | Pleurostomatida | Lynn (2008) | . | ICZN |
| Amphileptus | Pleurostomatida | Lynn (2008) | . | ICZN |
| Amphilithium | Symphyacanthida | Febvre et al. (2000) | . | ICZN |
| Amphilonche | Arthracanthida | Febvre et al. (2000) | . | ICZN |
| Amphilophium | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Amphilophocolea | Jungermanniales | Crandall-Stotler et al. (2009); Engel et al. (2010) | Later synonym of Heteroscyphus. | ICBN |
| Amphimas | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amphimedon | Haplosclerida | Desqueyroux-Faúndez & Valentine (2002) | . | ICZN |
| Amphimorphina | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nodosariidae. | ICZN |
| Amphinectomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Amphinema | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Amphinemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Amphinomia | Poecilosclerida | Hooper (2002) | . | ICZN |
| Amphipappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amphipetalum | Caryophyllales | Mabberley (2008) | Portulacaceae. | ICBN |
| Amphiphyllum | Poales | Mabberley (2008) | Rapateaceae. | ICBN |
| Amphiplatyspora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Amphiplexia | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Amphipogon | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Amphiporella | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Amphiporus | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Amphipterygium | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Amphirhiza | Chromulinales | Kristiansen & Preisig (2001) | Chrysamoebaceae (uniflagellate). | ICBN |
| Amphirhopalum | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Amphiroa | Corallinales | Schneider & Wynne (2007) | . | ICBN |
| Amphirrhox | Malpighiales | Mabberley (2008) | Violaceae. | ICBN |
| Amphisbaena | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Amphisbetema | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Amphisbetia | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Amphiscirpus | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Amphiscolops | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Amphisiella | Stichotrichida | Lynn (2008) | . | ICZN |
| Amphisiellides | Stichotrichida | Lynn (2008) | . | ICZN |
| Amphisolenia | Dinophysiales | Fensome et al. (1993) | . | ICBN |
| Amphisorus | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Soritidae. | ICZN |
| Amphispiza | Passeriformes | Clements (2007) | . | ICZN |
| Amphistaurus | Arthracanthida | Febvre et al. (2000) | . | ICZN |
| Amphistegina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Amphisteginidae. | ICZN |
| Amphitecta | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Amphitethya | Spirophorida | Van Soest & Rützler (2002) | . | ICZN |
| Amphithalea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Amphitholus | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Amphitrema | Tectofilosida | Meisterfeld (2000); Cavalier-Smith & Chao (2003) | Amphitremidae. | ICZN |
| Amphiuma | Caudata | Vitt & Caldwell (2009) | Amphiumidae. | ICZN |
| Amphiute | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Amphizonella | Arcellinida | Meisterfeld (2000) | Arcellina -- Microcoryciidae. | ICZN |
| Amphogona | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Amphorellopsis | Tintinnida | Lynn (2008) | . | ICZN |
| Amphoricarpos | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Amphorides | Tintinnida | Lynn (2008) | . | ICZN |
| Amphoriscus | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Amphorocalyx | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Amphorocephalus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Amphorogyne | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Amphoroides | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Amphritea | Oceanospirillales | Gärtner et al. (2008) | . | ICNB |
| Amplectella | Tintinnida | Lynn (2008) | . | ICZN |
| Amplectellopsis | Tintinnida | Lynn (2008) | . | ICZN |
| Amplexidiscus | Corallimorpharia | Fautin et al. (2007) | . | ICZN |
| Amplisiphonia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Amplorhinus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Ampullacula | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Ampullataria | Euglyphida | Meisterfeld (2000) | . | ICZN |
| Ampullofolliculina | Heterotrichida | Lynn (2008) | . | ICZN |
| Amscottia | Desmidiales | Gontcharov (2008) | . | ICBN |
| Amsinckia | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Amsonia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Amycolatopsis | Pseudonocardiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Amycolicicoccus | Corynebacteriales | Wang et al. (2010); Ludwig et al. (2012) | Mycobacteriaceae. | ICNB |
| Amyda | Testudinata | Vitt & Caldwell (2009) | Trionychidae. | ICZN |
| Amydrium | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Amyema | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Amylax | Gonyaulacales | Fensome et al. (1993) | . | ICBN |
| Amyloodinium | Peridiniales | Fensome et al. (1993); Levy et al. (2007) | . | ICBN |
| Amylophorus | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Amylotheca | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Amylovorax | Macropodiniida | Lynn (2008) | . | ICZN |
| Amyrea | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Amyris | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Amytornis | Passeriformes | Clements (2007) | . | ICZN |
| Amyxa | Malvales | Mabberley (2008) | Thymelaeaceae. | ICBN |
| Anabacerthia | Passeriformes | Clements (2007) | . | ICZN |
| Anabaena | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Anabaenopsis | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Anabasis | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Anabathmis | Passeriformes | Clements (2007) | . | ICZN |
| Anabazenops | Passeriformes | Clements (2007) | . | ICZN |
| Anacampseros | Caryophyllales | Mabberley (2008) | Portulacaceae. | ICBN |
| Anacamptis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anacamptodon | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Anacantha | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anacanthobatis | Rajiformes | Nelson (2006) | . | ICZN |
| Anacanthoderma | Chaetonotida | Balsamo et al. (2009) | . | ICZN |
| Anacanthoica | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Rhabdosphaeraceae. | ICBN |
| Anacaona | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Anacardium | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Anacharon | Vestibuliferida | Lynn (2008) | . | ICZN |
| Anacolia | Bartramiales | Goffinet et al. (2009) | . | ICBN |
| Anacolosa | Santalales | Mabberley (2008) | Olacaceae. | ICBN |
| Anacropora | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Anactinia | Ceriantharia | Tiffon (1987) | . | ICZN |
| Anacyclus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anadelphia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anadenanthera | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Anadendrum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anaderma | | Pisera & Lévi (2002) | Domain Eucarya - Kingdom Animalia - Phylum Porifera - Class Demospongiae (lithistids) Pleromidae. | ICZN |
| Anadia | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Anadistoma | Aplousobranchia | Kott (1998) | Pseudodistomidae. | ICZN |
| Anaectocalyx | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Anaeroarcus | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Anaerobacillus | Bacillales | Zavarzina et al. (2009) | . | ICNB |
| Anaerobacter | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anaerobaculum | Synergistales | Garrity et al. (2005); Jumas-Bilak et al. (2007); Jumas-Bilak et al. (2009) | . | ICNB |
| Anaerobiospirillum | Aeromonadales | Garrity et al. (2005) | . | ICNB |
| Anaerobranca | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anaerococcus | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anaerofilum | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anaerofustis | Clostridiales | Finegold et al. (2004) | . | ICNB |
| Anaeroglobus | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Anaerolinea | Anaerolineales | Sekiguchi et al. (2003); Yamada et al. (2006) | . | ICNB |
| Anaeromusa | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Anaeromyxobacter | Myxococcales | Garrity et al. (2005) | . | ICNB |
| Anaerophaga | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Anaeroplasma | Anaeroplasmatales | Garrity et al. (2005) | . | ICNB |
| Anaerorhabdus | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Anaerosalibacter | Clostridiales | Rezgui et al. (2012) | . | ICNB |
| Anaerosinus | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Anaerosphaera | Clostridiales | Ueki et al. (2009) | . | ICNB |
| Anaerosporobacter | Clostridiales | Jeong et al. (2007) | . | ICNB |
| Anaerostipes | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anaerotruncus | Clostridiales | Lawson et al. (2004) | . | ICNB |
| Anaerovibrio | Selenomonadales | Garrity et al. (2005); Marchandin et al. (2010) | . | ICNB |
| Anaerovirgula | Clostridiales | Pikuta et al. (2006) | . | ICNB |
| Anaerovorax | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Anagallis | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Anagyris | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Anairetes | Passeriformes | Clements (2007) | . | ICZN |
| Anakasia | Apiales | Mabberley (2008) | Araliaceae. | ICBN |
| Anamirta | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Anamixilla | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Ananas | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Ananthacorus | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Anaperus | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Anaphalis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anaphaloides | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anaphyllopsis | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anaphyllum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anaplasma | Rickettsiales | Garrity et al. (2005) | . | ICNB |
| Anaplectes | Passeriformes | Clements (2007) | . | ICZN |
| Anarhynchus | Charadriiformes | Clements (2007) | . | ICZN |
| Anarma | Endogenida | Lynn (2008) | . | ICZN |
| Anarrhinum | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Anarthria | Poales | Mabberley (2008) | Anarthriaceae. | ICBN |
| Anarthroclada | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Anarthrophyllum | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Anas | Anseriformes | Clements (2007) | . | ICZN |
| Anastatica | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Anastomus | Ciconiiformes | Clements (2007) | . | ICZN |
| Anastrabe | Lamiales | Mabberley (2008) | Stilbaceae. | ICBN |
| Anastrepta | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anastrophyllum | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anathana | Scandentia | McKenna & Bell (1997) | . | ICZN |
| Anatheca | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Anathece | Synechococcales | Komárek et al. (2011) | . | ICBN |
| Anatherostipa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anatoliocirrus | Sporadotrichida | Lynn (2008) | . | ICZN |
| Anatropanthus | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Anaxagorea | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Anaxeton | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anaxyrus | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Ancalochloris | Chlorobiales | Garrity et al. (2005) | . | ICNB |
| Ancalomicrobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Ancathia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anchietea | Malpighiales | Mabberley (2008) | Violaceae. | ICBN |
| Anchihauerina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Anchinia | Doliolida | Neumann (1913); Godeaux (1998) | Later homonym. Replaced by Doliopsis. | ICZN |
| Anchitestudinella | Flosculariaceae | Segers (2002); Segers (2007) | . | ICZN |
| Anchomanes | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anchonium | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Anchusa | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Anchusella | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Ancistrachne | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Ancistranthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Ancistrella | Thigmotrichida | Lynn (2008) | . | ICZN |
| Ancistrocarphus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ancistrocarpus | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Ancistrocarya | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Ancistrochilus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ancistrocladus | Caryophyllales | Mabberley (2008) | Ancistrocladaceae. | ICBN |
| Ancistrocoma | Rhynchodida | Lynn (2008) | . | ICZN |
| Ancistrodes | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Ancistrophora | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ancistrops | Passeriformes | Clements (2007) | . | ICZN |
| Ancistrorhynchus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ancistrospira | Thigmotrichida | Lynn (2008) | . | ICZN |
| Ancistrothyrsus | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Ancistrum | Thigmotrichida | Lynn (2008) | . | ICZN |
| Ancistrumina | Thigmotrichida | Lynn (2008) | . | ICZN |
| Ancora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Ancorella | Astrophorida | Maldonado (2002) | . | ICZN |
| Ancorina | Astrophorida | Uriz (2002) | . | ICZN |
| Ancylanthos | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Ancylobacter | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Ancylobotrys | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Ancylocirrus | Acoela | Hooge & Tyler (2005) | . | ICZN |
| Ancylocranium | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Ancylonema | Zygnematales | Gontcharov (2008) | . | ICBN |
| Ancylostemon | Lamiales | Mabberley (2008); Möller et al. (2011) | Gesneriaceae. Later synonym of Oreocharis. | ICBN |
| Ancylotropis | Fabales | Mabberley (2008) | Polygalaceae. | ICBN |
| Ancyromonas | Ancyromonadida | Heiss et al. (2010) | . | ICZN |
| Ancyrophora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Ancystropodium | Sporadotrichida | Lynn (2008) | . | ICZN |
| Andalgalomys | Rodentia | Musser & Carleton (2005) | . | ICZN |
| Andalucia | Jakobida | Lara et al. (2006) | . | ICZN |
| Anderbergia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anderseniella | Rhizobiales | Brettar et al. (2007) | . | ICNB |
| Andersonia | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Andigena | Piciformes | Clements (2007) | . | ICZN |
| Andinia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Andinomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Andinophryne | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Andira | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Andoa | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Andracantha | Polymorphida | Amin (1985) | . | ICZN |
| Andrachne | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Andradea | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Andrea | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Andreadoxa | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Andreaea | Andreaeales | Goffinet et al. (2009) | . | ICBN |
| Andreaeobryum | Andreaeobryales | Goffinet et al. (2009) | . | ICBN |
| Andreprevotia | Neisseriales | Weon et al. (2007) | . | ICNB |
| Andresia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Andreula | Philasterida | Lynn (2008) | . | ICZN |
| Andrewsianthus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Andriana | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Andrias | Caudata | Vitt & Caldwell (2009) | Cryptobranchidae. | ICZN |
| Androcalymma | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Androcorys | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Androdon | Apodiformes | Clements (2007) | . | ICZN |
| Andrographis | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Androlepis | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Andromeda | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Androngo | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Andropadus | Passeriformes | Clements (2007) | . | ICZN |
| Androphobus | Passeriformes | Clements (2007) | . | ICZN |
| Andropogon | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Andropterum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Androsace | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Androsina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Soritidae. | ICZN |
| Androsiphonia | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Androstachys | Malpighiales | Mabberley (2008) | Picrodendraceae. | ICBN |
| Androstephium | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Androstoma | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Androtium | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Androtrichum | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Androya | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Andrusoviella | Endogenida | Lynn (2008) | . | ICZN |
| Andryala | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Andrzeiowskia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Andvakia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anechites | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aneides | Caudata | Vitt & Caldwell (2009) | Plethodontidae. | ICZN |
| Aneilema | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Anelsonia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Anelytropsis | Squamata | Vitt & Caldwell (2009) | Dibamidae. | ICZN |
| Anemarrhena | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Anemia | Schizaeales | Christenhusz et al. (2011) | . | ICBN |
| Anemocarpa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anemonactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anemone | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Anemonella | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Anemonia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anemonopsis | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Anemopaegma | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Anemopsis | Piperales | Mabberley (2008) | Saururaceae. | ICBN |
| Anerincleistus | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Anetanthus | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Anetholea | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Anethum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Anetium | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Aneulophus | Malpighiales | Mabberley (2008) | Erythroxylaceae. | ICBN |
| Aneura | Metzgeriales | Crandall-Stotler et al. (2009) | . | ICBN |
| Aneurianna | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Aneurinibacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Angadenia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Angasomyrtus | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Angeiocystis | Protococcidiorida | Perkins et al. (2000) | . | ICZN |
| Angelica | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Angelonia | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Angelopsis | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Angelphytum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Angianthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anginon | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Angiopteris | Marattiales | Christenhusz et al. (2011) | . | ICBN |
| Angkalanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Anglasia | Astomatida | Lynn (2008) | . | ICZN |
| Angolaea | Malpighiales | Mabberley (2008) | Podostemaceae. | ICBN |
| Angomonas | Trypanosomatida | Teixeira et al. (2011) | . | ICZN |
| Angonoka | Testudinata | Vitt & Caldwell (2009) | Testudinidae. | ICZN |
| Angophora | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Angoseseli | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Angostura | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Angostylis | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Angraecopsis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Angraecum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anguis | Squamata | Vitt & Caldwell (2009) | Anguidae. | ICZN |
| Anguloa | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Angulochrysis | Ochromonadales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Dinobryaceae (uniflagellate). | ICBN |
| Angulodiscorbis | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Glabratellidae. | ICZN |
| Angulogerina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Uvigerinidae. | ICZN |
| Angulomicrobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Angursa | Arthrotardigrada | Kinchin (1994) | . | ICZN |
| Angustibacter | | Tamura et al. (2010); Ludwig et al. (2012) | Domain Bacteria - Kingdom Bacteria - Phylum Actinobacteria - Class Actinobacteria. Closely related to Kineosporiales and Micrococcales. | ICNB |
| Angylocalyx | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Anheteromeyenia | Haplosclerida | Manconi & Pronzato (2002) | . | ICZN |
| Anhima | Anseriformes | Clements (2007) | . | ICZN |
| Anhinga | Pelecaniformes | Clements (2007) | . | ICZN |
| Anhydrophryne | Anura | Vitt & Caldwell (2009) | Pyxicephalidae. | ICZN |
| Aniba | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Anictostoma | Colpodida | Lynn (2008) | Later synonym of Corallocolpoda?. | ICZN |
| Anigozanthos | Commelinales | Mabberley (2008) | Haemodoraceae. | ICBN |
| Anigsteinia | Heterotrichida | Lynn (2008) | . | ICZN |
| Anilius | Squamata | Vitt & Caldwell (2009) | Serpentes. Aniliidae. | ICZN |
| Anisacanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Anisadenia | Malpighiales | Mabberley (2008) | Linaceae. | ICBN |
| Anisantherina | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Aniseia | Solanales | Mabberley (2008) | Convolvulaceae. | ICBN |
| Aniselytron | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anisocampium | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Anisocarpus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anisochaeta | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anisochilus | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Anisocladella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Anisocoma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anisocomides | Rhynchodida | Lynn (2008) | . | ICZN |
| Anisocrella | Poecilosclerida | Van Soest (2002) | . | ICZN |
| Anisocycla | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Anisodontea | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Anisodus | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Anisognathus | Passeriformes | Clements (2007) | . | ICZN |
| Anisolepis | Squamata | Vitt & Caldwell (2009) | Iguanidae. | ICZN |
| Anisoloboides | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Anisolobus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Anisolpidium | Anisolpidiales | Dick (2001); Kirk et al. (2008) | Anisolpidiaceae. | ICBN |
| Anisomeles | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Anisomeria | Caryophyllales | Mabberley (2008) | Phytolaccaceae. | ICBN |
| Anisomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Anisonema | Sphenomonadales | Leedale (1967); Leedale (2000) | . | ICBN |
| Anisonyches | Echiniscoidea | Kinchin (1994) | . | ICZN |
| Anisopappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anisophyllea | Cucurbitales | Mabberley (2008) | Anisophylleaceae. | ICBN |
| Anisopoda | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Anisopogon | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anisoptera | Malvales | Mabberley (2008) | Dipterocarpaceae. | ICBN |
| Anisopus | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Anisoschizus | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Anisosciadium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Anisosepalum | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Anisotachis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anisotes | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Anisothecium | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Anisothrix | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anisotoma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Anisotome | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Ankylochrysis | Sarcinochrysidales | Andersen & Preisig (2000) | . | ICBN |
| Ankylonoton | Chloramoebales | Ettl (1978) | . | ICBN |
| Ankyropetalum | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Anna | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Annandia | Anura | Vitt & Caldwell (2009) | Dicroglossidae. | ICZN |
| Annatiara | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Anncaliia | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Annella | Alcyonacea | López-Gonz´lez & Gili (2001) | Subergorgiidae. | ICZN |
| Annelophrya | Astomatida | Lynn (2008) | . | ICZN |
| Annesijoa | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Anneslea | Ericales | Mabberley (2008) | Pentaphylacaceae. | ICBN |
| Annesorhiza | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Annickia | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Anniella | Squamata | Vitt & Caldwell (2009) | Anguidae. | ICZN |
| Annona | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Annulonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Annulopatellina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Annulopatellinidae. | ICZN |
| Anoa | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001); Grubb (2005) | Artiodactyla. Later synonym of Bubalus. | ICZN |
| Anoda | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Anodendron | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Anodiscus | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Anodonthyla | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Anodopetalum | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Anodorhynchus | Psittaciformes | Clements (2007) | . | ICZN |
| Anoeca | Anoecales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Anoectangium | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Anoectochilus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anogeissus | Myrtales | Mabberley (2008) | Combretaceae. | ICBN |
| Anogramma | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Anolis | Squamata | Vitt & Caldwell (2009) | Iguanidae. | ICZN |
| Anomacanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Anomacaulis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anomalepis | Squamata | Vitt & Caldwell (2009) | Serpentes. Anomalepididae. | ICZN |
| Anomalinella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Almaenidae. | ICZN |
| Anomalinoides | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Heterolepidae. | ICZN |
| Anomalinulla | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Gavelinellidae. | ICZN |
| Anomalocalyx | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Anomaloglossus | Anura | Vitt & Caldwell (2009) | Aromobatidae. | ICZN |
| Anomalopus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Anomalorhiza | Rhizostomeae | Kramp (1961) | . | ICZN |
| Anomalospiza | Passeriformes | Clements (2007) | . | ICZN |
| Anomalurus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Anomastraea | Scleractinia | von Marenzeller (1901); Cairns et al. (1999); Veron (2000) | Not "Anomastrea". | ICZN |
| Anomianthus | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Anomobryum | Bryales | Goffinet et al. (2009) | . | ICBN |
| Anomochilus | Squamata | Vitt & Caldwell (2009) | Serpentes. Cylindrophiidae. | ICZN |
| Anomochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anomochone | Hexactinosida | Reiswig (2002) | . | ICZN |
| Anomoclada | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anomocora | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Anomodon | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Anomoianthella | Verongida | Bergquist & Cook (2002) | . | ICZN |
| Anomopera | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Molgulidae. | ICZN |
| Anomopus | Bdelloida | Segers (2002); Segers (2007) | . | ICZN |
| Anomospermum | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Anomostachys | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Anomotassa | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Anonymomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Anopetia | Apodiformes | Clements (2007) | . | ICZN |
| Anophryoides | Philasterida | Lynn (2008) | Later synonym of Paranophrys?. | ICZN |
| Anophrys | Philasterida | Lynn (2008) | . | ICZN |
| Anoplocaryum | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Anoplodinium | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Anoplohydrus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Anoplokaros | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Anoplolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anoplophryopsis | Astomatida | Lynn (2008) | . | ICZN |
| Anoplophyra | Astomatida | Lynn (2008) | . | ICZN |
| Anops | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Anopterus | Escalloniales | Mabberley (2008) | Escalloniaceae. | ICBN |
| Anopyxis | Malpighiales | Mabberley (2008) | Rhizophoraceae. | ICBN |
| Anorrhinus | Coraciiformes | Clements (2007) | . | ICZN |
| Anotea | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Anotheca | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Anotomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Anotosaura | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Anotrichium | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Anotropis | Chloramoebales | Ettl (1978) | . | ICBN |
| Anoura | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Anourosorex | Eulipotyphla | McKenna & Bell (1997); Murphy et al. (2001) | . | ICZN |
| Anous | Charadriiformes | Clements (2007) | . | ICZN |
| Anoxybacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Anoxycalyx | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Anoxynatronum | Clostridiales | Garnova et al. (2003) | . | ICNB |
| Anoxypristis | Pristiformes | Nelson (2006) | . | ICZN |
| Anredera | Caryophyllales | Mabberley (2008) | Basellaceae. | ICBN |
| Ansellia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anser | Anseriformes | Clements (2007) | . | ICZN |
| Anseranas | Anseriformes | Clements (2007) | . | ICZN |
| Ansonia | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Antarcella | Arcellinida | Meisterfeld (2000) | Arcellina -- Arcellidae. | ICZN |
| Antarcticothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Antarctissa | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Antarctobacter | Rhodobacterales | Garrity et al. (2005) | . | ICNB |
| Antarctocolax | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Antarctolineus | Heteronemertea | Gibson (1995) | . | ICZN |
| Antarctonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Antarctosaccion | Chrysomeridales | Preisig (1995); Brown & Sorhannus (2010) | . | ICBN |
| Antarctoscyphus | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Antaresia | Squamata | Vitt & Caldwell (2009) | Serpentes. Pythonidae. | ICZN |
| Antechiniscus | Echiniscoidea | Kinchin (1994) | . | ICZN |
| Antechinomys | Dasyuromorphia | Groves (2005) | . | ICZN |
| Antechinus | Australidelphia | McKenna & Bell (1997) | . | ICZN |
| Antegibbaeum | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Anteholosticha | Urostylida | Lynn (2008) | . | ICZN |
| Antennaria | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Antennella | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Antennellopsis | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Anteremanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anthacineta | Endogenida | Lynn (2008) | . | ICZN |
| Anthaenantiopsis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anthelia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Anthelia | Alcyonacea | Bayer (1981) | Xeniidae. | ICZN |
| Anthemiphyllia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Anthemis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Anthemosoma | Piroplasmorida | Perkins et al. (2000) | . | ICZN |
| Anthenantia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Antheomorphe | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Antheopsis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthephora | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anthericopsis | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Anthericum | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Antheroporum | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Antherostele | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Antherothamnus | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Antherotoma | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Antho | Poecilosclerida | Hooper (2002) | . | ICZN |
| Anthoactis | Ceriantharia | Tiffon (1987) | . | ICZN |
| Anthobaphes | Passeriformes | Clements (2007) | . | ICZN |
| Anthobolus | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Anthocarapa | Sapindales | Mabberley (2008) | Meliaceae. | ICBN |
| Anthocephala | Apodiformes | Clements (2007) | . | ICZN |
| Anthocercis | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Anthoceros | Anthocerotales | Renzaglia et al. (2009) | . | ICBN |
| Anthochaera | Passeriformes | Clements (2007) | . | ICZN |
| Anthochlamys | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Anthochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anthochloe | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Anthochortus | Poales | Mabberley (2008) | Restionaceae. | ICBN |
| Anthocleista | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Anthocyrtidium | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Anthodiscus | Malpighiales | Mabberley (2008) | Caryocaraceae. | ICBN |
| Anthodon | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Anthogonium | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anthogorgia | Alcyonacea | Bayer (1981) | Acanthogorgiidae. | ICZN |
| Anthohebella | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Anthohydra | Limnomedusae | Bouillon et al. (2006) | . | ICZN |
| Antholoba | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthomastus | Alcyonacea | Bayer (1981) | Alcyoniidae. | ICZN |
| Anthonotha | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Anthonyella | Astomatida | Lynn (2008) | . | ICZN |
| Anthophysa | Ochromonadales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Chromulinaceae (biflagellate). | ICBN |
| Anthopleura | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthoplexaura | Alcyonacea | Bayer (1981) | Plexauridae. | ICZN |
| Anthops | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Anthopteropsis | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Anthopterus | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Anthoptilum | Pennatulacea | Williams (1995) | . | ICZN |
| Anthorhynchus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Anthornis | Passeriformes | Clements (2007) | . | ICZN |
| Anthorrhiza | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Anthosactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthoscopus | Passeriformes | Clements (2007) | . | ICZN |
| Anthosiphon | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Anthospermopsis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Anthospermum | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Anthosphaera | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | former Calyptrosphaeraceae. | ICBN |
| Anthostella | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthostema | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Anthotethya | Hadromerida | Sarà (2002) | . | ICZN |
| Anthothela | Alcyonacea | Bayer (1981) | Anthothelidae. | ICZN |
| Anthothoe | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Anthotium | Asterales | Mabberley (2008) | Goodeniaceae. | ICBN |
| Anthotroche | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Anthoxanthum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Anthracoceros | Coraciiformes | Clements (2007) | . | ICZN |
| Anthracothorax | Apodiformes | Clements (2007) | . | ICZN |
| Anthreptes | Passeriformes | Clements (2007) | . | ICZN |
| Anthriscus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Anthropoides | Gruiformes | Clements (2007) | . | ICZN |
| Anthurceolaria | Mobilida | Lynn (2008) | . | ICZN |
| Anthurium | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anthus | Passeriformes | Clements (2007) | . | ICZN |
| Anthyllis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Antiaris | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Antiaropsis | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Anticharis | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Anticlea | Liliales | Mabberley (2008) | Melanthiaceae. | ICBN |
| Anticleina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Cassidulinidae. | ICZN |
| Antidaphne | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Antidesma | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Antidorcas | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Antigonaria | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Antigonon | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Antillanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Antillia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Antillophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Antilocapra | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Antilope | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Antilophia | Passeriformes | Clements (2007) | . | ICZN |
| Antimima | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Antinoria | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Antiotrema | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Antiparactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Antipathella | Antipatharia | Opresko (2001) | . | ICZN |
| Antipathes | Antipatharia | Bo et al. (2009) | "110608". | ICZN |
| Antiphiona | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Antiphytum | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Antipia | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora. | ICZN |
| Antiponemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Antirhea | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Antirrhinum | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Antistrophe | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Antithamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Antithamnionella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Antithrixia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Antitrichia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Antizoma | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Antonia | Gentianales | Mabberley (2008) | Loganiaceae. | ICBN |
| Antonospora | Microsporida | Fries et al. (1999) | . | ICZN |
| Antopetitia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Antrocaryon | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Antrocentrum | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Antrophyum | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Antroposthia | Acoela | Faubel & Noreña (2001) | . | ICZN |
| Antrosagittifera | Acoela | Hooge & Tyler (2001) | Under confirmation. | ICZN |
| Antrozous | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Anturina | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ellipsolagenidae. | ICZN |
| Antygomonas | Cyclorhagida | Nebelsick (1990) | . | ICZN |
| Anubias | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Anumbius | Passeriformes | Clements (2007) | . | ICZN |
| Anuracanthorhynchus | Echinorhynchida | Bursey et al. (2006) | Echinorhynchidae. | ICZN |
| Anuraeopsis | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Anurofeca | Ichthyophonida | Mendoza et al. (2002) | . | ICZN |
| Anurolimnas | Gruiformes | Clements (2007) | . | ICZN |
| Anurophasis | Galliformes | Clements (2007) | . | ICZN |
| Anvillea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aongstroemia | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Aongstroemiopsis | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Aonyx | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Aoranthe | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aosa | Cornales | Mabberley (2008) | Loasaceae. | ICBN |
| Aotus | Primates | McKenna & Bell (1997) | . | ICZN |
| Aotus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Apacheria | Crossosomatales | Mabberley (2008) | Crossosomataceae. | ICBN |
| Apalanthe | Alismatales | Mabberley (2008) | Hydrocharitaceae. | ICBN |
| Apalis | Passeriformes | Clements (2007) | . | ICZN |
| Apalochlamys | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Apaloderma | Trogoniformes | Clements (2007) | . | ICZN |
| Apalone | Testudinata | Vitt & Caldwell (2009) | Trionychidae. | ICZN |
| Apalopteron | Passeriformes | Clements (2007) | . | ICZN |
| Aparallactus | Squamata | Vitt & Caldwell (2009) | Serpentes. Atractaspididae. | ICZN |
| Aparasphenodon | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Aparisthmium | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Apassalus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Apatesia | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Apatophyllum | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Apatronemertes | Heteronemertea | Gibson (1995) | . | ICZN |
| Apatzingania | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Apedinella | Pedinellales | Moestrup (2000); Sekiguchi et al. (2003) | . | ICBN |
| Apeiba | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Apera | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Apertospathula | Haptorida | Lynn (2008) | . | ICZN |
| Apetahia | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Aphaerema | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Aphanactis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aphanamixis | Sapindales | Mabberley (2008) | Meliaceae. | ICBN |
| Aphananthe | Rosales | Mabberley (2008) | Cannabaceae. | ICBN |
| Aphandra | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Aphanelytrum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aphaniotis | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Aphanipathes | Antipatharia | Opresko (2004) | . | ICZN |
| Aphanisma | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Aphanizomenon | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Aphanocalyx | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aphanocapsa | Chroococcales | Hoffmann et al. (2005) | . | ICBN |
| Aphanocarpus | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aphanocladia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Aphanodictyon | Leptomitales | Dick (2001); Kirk et al. (2008) | Leptolegniellaceae. | ICBN |
| Aphanolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Aphanomyces | Saprolegniales | Dick (2001); Kirk et al. (2008) | Leptolegniaceae. | ICBN |
| Aphanomycopsis | Leptomitales | Dick (2001); Kirk et al. (2008) | Leptolegniellaceae. | ICBN |
| Aphanopetalum | Saxifragales | Mabberley (2008) | Aphanopetalaceae. | ICBN |
| Aphanopleura | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aphanorhegma | Funariales | Goffinet et al. (2009) | . | ICBN |
| Aphanosperma | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Aphanostephus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aphanostoma | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Aphanothece | Chroococcales | Hoffmann et al. (2005) | . | ICBN |
| Aphanotriccus | Passeriformes | Clements (2007) | . | ICZN |
| Aphanotropis | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Aphanta | Gelidiales | Schneider & Wynne (2007) | . | ICBN |
| Aphantophryne | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Aphelandra | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Aphelia | Poales | Mabberley (2008) | Centrolepidaceae. | ICBN |
| Aphelidium | Aphelidida | Gromov (2000) | . | ICZN |
| Aphelocephala | Passeriformes | Clements (2007) | . | ICZN |
| Aphelocoma | Passeriformes | Clements (2007) | . | ICZN |
| Apheloecion | Acanthoecida | Leadbeater & Thomsen (2000) | . | ICZN |
| Aphloia | Crossosomatales | Mabberley (2008) | Aphloiaceae. | ICBN |
| Aphorme | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Aphragmus | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aphrastura | Passeriformes | Clements (2007) | . | ICZN |
| Aphriza | Charadriiformes | Clements (2007) | . | ICZN |
| Aphrocallistes | Hexactinosida | Reiswig (2002) | . | ICZN |
| Aphroceras | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Aphrodroma | Procellariiformes | Clements (2007) | . | ICZN |
| Aphyllanthes | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Aphyllocladus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aphyllodium | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aphyllorchis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Apiactis | Ceriantharia | Tiffon (1987) | . | ICZN |
| Apiastrum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Apicoporus | | Sparmann et al. (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. | ICBN |
| Apicystis | Neogregarinorida | Lipa & Triggiani (1996) | . | ICZN |
| Apigregarina | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Apinagia | Malpighiales | Mabberley (2008) | Podostemaceae. | ICBN |
| Apiopetalum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Apios | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Apiosoma | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Apistonema | | Kristiansen & Preisig (2001) | Domain Eucarya - Kingdom Straminipila - Phylum Ochrophyta. | ICBN |
| Apium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aplanes | Saprolegniales | Dick (2001); Kirk et al. (2008) | Later synonym of Achlya. | ICBN |
| Aplanochytrium | Thraustochytriales | Dick (2001); Kirk et al. (2008) | Thraustochytriaceae. | ICBN |
| Aplanodes | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aplanopsis | Saprolegniales | Dick (2001); Kirk et al. (2008) | Saprolegniaceae. | ICBN |
| Aplastodiscus | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Aplectrum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aplidiopsis | Aplousobranchia | Monniot & Monniot (1972); Monniot (2001) | Polyclinidae. | ICZN |
| Aplidium | Aplousobranchia | Monniot & Monniot (1972); Monniot (2001) | Polyclinidae. | ICZN |
| Aplodon | Splachnales | Goffinet et al. (2009) | . | ICBN |
| Aplodontia | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aplonis | Passeriformes | Clements (2007) | . | ICZN |
| Aplopeltura | Squamata | Vitt & Caldwell (2009); Guo et al. (2011) | Serpentes. Pareatidae. | ICZN |
| Apluda | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aplysilla | Dendroceratida | Bergquist & Cook (2002) | . | ICZN |
| Aplysina | Verongida | Bergquist & Cook (2002) | . | ICZN |
| Aplysinella | Verongida | Bergquist & Cook (2002) | . | ICZN |
| Aplysinopsis | Dictyoceratida | Cook & Bergquist (2002) | . | ICZN |
| Apoamphileptus | Pleurostomatida | Lynn (2008) | . | ICZN |
| Apoamphisiella | Sporadotrichida | Lynn (2008) | . | ICZN |
| Apobryophyllum | Haptorida | Lynn (2008) | . | ICZN |
| Apocarchesium | Peritrichida | Ji & Kusuoka (2009) | . | ICZN |
| Apocaulon | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Apochiton | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Apoclada | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Apocolpoda | Colpodida | Lynn (2008) | . | ICZN |
| Apocolpodidium | Nassulida | Lynn & Small (2000); Lynn (2008); Breiner et al. (2008) | . | ICZN |
| Apocopis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Apocoriplites | Haptorida | Oertel et al. (2008) | . | ICZN |
| Apocryptopharynx | Loxodida | Lynn (2008) | . | ICZN |
| Apocyclidium | Pleuronematida | Lynn (2008) | . | ICZN |
| Apocynum | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Apodachlya | Leptomitales | Dick (2001); Kirk et al. (2008) | Leptomitaceae. | ICBN |
| Apodachlyella | Leptomitales | Dick (2001); Kirk et al. (2008) | Apodachlyellaceae. | ICBN |
| Apodanthera | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Apodanthes | Cucurbitales | Mabberley (2008) | Apodanthaceae. | ICBN |
| Apodasmia | Poales | Mabberley (2008) | Restionaceae. | ICBN |
| Apodemus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Apodera | Arcellinida | Meisterfeld (2000) | Difflugina -- Nebelidae. | ICZN |
| Apodibius | | Kinchin (1994) | Domain Eucarya - Kingdom Animalia - Phylum Tardigrada - Class Eutardigrada. | ICZN |
| Apodicarpum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Apodinium | | Fensome et al. (1993); Skovgaard et al. (2007) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. Former Blastodiniales. | ICBN |
| Apodiophrys | Euplotida | Jiang & Song (2010) | . | ICZN |
| Apodiscus | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Apodocephala | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Apodolirion | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Apodora | Squamata | Vitt & Caldwell (2009) | Serpentes. Pythonidae. | ICZN |
| Apodostigma | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Apodytes | Icacinales | Mabberley (2008) | Icacinaceae. | ICBN |
| Apoenchelys | Haptorida | Lynn (2008) | . | ICZN |
| Apofrontonia | Peniculida | Lynn (2008) | . | ICZN |
| Apogastrostyla | | Li et al. (2010) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora - Class Spirotrichea. | ICZN |
| Apoglossocolax | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Apoglossum | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Apogromia | | Bass et al. (2009) | Domain Eucarya - Phylum Cercozoa - Class Granofilosea. | ICZN |
| Apogromia | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lagynidae. | ICZN |
| Apoikia | Ochromonadales | Kim et al. (2010) | Phylogenetically belong to Ochromonadales sensu Cavalier-Smith & Chao (2006). | ICBN |
| Apokeronopsis | Urostylida | Shao et al. (2007) | . | ICZN |
| Apolemia | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Apollonias | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Apolocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Apomarsupella | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Apometzgeria | Metzgeriales | Crandall-Stotler et al. (2009) | . | ICBN |
| Apomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aponogeton | Alismatales | Mabberley (2008) | Aponogetonaceae. | ICBN |
| Apophlaea | Hildenbrandiales | Schneider & Wynne (2007) | . | ICBN |
| Apophyllum | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Apoplanesia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Apopyros | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Apororhynchus | Apororhynchida | Amin (1985) | . | ICZN |
| Aporosa | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Aporostylis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aporrhiza | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Aposeris | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Apospathidium | Haptorida | Lynn (2008) | . | ICZN |
| Apospironympha | Trichonymphida | Cepicka et al. (2010) | . | ICZN |
| Apostasia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Apostates | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Apostolepis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Apotomanthus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Apotrachelocerca | Protostomatida | Xu et al. (2011) | Originally classified in the order Trachelocercida. | ICZN |
| Apotreubia | Treubiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Apourosomoida | Sporadotrichida | Lynn (2008) | . | ICZN |
| Apourostylopsis | Urostylida | Song et al. (2011) | . | ICZN |
| Appendicula | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Appendicularia | Appendicularia | Fenaux (1998) | . | ICZN |
| Appendicularia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Appertiella | Alismatales | Mabberley (2008) | Hydrocharitaceae. | ICBN |
| Aprasia | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Apristurus | Carcharhiniformes | Nelson (2006) | . | ICZN |
| Aprosmictus | Psittaciformes | Clements (2007) | . | ICZN |
| Aproteles | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Apsiktrata | Prostomatida | Lynn (2008) | . | ICZN |
| Apsteinia | Peridiniales | Fensome et al. (1993) | . | ICBN |
| Aptandra | Santalales | Mabberley (2008) | Olacaceae. | ICBN |
| Aptenodytes | Sphenisciformes | Clements (2007) | . | ICZN |
| Apteria | Dioscoreales | Mabberley (2008) | Burmanniaceae. | ICBN |
| Apterosperma | Ericales | Mabberley (2008) | Theaceae. | ICBN |
| Apterygodon | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Apteryx | Struthioniformes | Clements (2007) | . | ICZN |
| Aptosimum | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Aptychella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aptychopsis | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Aptychotrema | Rajiformes | Nelson (2006) | . | ICZN |
| Apuleia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Apurimacia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Apus | Apodiformes | Clements (2007) | . | ICZN |
| Apusomonas | Apusomonadida | Cavalier-Smith et al. (2008) | . | ICZN |
| Aquabacter | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Aquabacterium | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Aquadulcum | | Fensome et al. (1993) | Domain Eucarya - Phylum Dinozoa - Class Dinophyceae - Subclass Peridiniphycidae. Holocene. | ICBN |
| Aqualinderella | Rhipidiales | Dick (2001); Kirk et al. (2008) | Rhipidiaceae. | ICBN |
| Aquamicrobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Aquaspirillum | Neisseriales | Garrity et al. (2005) | . | ICNB |
| Aquicella | Rickettsiella | Santos et al. (2003) | . | ICNB |
| Aquifex | Aquificales | Garrity et al. (2005) | . | ICNB |
| Aquiflexum | Cytophagales | Brettar et al. (2004); Ludwig et al. (2011) | . | ICNB |
| Aquila | Falconiformes | Clements (2007) | . | ICZN |
| Aquilaria | Malvales | Mabberley (2008) | Thymelaeaceae. | ICBN |
| Aquilegia | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Aquimarina | Flavobacteriales | Nedashkovskaya et al. (2005) | . | ICNB |
| Aquimonas | Xanthomonadales | Saha et al. (2005) | . | ICNB |
| Aquincola | Burkholderiales | Lechner et al. (2007) | . | ICNB |
| Aquipuribacter | Micrococcales | Tóth et al. (2012); Ludwig et al. (2012) | Intrasporangiaceae. | ICNB |
| Aquisalibacillus | Bacillales | Márquez et al. (2008) | . | ICNB |
| Aquisalimonas | Chromatiales | Márquez et al. (2007) | . | ICNB |
| Aquisphaera | Planctomycetales | Bondoso et al. (2011) | . | ICNB |
| Aquitalea | Neisseriales | Lau et al. (2006) | . | ICNB |
| Aquixalus | Anura | Vitt & Caldwell (2009) | Rhacophoridae. | ICZN |
| Ara | Psittaciformes | Clements (2007) | . | ICZN |
| Arabescula | | Pisera & Lévi (2002) | Domain Eucarya - Kingdom Animalia - Phylum Porifera - Class Demospongiae (lithistids). | ICZN |
| Arabidella | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Arabidopsis | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Arabis | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aracamunia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arachis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Arachnactis | Ceriantharia | Tiffon (1987) | . | ICZN |
| Arachnanthus | Ceriantharia | Tiffon (1987) | . | ICZN |
| Arachnidiopsis | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora. Nomen dubium. | ICZN |
| Arachniodes | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Arachniopsis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Arachnis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arachnitis | Liliales | Mabberley (2008) | Corsiaceae. | ICBN |
| Arachnochloris | Mischococcales | Ettl (1978) | . | ICBN |
| Arachnocorys | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Arachnocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Arachnodinella | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Arachnophyllum | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Arachnothera | Passeriformes | Clements (2007) | . | ICZN |
| Arachnula | Aconchulinida | Bass et al. (2009) | . | ICZN |
| Araeococcus | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Arafoe | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aragoa | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Araiospora | Rhipidiales | Dick (2001); Kirk et al. (2008) | Rhipidiaceae. | ICBN |
| Aralia | Apiales | Mabberley (2008) | Araliaceae. | ICBN |
| Aralidium | Apiales | Mabberley (2008) | Torricelliaceae. | ICBN |
| Aramides | Gruiformes | Clements (2007) | . | ICZN |
| Aramidopsis | Gruiformes | Clements (2007) | . | ICZN |
| Aramus | Gruiformes | Clements (2007) | . | ICZN |
| Araneum | Phlebobranchia | Monniot (2001) | Cionidae. | ICZN |
| Arapatiella | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aratinga | Psittaciformes | Clements (2007) | . | ICZN |
| Aratitiyopea | Poales | Mabberley (2008) | Xyridaceae. | ICBN |
| Araucaria | Araucariales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Araujia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Arbelaezaster | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arberella | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arbor | Astrorhizida | Kaminski (2000) | Baculellidae. | ICZN |
| Arborammina | Astrorhizida | Kaminski (2000) | Arboramminidae, Astrorhizacea. | ICZN |
| Arborimus | Rodentia | Musser & Carleton (2005) | . | ICZN |
| Arborocystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Arborophila | Galliformes | Clements (2007) | . | ICZN |
| Arbusculohypopterygium | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Arbutus | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Arcanator | Passeriformes | Clements (2007) | . | ICZN |
| Arcangelisia | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Arcanobacterium | Actinomycetales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Arcella | Arcellinida | Meisterfeld (2000) | Arcellina -- Arcellidae. | ICZN |
| Arceuthobium | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Archactinoposthia | Acoela | Faubel & Noreña (2001) | Also spelled as "Proactinoposthia" in the original description. | ICZN |
| Archaeoglobus | Archaeoglobales | Garrity et al. (2005) | . | ICNB |
| Archaeopsis | Glaucocystales | Kies & Kremer (1986) | Nomen nudum. | ICBN |
| Archaeosphaerodiniopsis | | Fensome et al. (1993) | Domain Eucarya - Phylum Dinozoa - Class Dinophyceae - Subclass Peridiniphycidae. | ICBN |
| Archaeperidinium | Peridiniales | Fensome et al. (1993) | . | ICBN |
| Archaias | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Soritidae. | ICZN |
| Archakebia | Ranunculales | Mabberley (2008) | Lardizabalaceae. | ICBN |
| Archangelopsis | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Archangium | Myxococcales | Garrity et al. (2005) | . | ICNB |
| Archaphanostoma | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Archboldia | Passeriformes | Clements (2007) | . | ICZN |
| Archboldiodendron | Ericales | Mabberley (2008) | Pentaphylacaceae. | ICBN |
| Archboldomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Archechiniscus | Arthrotardigrada | Kinchin (1994) | . | ICZN |
| Archeophylla | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Archerella | Tectofilosida | Meisterfeld (2000); Cavalier-Smith & Chao (2003) | Amphitremidae. | ICZN |
| Archeria | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Archestenogramma | Gigartinales | Schneider et al. (2011) | . | ICBN |
| Archeterokrohnia | Phragmophora | Casanova (1985); Bieri (1991) | Heterokrohniidae. Now checking. | ICZN |
| Archiascidia | Aplousobranchia | Monniot & Monniot (1972); Kott (1998); Monniot (2001) | Junior synonym of Pycnoclavella. | ICZN |
| Archiatriplex | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Archibaccharis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Archiboehmeria | Rosales | Mabberley (2008) | Urticaceae. | ICBN |
| Archidendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Archidendropsis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Archidistoma | Aplousobranchia | Monniot & Monniot (1972); Kott (1998); Monniot (2001) | Polycitoridae. | ICZN |
| Archidium | Archidiales | Goffinet et al. (2009) | . | ICBN |
| Archilejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Archilochus | Apodiformes | Clements (2007) | . | ICZN |
| Archimerismus | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hormosinidae. | ICZN |
| Archinassula | Nassulida | Lynn (2008) | . | ICZN |
| Archirhodomyrtus | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Architricha | Sporadotrichida | Lynn (2008) | . | ICZN |
| Archivea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Archocelis | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Archohelia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Archontophoenix | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Archytaea | Malpighiales | Mabberley (2008) | Bonnetiaceae. | ICBN |
| Arcicella | Cytophagales | Nikitin et al. (2004); Ludwig et al. (2011) | . | ICNB |
| Arcoa | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Arcobacter | Campylobacterales | Garrity et al. (2005) | . | ICNB |
| Arcosoma | Exogenida | Lynn (2008) | . | ICZN |
| Arctagrostis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arctanthemum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arctapodema | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Arcteranthis | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Arctictis | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Arctium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arctoa | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Arctocebus | Primates | McKenna & Bell (1997) | . | ICZN |
| Arctocephalus | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Arctogalidia | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Arctogeron | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arctomecon | Ranunculales | Mabberley (2008) | Papaveraceae. | ICBN |
| Arctonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Arctonyx | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Arctophila | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arctopus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Arctoscyphus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Arctostaphylos | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Arctotheca | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arctotis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arctottonia | Piperales | Mabberley (2008) | Piperaceae. | ICBN |
| Arcuatopterus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Arcuospathidium | Haptorida | Lynn (2008) | . | ICZN |
| Arcyna | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arcyodes | Trichiales | Yamamoto (1998) | . | ICBN |
| Arcyosperma | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Arcyria | Trichiales | Yamamoto (1998) | . | ICBN |
| Arcyriatella | Trichiales | Yamamoto (1998) | . | ICBN |
| Arcytophyllum | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Ardea | Ciconiiformes | Clements (2007) | . | ICZN |
| Ardeirhynchus | Polymorphida | Dimitrova & Georgiev (1994) | Polymorphidae. | ICZN |
| Ardeola | Ciconiiformes | Clements (2007) | . | ICZN |
| Ardeotis | Gruiformes | Clements (2007) | . | ICZN |
| Ardisia | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Ardisiandra | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Ardissonula | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Ardops | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Ardreanema | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Areca | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Aremonia | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Arenaria | Charadriiformes | Clements (2007) | . | ICZN |
| Arenaria | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Arenga | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Arenibacter | Flavobacteriales | Garrity et al. (2005) | . | ICNB |
| Arenicella | | Romanenko et al. (2010) | . | ICNB |
| Arenifera | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Arenimonas | Xanthomonadales | Kwon et al. (2007) | . | ICNB |
| Arenomeandrospira | Lituolida | Kaminski (2004) | Ammovertellininae, Ammodiscacea. | ICZN |
| Arenonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Arenoparrella | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Trochamminidae. | ICZN |
| Arenophryne | Anura | Vitt & Caldwell (2009) | Myobatrachidae. | ICZN |
| Arenosclera | Haplosclerida | Desqueyroux-Faúndez & Valentine (2002) | . | ICZN |
| Arenoturrispirillina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ammodiscidae. | ICZN |
| Arenotus | Chaetonotida | Balsamo et al. (2009) | . | ICZN |
| Arequinus | Anura | Vitt & Caldwell (2009) | Hyperoliidae. | ICZN |
| Areschougia | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Arethusa | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arfeuillea | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Argania | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Argemone | Ranunculales | Mabberley (2008) | Papaveraceae. | ICBN |
| Argenteohyla | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Argentipallium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argillotuba | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Allogromiidae. | ICZN |
| Argocoffeopsis | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Argomuellera | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Argonemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Argophyllum | Asterales | Mabberley (2008) | Argophyllaceae. | ICBN |
| Argostemma | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Argusianus | Galliformes | Clements (2007) | . | ICZN |
| Argylia | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Argynnia | Arcellinida | Meisterfeld (2000) | Difflugina -- Nebelidae. | ICZN |
| Argyranthemum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argyreia | Solanales | Mabberley (2008) | Convolvulaceae. | ICBN |
| Argyrochosma | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Argyrocytisus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Argyrodendron | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Argyroderma | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Argyrogena | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Argyroglottis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argyrolobium | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Argyrotegium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argyrovernonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argyroxiphium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Argythamnia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Arhodomonas | Chromatiales | Garrity et al. (2005) | . | ICNB |
| Arhynchobatis | Rajiformes | Nelson (2006) | . | ICZN |
| Arhynchonemertes | Arhynchonemertea | Gibson (1995); Chernyshev (1995) | . | ICZN |
| Arhythmorhynchus | Polymorphida | Amin (1985) | . | ICZN |
| Arida | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aridarum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Arielulus | Chiroptera | Simmons (2005) | . | ICZN |
| Arillastrum | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Ariocarpus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Ariopsis | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Aripuana | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Arisaema | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Arisarum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Aristea | Asparagales | Mabberley (2008) | Iridaceae. | ICBN |
| Aristeguietia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aristelliger | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Aristerostoma | Cyrtolophosidida | Lynn (2008) | . | ICZN |
| Aristida | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Aristocapsa | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Aristogeitonia | Malpighiales | Mabberley (2008) | Picrodendraceae. | ICBN |
| Aristolochia | Piperales | Mabberley (2008) | Aristolochiaceae. | ICBN |
| Aristoptilon | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Aristotelia | Oxalidales | Mabberley (2008) | Elaeocarpaceae. | ICBN |
| Ariteus | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Arizona | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Arjona | Santalales | Mabberley (2008) | Schoepfiaceae. | ICBN |
| Armadillogorgia | Alcyonacea | Bayer (1981) | Primnoidae. | ICZN |
| Armatimonas | Armatimonadales | Tamaki et al. (2011) | . | ICNB |
| Armatocereus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Armatodifflugia | Arcellinida | Snegovaya & Alekperov (2005) | Difflugiidae. | ICZN |
| Armatospathula | Haptorida | Lynn (2008) | . | ICZN |
| Armaueria | Pelagica | Gibson (1995) | . | ICZN |
| Armeria | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Armichona | Cryptogemmida | Lynn (2008) | . | ICZN |
| Armodorum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Armoracia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Armorhydra | Limnomedusae | Bouillon et al. (2006) | . | ICZN |
| Armorloricus | Nanaloricida | Heiner & Kristensen (2009) | . | ICZN |
| Arnaldoa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arnbackia | Stolidobranchia | Monniot & Monniot (1972) | Styelidae. | ICZN |
| Arnebia | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Arnellia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Arnhemia | Malvales | Mabberley (2008) | Thymelaeaceae. | ICBN |
| Arnica | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arnicastrum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arnicratea | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Arnocrinum | Asparagales | Mabberley (2008) | Hemerocallidaceae. | ICBN |
| Arnoglossum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arnoseris | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aromobates | Anura | Vitt & Caldwell (2009) | Aromobatidae. | ICZN |
| Aronia | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Arophyton | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Arpophyllum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arrabidaea | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Arracacia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Arremon | Passeriformes | Clements (2007) | . | ICZN |
| Arremonops | Passeriformes | Clements (2007) | . | ICZN |
| Arrhenatherum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arrhenechthites | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arrhyton | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Arrojadoa | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Arrojadocharis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arrowsmithia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arsenicicoccus | Micrococcales | Collins et al. (2004); Ludwig et al. (2012) | . | ICNB |
| Arsenophonus | Enterobacteriales | Garrity et al. (2005) | . | ICNB |
| Arses | Passeriformes | Clements (2007) | . | ICZN |
| Artabotrys | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Artamella | Passeriformes | Clements (2007) | . | ICZN |
| Artamus | Passeriformes | Clements (2007) | . | ICZN |
| Artanema | Lamiales | Mabberley (2008) | Linderniaceae. | ICBN |
| Artedia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Artemidactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Artemisia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Artemisiella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Artemisina | Poecilosclerida | Hooper (2002) | . | ICZN |
| Artemisiopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Arthraerva | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Arthragrostis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arthraxon | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arthrobacter | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Arthrobotrya | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Arthrocardia | Corallinales | Schneider & Wynne (2007) | . | ICBN |
| Arthrocereus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Arthrochilus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Arthrochrysis | Ochromonadales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Dinobryaceae (biflagellate). | ICBN |
| Arthroclianthus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Arthrocnemum | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Arthrocormus | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Arthrogloea | | Kristiansen & Preisig (2001) | Domain Eucarya - Kingdom Straminipila - Phylum Ochrophyta. | ICBN |
| Arthrogorgia | Alcyonacea | Bayer (1981) | Primnoidae. | ICZN |
| Arthroleptella | Anura | Vitt & Caldwell (2009) | Pyxicephalidae. | ICZN |
| Arthroleptis | Anura | Vitt & Caldwell (2009) | Arthroleptidae. | ICZN |
| Arthromeris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Arthronema | Pseudanabaenales | Hoffmann et al. (2005) | . | ICBN |
| Arthrophyllum | Apiales | Mabberley (2008) | Araliaceae. | ICBN |
| Arthrophytum | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Arthropodium | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Arthropogon | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arthropteris | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Arthropyxis | Ochromonadales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Dinobryaceae (biflagellate). | ICBN |
| Arthrosaura | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Arthrospira | Oscillatoriales | Hoffmann et al. (2005) | . | ICBN |
| Arthrostemma | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Arthrostylidium | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arthrostylis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Artia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Artibeus | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Articulina | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Artocarpus | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Artorima | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Aruncus | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Arundina | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Arundinaria | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arundinella | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arundinicola | Passeriformes | Clements (2007) | . | ICZN |
| Arundinula | Ichthyophonida | Kirk et al. (2008) | Eccrinales in mycology. | ICZN |
| Arundo | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arundoclaytonia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Arvicanthis | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Arvicola | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Arytera | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Asaccharobacter | Coriobacteriales | Minamida et al. (2008); Ludwig et al. (2012) | . | ICNB |
| Asaccus | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Asaemia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asaia | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Asajirus | Aspiraculata | Kott (1989) | Replacement name for Hexacrobylus. | ICZN |
| Asanoa | Micromonosporales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Asanonella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Epistomariidae. | ICZN |
| Asanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asarina | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Asarotammina | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Trochamminidae. | ICZN |
| Asarum | Piperales | Mabberley (2008) | Aristolochiaceae. | ICBN |
| Asbestopluma | Poecilosclerida | Hajdu & Vacelet (2002) | . | ICZN |
| Ascaltis | Clathrinida | Borojevic et al. (2002) | . | ICZN |
| Ascampbelliella | Tintinnida | Lynn (2008) | . | ICZN |
| Ascandra | Clathrinida | Borojevic et al. (2002) | . | ICZN |
| Ascaphus | Anura | Vitt & Caldwell (2009) | Leiopelmatidae. | ICZN |
| Ascarina | Chloranthales | Mabberley (2008) | Chloranthaceae. | ICBN |
| Asceptrulum | Hexactinosida | Duplessis & Reiswig (2004) | . | ICZN |
| Aschemonella | Psamminida | Gooday & Tendal (2000) | . | ICZN |
| Aschersoniodoxa | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aschisma | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Aschistanthera | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Asciadium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Asciaporrecta | Ploima | De Smet (2006); Segers (2007) | . | ICZN |
| Ascidia | Phlebobranchia | Monniot & Monniot (1972); Monniot (2001) | Ascidiidae. | ICZN |
| Ascidiella | Phlebobranchia | Monniot & Monniot (1972); Monniot (2001) | Ascidiidae. | ICZN |
| Ascidiogyne | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ascidiota | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Asclepias | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Ascobius | Heterotrichida | Lynn (2008) | . | ICZN |
| Ascocentrum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ascocephalus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Ascochilopsis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ascochilus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ascoglena | Euglenales | Leedale (1967); Leedale (2000) | . | ICBN |
| Ascoglossum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Ascogregarina | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Ascolepis | Alcyonacea | Bayer (1981) | Primnoidae. | ICZN |
| Ascolepis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Ascomorpha | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Ascomorphella | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Asconema | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Ascoparia | Nemertodermatida | Sterrer (1998) | . | ICZN |
| Ascopera | Stolidobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Molgula. | ICZN |
| Ascopholis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Ascophrys | Pilisuctorida | Lynn (2008) | . | ICZN |
| Ascotheca | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Ascute | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Ascyssa | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Asellia | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Aselliscus | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Asemnantha | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Asepalum | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Ashbrookia | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Placentulinidae. | ICZN |
| Ashbyia | Passeriformes | Clements (2007) | . | ICZN |
| Ashtonia | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Asimina | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Asio | Strigiformes | Clements (2007) | . | ICZN |
| Asiocolotes | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Askenasia | Cyclotrichiida | Lynn (2008) | . | ICZN |
| Asketanthera | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Askidiosperma | Poales | Mabberley (2008) | Restionaceae. | ICBN |
| Askoella | Pilisuctorida | Lynn (2008) | . | ICZN |
| Askonides | Aplousobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Leptoclinides. | ICZN |
| Aspalathus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Asparagopsis | Bonnemaisoniales | Schneider & Wynne (2007) | . | ICBN |
| Asparagus | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Aspasia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aspatha | Coraciiformes | Clements (2007) | . | ICZN |
| Aspelta | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Asperaxis | Alcyonacea | Alderslade (2006) | Melithaeidae. | ICZN |
| Aspersentis | Echinorhynchida | Amin (1985) | . | ICZN |
| Asperuginoides | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Asperugo | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Asperula | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Asphodeline | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Asphodelus | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Aspicarpa | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Aspidelaps | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Aspidiophorus | Chaetonotida | Balsamo et al. (2009); Hummon & Todaro (2010) | . | ICZN |
| Aspidisca | Euplotida | Lynn (2008) | . | ICZN |
| Aspidistra | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Aspidites | Squamata | Vitt & Caldwell (2009) | Serpentes. Pythonidae. | ICZN |
| Aspidocarya | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Aspidoglossum | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aspidogyne | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aspidomorphus | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Aspidonepsis | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aspidopterys | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Aspidoscelis | Squamata | Vitt & Caldwell (2009) | Teiidae. | ICZN |
| Aspidoscopulia | Hexactinosida | Reiswig (2002) | . | ICZN |
| Aspidosperma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aspidostemon | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Aspidotis | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Aspidura | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Asplanchna | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Asplanchnopus | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Aspleniopsis | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Asplenium | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Asplundia | Pandanales | Mabberley (2008) | Cyclanthaceae. | ICBN |
| Asplundianthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aspromonas | Xanthomonadales | Jin et al. (2007) | . | ICNB |
| Assa | Anura | Vitt & Caldwell (2009) | Myobatrachidae. | ICZN |
| Assilina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nummulitidae. | ICZN |
| Assulina | Euglyphida | Meisterfeld (2000) | . | ICZN |
| Asta | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Astacolus | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Vaginulinidae. | ICZN |
| Astartea | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Astasia | | Leedale (1967); Leedale (2000); Busse & Preisfeld (2003) | Domain Eucarya - Phylum Euglenozoa - Class Euglenophyceae (closely related to Rhabdomonadales). | ICBN |
| Astelia | Asparagales | Mabberley (2008) | Asteliaceae. | ICBN |
| Astephanus | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Aster | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asteranthe | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Asteranthera | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Asteranthos | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Asterella | Marchantiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Asteridea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asterifer | Exogenida | Lynn (2008) | . | ICZN |
| Asterigerina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Asterigerinidae. | ICZN |
| Asterigerinata | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Asterigerinatidae. | ICZN |
| Asteriopathes | Antipatharia | Opresko (2004) | . | ICZN |
| Asteriscium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Asteriscus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asterocapsa | Chroococcales | Hoffmann et al. (2005) | . | ICBN |
| Asterocarpa | Stolidobranchia | Monniot & Monniot (1972) | Styelidae. | ICZN |
| Asterochloris | Trebouxiales | Skaloud & Peksa (2010) | . | ICBN |
| Asterocolax | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Asterodinium | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Asterogloea | Mischococcales | Ettl (1978) | . | ICBN |
| Asterogyne | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Asterohyptis | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Asterolasia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Asteroleplasma | Anaeroplasmatales | Garrity et al. (2005) | . | ICNB |
| Asteromenia | Rhodymeniales | Schneider & Wynne (2007) | . | ICBN |
| Asteromyrtus | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Asteronemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Asteroparatrochammina | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Remaneicidae. | ICZN |
| Asteropeia | Caryophyllales | Mabberley (2008) | Asteropeiaceae. | ICBN |
| Asterophora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Asterophrys | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Asteropsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asteropus | Astrophorida | Uriz (2002) | . | ICZN |
| Asteropyrum | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Asterorotalia | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Rotaliidae. | ICZN |
| Asterosiphon | | Rieth (1980); Maistro et al. (2009) | Domain Eucarya - Kingdom Straminipila - Phylum Ochrophyta - Class Xanthophyceae. | ICBN |
| Asterosmilia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Asterospicularia | Alcyonacea | Bayer (1981); Verseveldt & Bayer (1988) | Alcyoniidae. | ICZN |
| Asterostemma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Asterostigma | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Asterothamnus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Asterotrichion | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Asterotrochammina | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Remaneicidae. | ICZN |
| Asthenes | Passeriformes | Clements (2007) | . | ICZN |
| Asthenochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Asthenodipsas | Squamata | Guo et al. (2011) | Serpentes. Pareatidae. | ICZN |
| Astianthus | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Asticcacaulis | Caulobacterales | Garrity et al. (2005) | . | ICNB |
| Astiella | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Astilbe | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Astilboides | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Astiria | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Astomaea | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Astomiopsis | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Astonia | Alismatales | Mabberley (2008) | Alismataceae. | ICBN |
| Astracantha | Phaeocystida | Takahashi & Anderson (2000) | . | ICZN |
| Astragalus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Astrammina | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Saccamminidae. | ICZN |
| Astrangia | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Astranthium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Astrantia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Astrapia | Passeriformes | Clements (2007) | . | ICZN |
| Astrebla | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Astreopora | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Astreosmilia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Astreptonema | Ichthyophonida | Cafaro (2005); Kirk et al. (2008) | Eccrinales in mycology. | ICZN |
| Astridia | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Astripomoea | Solanales | Mabberley (2008) | Convolvulaceae. | ICBN |
| Astrocalyx | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Astrocaryum | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Astrocasia | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Astrochelys | Testudinata | Vitt & Caldwell (2009) | Testudinidae. | ICZN |
| Astrococcus | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Astrocystella | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Astrodaucus | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Astrogorgia | Alcyonacea | Bayer (1981) | Plexauridae. | ICZN |
| Astrohydra | Limnomedusae | Bouillon et al. (2006) | . | ICZN |
| Astroides | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Astrolabia | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Astrolepis | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Astrolithium | Symphyacanthida | Febvre et al. (2000) | . | ICZN |
| Astroloba | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Astroloma | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Astrolonche | Symphyacanthida | Febvre et al. (2000) | . | ICZN |
| Astronia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Astronidium | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Astronium | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Astrononion | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nonionidae. | ICZN |
| Astronympha | Cristamonadida | Cepicka et al. (2010) | . | ICZN |
| Astrophrya | Endogenida | Lynn (2008) | . | ICZN |
| Astrophytum | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Astrorhiza | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Astrorhizidae. | ICZN |
| Astrorhizinulla | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bathysiphonidae. | ICZN |
| Astrorhizoides | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Astrorhizidae. | ICZN |
| Astrosclera | Agelasida | Vacelet (2002) | . | ICZN |
| Astrosiga | Craspedida | Leadbeater & Thomsen (2000) | . | ICZN |
| Astrosphaera | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Astrothalamus | Rosales | Mabberley (2008) | Urticaceae. | ICBN |
| Astrotia | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Astrotricha | Apiales | Mabberley (2008) | Araliaceae. | ICBN |
| Astrotrichilia | Sapindales | Mabberley (2008) | Meliaceae. | ICBN |
| Astrotylus | Hadromerida | Plotkin & Janussen (2007) | . | ICZN |
| Astya | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Astydamia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Astylosternus | Anura | Vitt & Caldwell (2009) | Arthroleptidae. | ICZN |
| Astylozoon | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Asymblepharus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Asymbolus | Carcharhiniformes | Nelson (2006) | . | ICZN |
| Asyncoryne | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Asyneuma | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Asystasia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Atactorhynchus | Neoechinorhynchida | Amin (1985) | . | ICZN |
| Ataenidia | Zingiberales | Mabberley (2008) | Marantaceae. | ICBN |
| Atalantia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Atalaya | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Atalotriccus | Passeriformes | Clements (2007) | . | ICZN |
| Atamisquea | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Atapozoa | Aplousobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Sigillina. | ICZN |
| Ataxiodinium | Gonyaulacales | Fensome et al. (1993) | Holocene. | ICBN |
| Atelanthera | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Ateleia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Atelepithites | Dysteriida | Lynn (2008) | . | ICZN |
| Atelerix | Erinaceomorpha | Hutterer (2005) | . | ICZN |
| Ateles | Primates | McKenna & Bell (1997) | . | ICZN |
| Atelocynus | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Atelodinium | Syndinida | Fensome et al. (1993) | . | ICZN |
| Atelognathus | Anura | Vitt & Caldwell (2009) | Ceratophryidae. | ICZN |
| Atelomycterus | Carcharhiniformes | Nelson (2006) | . | ICZN |
| Atelopus | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Atelornis | Coraciiformes | Clements (2007) | . | ICZN |
| Atergia | Hadromerida | Boury-Esnault (2002) | . | ICZN |
| Ateuchosaurus | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Athalamia | Marchantiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Athamanta | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Athanasia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Athenaea | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Athene | Strigiformes | Clements (2007) | . | ICZN |
| Atherandra | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Atheris | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Atherolepis | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Atherosperma | Laurales | Mabberley (2008) | Atherospermataceae. | ICBN |
| Athertonia | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Atherurus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Athorybia | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Athrixia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Athroisma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Athroostachys | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Athrotaxis | Cupressales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Athyana | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Athyrium | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Athysanus | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Atilax | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Atkinsiella | | Dick (2001); Kirk et al. (2008); Muraosa et al. (2009) | Domain Eucarya - Kingdom Straminipila - Phylum Oomycota - Class Oomycetes - Subclass Saprolegniomycetidae. | ICBN |
| Atkinsonia | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Atlanthemum | Malvales | Mabberley (2008) | Cistaceae. | ICBN |
| Atlanticellodinium | Syndinida | Fensome et al. (1993) | . | ICZN |
| Atlantiella | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Trochamminidae. | ICZN |
| Atlantisella | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Atlantisia | Gruiformes | Clements (2007) | . | ICZN |
| Atlantoraja | Rajiformes | Nelson (2006) | . | ICZN |
| Atlantoxerus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Atlapetes | Passeriformes | Clements (2007) | . | ICZN |
| Atolla | Coronatae | Kramp (1961) | . | ICZN |
| Atomostigma | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Atopobacter | Lactobacillales | Garrity et al. (2005) | . | ICNB |
| Atopobium | Coriobacteriales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Atopochilodon | Chlamydodontida | Lynn (2008) | . | ICZN |
| Atopococcus | Lactobacillales | Collins et al. (2005) | . | ICNB |
| Atopodinium | Odontostomatida | Lynn (2008) | . | ICZN |
| Atopogaster | Aplousobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Synoicum. | ICZN |
| Atopophrynus | Anura | Vitt & Caldwell (2009) | Brachycephalidae. | ICZN |
| Atopostipes | Lactobacillales | Cotta et al. (2004) | . | ICNB |
| Atorella | Coronatae | Kramp (1961) | . | ICZN |
| Atoxoplasma | Eucoccidiorida | Perkins et al. (2000); Barta et al. (2005) | Junior synonym of Isospora. | ICZN |
| Atractantha | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Atractaspis | Squamata | Vitt & Caldwell (2009) | Serpentes. Atractaspididae. | ICZN |
| Atractocarpus | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Atractogyne | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Atractophora | Bonnemaisoniales | Schneider & Wynne (2007) | . | ICBN |
| Atractos | Stichotrichida | Lynn (2008) | . | ICZN |
| Atractus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Atractylis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Atractylocarpus | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Atractylodes | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Atraktochrysis | Ochromonadales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Chromulinaceae (biflagellate). | ICBN |
| Atraktomonas | Sphenomonadales | Leedale (1967); Leedale (2000) | . | ICBN |
| Atraphaxis | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Atretium | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Atretochoana | Gymnophiona | Vitt & Caldwell (2009) | Typhlonectidae. | ICZN |
| Atrichantha | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Atrichopsis | Polytrichales | Goffinet et al. (2009) | . | ICBN |
| Atrichornis | Passeriformes | Clements (2007) | . | ICZN |
| Atrichoseris | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Atrichum | Polytrichales | Goffinet et al. (2009) | . | ICBN |
| Atriofolliculina | Heterotrichida | Lynn (2008) | nomen nudum. | ICZN |
| Atriofronta | Acoela | Dörjes (1968); Faubel & Noreña (2001) | . | ICZN |
| Atriolum | Aplousobranchia | Kott (1998) | Didemnidae. | ICZN |
| Atrionemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Atriplex | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Atrochus | Collothecaceae | Segers (2002); Segers (2007) | . | ICZN |
| Atropa | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Atropanthe | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Atropoides | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Atroxima | Fabales | Mabberley (2008) | Polygalaceae. | ICBN |
| Attagis | Charadriiformes | Clements (2007) | . | ICZN |
| Attalea | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Atthis | Apodiformes | Clements (2007) | . | ICZN |
| Atticora | Passeriformes | Clements (2007) | . | ICZN |
| Attila | Passeriformes | Clements (2007) | . | ICZN |
| Atubaria | Cephalodiscida | Benito (1982); Halanych (1996) | Probably a junior synonym of Cephalodiscus. | ICZN |
| Atuna | Malpighiales | Mabberley (2008) | Chrysobalanaceae. | ICBN |
| Atyponemertes | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Aubletiana | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Aubregrinia | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Aubrevillea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Aubria | Anura | Vitt & Caldwell (2009) | Pyxicephalidae. | ICZN |
| Aubrieta | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Aucoumea | Sapindales | Mabberley (2008) | Burseraceae. | ICBN |
| Aucuba | Garryales | Mabberley (2008) | Garryaceae. | ICBN |
| Audouinella | Acrochaetiales | Schneider & Wynne (2007) | . | ICBN |
| Audouinia | Bruniales | Mabberley (2008) | Bruniaceae. | ICBN |
| Auerbachia | Bivalvulida | Lom & Dyková (2006) | . | ICZN |
| Auerodendron | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Augastes | Apodiformes | Clements (2007) | . | ICZN |
| Augea | Zygophyllales | Mabberley (2008) | Zygophyllaceae. | ICBN |
| Augophyllum | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Augouardia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Augusta | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aulacantha | Phaeocystida | Takahashi & Anderson (2000) | . | ICZN |
| Aulacocalyx | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Aulacoctena | Cydippida | Harbison & Madin (1982) | Probably not "Aulococtena". | ICZN |
| Aulacomnium | Aulacomniales | Stech & Frey (2008); Goffinet et al. (2009) | . | ICBN |
| Aulacopilum | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Aulacorhynchus | Piciformes | Clements (2007) | . | ICZN |
| Aulacospermum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Aulactinia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Aulakochloris | Mischococcales | Ettl (1978) | . | ICBN |
| Aulandra | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Aularia | Phaeosphaerida | Takahashi & Anderson (2000) | . | ICZN |
| Aulax | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Auletta | Halichondrida | Alvarez & Hooper (2002) | . | ICZN |
| Auliscomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Aulocalyx | Aulocalycoida | Reiswig (2002) | . | ICZN |
| Aulocyathus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Aulofolliculina | Heterotrichida | Lynn (2008) | . | ICZN |
| Aulohalaelurus | Carcharhiniformes | Nelson (2006) | . | ICZN |
| Aulomonas | Craspedida | Leadbeater & Thomsen (2000) | . | ICZN |
| Aulonemia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Auloplax | Hexactinosida | Reiswig (2002) | . | ICZN |
| Aulosaccus | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Aulosepalum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Aulosira | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Aulosphaera | Phaeosphaerida | Takahashi & Anderson (2000) | . | ICZN |
| Aulospongus | Poecilosclerida | Hooper (2002) | . | ICZN |
| Aulotandra | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Aulotractus | Phaeosphaerida | Takahashi & Anderson (2000) | . | ICZN |
| Aulura | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Auranticarpa | Apiales | Mabberley (2008) | Pittosporaceae. | ICBN |
| Auranticordis | Marimonadida | Howe et al. (2011) | . | ICZN |
| Aurantimonas | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Aurantiochytrium | Thraustochytriales | Yokoyama & Honda (2007) | . | ICBN |
| Auraspora | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Auraticoccus | Propionibacteriales | Alonso-Vega et al. (2011); Ludwig et al. (2012) | Propionibacteriaceae. | ICNB |
| Aurearena | Aurearenales | Kai et al. (2008) | . | ICBN |
| Aureibacter | Cytophagales | Yoon et al. (2011) | . | ICNB |
| Aureimonas | Rhizobiales | Rathsack et al. (2011) | . | ICNB |
| Aureispira | Sphingobacteriales | Hosoya et al. (2006) | . | ICNB |
| Aureitalea | Flavobacteriales | Park et al. (2012) | . | ICNB |
| Aurelia | Semaeostomeae | Kramp (1961) | . | ICZN |
| Aureliana | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Aureobacterium | Micrococcales | Garrity et al. (2005); Suzuki & Hamada (2012) | Later synonym of Microbacterium. | ICNB |
| Aureococcus | Pelagomonadales | Andersen & Preisig (2000) | . | ICBN |
| Aureolaria | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Aureolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Aureoumbra | Sarcinochrysidales | Andersen & Preisig (2000) | . | ICBN |
| Aurichona | Exogemmida | Lynn (2008) | . | ICZN |
| Aurigamonas | Pansomonadida | Vickerman et al. (2005); Howe et al. (2009) | . | ICZN |
| Aurinia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Auriparus | Passeriformes | Clements (2007) | . | ICZN |
| Auritidibacter | Micrococcales | Yassin et al.(2011); Ludwig et al. (2012) | Micrococcaceae. | ICNB |
| Aurosa | Semaeostomeae | Kramp (1961) | . | ICZN |
| Aurosphaera | | Kristiansen & Preisig (2001) | Domain Eucarya - Kingdom Straminipila - Phylum Ochrophyta. "Aurosphaeraceae". | ICBN |
| Austeruseus | Parachela | Trygvadóttir & Kristensen (2011) | . | ICZN |
| Austinia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Australana | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Australiformis | Moniliformida | Schmidt & Edmonds (1989) | Moniliformidae. | ICZN |
| Australina | Rosales | Mabberley (2008) | Urticaceae. | ICBN |
| Australineus | Heteronemertea | Gibson (1995) | . | ICZN |
| Australocirrus | Sporadotrichida | Lynn (2008) | . | ICZN |
| Australocyathus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Australogyra | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Australolacerta | Squamata | Vitt & Caldwell (2009) | Lacertidae. | ICZN |
| Australomedusa | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Australomussa | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Australophocaena | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001); Mead & Brownell, Jr. (2005) | Cetacea. Later synonym of Phocoena. | ICZN |
| Australopyrum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Australorhynchus | Echinorhynchida | Amin (1985) | . | ICZN |
| Australoricus | Nanaloricida | Heiner et al. (2009) | . | ICZN |
| Australothrix | Urostylida | Lynn (2008) | . | ICZN |
| Austrelaps | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Austrobaileya | Austrobaileyales | Mabberley (2008) | Austrobaileyaceae. | ICBN |
| Austrobrickellia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Austrobuxus | Malpighiales | Mabberley (2008) | Picrodendraceae. | ICBN |
| Austrocactus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Austrocedrus | Cupressales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Austrochaperina | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Austrochloris | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Austroclonium | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Austrocritonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Austrocylindropuntia | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Austrocynoglossum | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Austrodanthonia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Austrodolichos | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Austroeupatorium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Austrofolium | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Austrofossombronia | Fossombroniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Austrognatharia | Bursovaginoidea | Sørensen (2002) | . | ICZN |
| Austrognathia | Bursovaginoidea | Sørensen (2002) | . | ICZN |
| Austrogramme | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Austrohondaella | Hypnales | Iwatsuki et al. (2009) | . | ICBN |
| Austrolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Austrolithon | Corallinales | Schneider & Wynne (2007) | . | ICBN |
| Austrolophozia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Austromatthaea | Laurales | Mabberley (2008) | Monimiaceae. | ICBN |
| Austrometzgeria | Metzgeriales | Crandall-Stotler et al. (2009) | . | ICBN |
| Austromuellera | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Austromyrtus | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Austroneophellia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Austroperipatus | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Austropeucedanum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Austrophilibertiella | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Austrophyllis | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Austroprostoma | Eumonostilifera | Gibson (1995); Chernyshev (2003) | . | ICZN |
| Austropugetia | Gigartinales | Wynne & Schneider (2010) | . | ICBN |
| Austrosteenisia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Austrostipa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Austrosynotis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Austrotaxus | Cupressales | Farjon (2001); Christenhusz et al. (2011) | . | ICBN |
| Austwickia | Micrococcales | Hamada et al. (2010); Ludwig et al. (2012) | Dermatophilaceae. | ICNB |
| Automolus | Passeriformes | Clements (2007) | . | ICZN |
| Autranella | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Autumnalia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Auxemma | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Auxenochlorella | Chlorellales | Ueno et al. (2005) | As AHP lineage. | ICBN |
| Auxopus | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Avagina | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Avahi | Primates | McKenna & Bell (1997) | . | ICZN |
| Avelia | Protoheterotrichida | Lynn (2008) | . | ICZN |
| Avellanita | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Avena | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Avenula | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Averrhoa | Oxalidales | Mabberley (2008) | Oxalidaceae. | ICBN |
| Averrhoidium | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Avestina | Colpodida | Lynn (2008) | . | ICZN |
| Avibacterium | Pasteurellales | Blackall et al. (2005) | . | ICNB |
| Aviceda | Falconiformes | Clements (2007) | . | ICZN |
| Avicennia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Avocettula | Apodiformes | Clements (2007) | . | ICZN |
| Avonia | Caryophyllales | Mabberley (2008) | Portulacaceae. | ICBN |
| Awerintzewia | Arcellinida | Meisterfeld (2000) | Difflugina -- Heleoperidae. | ICZN |
| Axechina | Poecilosclerida | Hooper (2002) | . | ICZN |
| Axinaea | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Axinandra | Myrtales | Mabberley (2008) | Crypteroniaceae. | ICBN |
| Axinella | Halichondrida | Alvarez & Hooper (2002) | . | ICZN |
| Axiniphyllum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Axinyssa | Halichondrida | Erpenbeck & Van Soest (2002) | . | ICZN |
| Axis | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Axonopus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Axos | Hadromerida | Hooper (2002) | . | ICZN |
| Axyris | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Ayapana | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ayapanopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Ayenia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Ayensua | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Aynia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aythya | Anseriformes | Clements (2007) | . | ICZN |
| Azadinium | | Tillmann et al. (2009) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. | ICBN |
| Azadirachta | Sapindales | Mabberley (2008) | Meliaceae. | ICBN |
| Azara | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Azemiops | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Azerella | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora - Class Oligohymenophorea - Subclass Scuticociliatia. | ICZN |
| Azilia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Azima | Brassicales | Mabberley (2008) | Salvadoraceae. | ICBN |
| Azoarcus | Rhodocyclales | Garrity et al. (2005) | . | ICNB |
| Azohydromonas | Burkholderiales | Xie & Yokota (2005) | . | ICNB |
| Azolla | Salviniales | Christenhusz et al. (2011) | . | ICBN |
| Azomonas | Pseudomonadales | Garrity et al. (2005) | . | ICNB |
| Azonexus | Rhodocyclales | Garrity et al. (2005) | . | ICNB |
| Azorella | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Azorhizobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Azoria | Alcyonacea | López-González & Gili (2001); López-González & Gili (2008) | Junior homonym. Replaced by Azoriella. Clavulariidae. | ICZN |
| Azoriella | Alcyonacea | López-González & Gili (2001); López-González & Gili (2008) | Replacement name for Azoria. Clavulariidae. | ICZN |
| Azospira | Rhodocyclales | Garrity et al. (2005) | . | ICNB |
| Azospirillum | Rhodospirillales | Garrity et al. (2005) | . | ICNB |
| Azotobacter | Pseudomonadales | Garrity et al. (2005) | . | ICNB |
| Azovibrio | Rhodocyclales | Garrity et al. (2005) | . | ICNB |
| Aztecaster | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Aztekium | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| B | |
| Babax | Passeriformes | Clements (2007) | . | ICZN |
| Babesia | Piroplasmorida | Perkins et al. (2000) | . | ICZN |
| Babesiosoma | Eucoccidiorida | Perkins et al. (2000) | . | ICZN |
| Babiana | Asparagales | Mabberley (2008) | Iridaceae. | ICBN |
| Babina | Anura | Vitt & Caldwell (2009) | Ranidae. | ICZN |
| Babingtonia | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Babyrousa | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Baccaurea | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Baccharis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Baccharoides | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bachia | Squamata | Vitt & Caldwell (2009) | Gymnophthalmidae. | ICZN |
| Bacillidium | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Bacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Backhousia | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Bacopa | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Bacteriolyticum | Bdellovibrionales | Piñeiro et al. (2008) | Illegitimate. Including type species of Bacteriovorax.. | ICNB |
| Bacteriovorax | Bdellovibrionales | Garrity et al. (2005) | . | ICNB |
| Bacteroides | Bacteroidales | Garrity et al. (2005) | . | ICNB |
| Bactris | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bacularia | Synechococcales | Hoffmann et al. (2005) | . | ICBN |
| Baculea | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Baculella | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Baculellidae. | ICZN |
| Baculogypsina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Calcarinidae. | ICZN |
| Baculogypsinoides | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Calcarinidae. | ICZN |
| Badhamia | Physarales | Yamamoto (1998) | . | ICBN |
| Badhamiopsis | Physarales | Yamamoto (1998) | . | ICBN |
| Badiera | Fabales | Mabberley (2008) | Polygalaceae. | ICBN |
| Badilloa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Badula | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Badusa | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Baeckea | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Baeolophus | Passeriformes | Clements (2007) | . | ICZN |
| Baeometra | Liliales | Mabberley (2008) | Colchicaceae. | ICBN |
| Baeopogon | Passeriformes | Clements (2007) | . | ICZN |
| Baeothele | Euonychophora | Reid (1996) | Peripatopsidae. | ICZN |
| Baeriopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bafodeya | Malpighiales | Mabberley (2008) | Chrysobalanaceae. | ICBN |
| Bafutia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bagassa | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Baggina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bagginidae. | ICZN |
| Bagredinium | Peridiniales | Da et al. (2004) | . | ICBN |
| Baharuia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Bahia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bahianofusus | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Allogromiidae. | ICZN |
| Bahianotubus | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Allogromiidae. | ICZN |
| Bahianthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bahiopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Baijania | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Baikalaster | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Baikalocoleps | Prorodontida | Lynn (2008) | . | ICZN |
| Baikalonis | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Baikalospongia | Haplosclerida | Manconi & Pronzato (2002) | . | ICZN |
| Baikalotheca | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Baikalothigma | Pleuronematida | Lynn (2008) | . | ICZN |
| Baikia | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Baikiaea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Baileya | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Baileyoxylon | Malpighiales | Mabberley (2008) | Achariaceae. | ICBN |
| Baillonella | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Baillonia | Lamiales | Mabberley (2008) | Verbenaceae. | ICBN |
| Baillonius | Piciformes | Clements (2007) | . | ICZN |
| Baimashania | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Baiomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Baissea | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Baitaria | Caryophyllales | Mabberley (2008) | Portulacaceae. | ICBN |
| Bajacalia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bakerella | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Bakeridesia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bakerolimon | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Bakuella | Urostylida | Lynn (2008) | . | ICZN |
| Balaena | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Cetacea. | ICZN |
| Balaenanemertes | Pelagica | Gibson (1995) | . | ICZN |
| Balaeniceps | Ciconiiformes | Clements (2007) | . | ICZN |
| Balaenoptera | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Cetacea. | ICZN |
| Balaka | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Balakata | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Balamuthia | Centramoebida | Patterson et al. (2000); Smirnov et al. (2005); Smirnov et al. (2011) | . | ICZN |
| Balaniger | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | former Calyptrosphaeraceae. | ICBN |
| Balanion | Prorodontida | Lynn (2008) | . | ICZN |
| Balanites | Zygophyllales | Mabberley (2008) | Zygophyllaceae. | ICBN |
| Balanoglossus | Helminthomorpha | Benito (1982) | Ptychoderidae. | ICZN |
| Balanonema | Philasterida | Lynn (2008) | . | ICZN |
| Balanophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Balanophora | Santalales | Mabberley (2008) | Balanophoraceae. | ICBN |
| Balanophyllia | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Balanops | Malpighiales | Mabberley (2008) | Balanopaceae. | ICBN |
| Balantidioides | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora - Class Spirotrichea - Subclass Hypotrichia. | ICZN |
| Balantidion | Haptorida | Lynn (2008) | . | ICZN |
| Balantidium | Vestibuliferida | Lynn (2008) | . | ICZN |
| Balantiophorus | Colpodida | Lynn (2008) | Later synonym of Cyrtolophosis?. | ICZN |
| Balantiopsis | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Balantiopteryx | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Balatro | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Balaustion | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Balbiania | Balbianiales | Schneider & Wynne (2007) | . | ICBN |
| Balbisia | Geraniales | Mabberley (2008) | Ledocarpaceae. | ICBN |
| Baldinia | Suessiales | Hansen et al. (2007); Moestrup et al. (2009); Siano et al. (2010) | . | ICBN |
| Baldockia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Balduina | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Baldwiniella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Balearica | Gruiformes | Clements (2007) | . | ICZN |
| Balebreviceps | Anura | Vitt & Caldwell (2009) | Brevicipitidae. | ICZN |
| Balechina | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Balella | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Balfourodendron | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Balgooya | Fabales | Mabberley (2008) | Polygalaceae. | ICBN |
| Balionemertes | Palaeonemertea | Kajihara et al. (2008) | . | ICZN |
| Balionycteris | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Baliospermum | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Balladinopsis | Stichotrichida | Lynn (2008) | nomen dubium. | ICZN |
| Balladyna | Stichotrichida | Lynn (2008) | Earlier synonym of Cyrtohymena?. | ICZN |
| Ballantinia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Ballia | Balliales | Schneider & Wynne (2007) | . | ICBN |
| Balliella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Balliopsis | Batrachospermales | Schneider & Wynne (2007) | . | ICBN |
| Balliviaspongia | Haplosclerida | Manconi & Pronzato (2002) | . | ICZN |
| Ballochia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Ballodora | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Ballota | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Balmea | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Balnearium | Aquificales | Takai et al. (2003) | . | ICNB |
| Balneatrix | Oceanospirillales | Garrity et al. (2005) | . | ICNB |
| Balneimonas | Rhizobiales | Takeda et al. (2004) | Not Balneomonas. | ICNB |
| Balneola | | Urios et al. (2006); Ludwig et al. (2011) | Domain Bacteria - Phylum Bacteroidetes - Class Cytophagia. | ICNB |
| Baloghia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Baloskion | Poales | Mabberley (2008) | Restionaceae. | ICBN |
| Balsamocarpon | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Balsamocitrus | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Balsamorhiza | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Baltalimania | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Balthasaria | Ericales | Mabberley (2008) | Pentaphylacaceae. | ICBN |
| Balticammina | Trochamminida | Kaminski (2000) | Trochammininae, Trochamminacea. | ICZN |
| Baltimora | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bambekea | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Bambusa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bambusicola | Galliformes | Clements (2007) | . | ICZN |
| Bambusina | Desmidiales | Gontcharov (2008) | . | ICBN |
| Bamiania | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Bampsia | Lamiales | Mabberley (2008) | Linderniaceae. | ICBN |
| Banara | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Bandia | Macropodiniida | Lynn (2008) | . | ICZN |
| Bandicota | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bangia | Bangiales | Schneider & Wynne (2007) | . | ICBN |
| Bangiadulcis | Bangiales | Wynne & Schneider (2010) | Later synonym of Bangia. | ICBN |
| Bangiopsis | Stylonematales | Schneider & Wynne (2007) | . | ICBN |
| Bangsia | Passeriformes | Clements (2007) | . | ICZN |
| Banisteriopsis | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Banksia | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Bannerella | Textulariida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Eggerellidae. | ICZN |
| Banyulsella | Stichotrichida | Lynn (2008) | . | ICZN |
| Baolia | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Baphia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Baphiopsis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Baptisia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Baptorhachis | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Barabattoia | Scleractinia | Yabe & Sugiyama (1941); Cairns et al. (1999); Veron (2000) | Not "Barababanoia" or "Barahabanoia". | ICZN |
| Baratranthus | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Barbacenia | Pandanales | Mabberley (2008) | Velloziaceae. | ICBN |
| Barbaceniopsis | Pandanales | Mabberley (2008) | Velloziaceae. | ICBN |
| Barbarea | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Barbastella | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Barbella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Barbellopsis | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Barberetta | Commelinales | Mabberley (2008) | Haemodoraceae. | ICBN |
| Barbeuia | Caryophyllales | Mabberley (2008) | Barbeuiaceae. | ICBN |
| Barbeya | Rosales | Mabberley (2008) | Barbeyaceae. | ICBN |
| Barbeyella | Echinosteliales | Yamamoto (1998) | . | ICBN |
| Barbieria | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Barbilophozia | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Barbosella | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Barbourinella | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Verneuilinidae. | ICZN |
| Barbourula | Anura | Vitt & Caldwell (2009) | Bombinatoridae. | ICZN |
| Barbrodria | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Barbula | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Barbulanympha | Trichonymphida | Cepicka et al. (2010) | . | ICZN |
| Barcella | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Barcino | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Barclaya | Nymphaeales | Mabberley (2008) | Nymphaeaceae. | ICBN |
| Bardeliella | Colpodida | Lynn (2008) | . | ICZN |
| Bardunovia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Barentsia | Coloniales | Emschermann (1972) | Barentsiidae. | ICZN |
| Bargenys | Anura | Vitt & Caldwell (2009) | Microhylidae. | ICZN |
| Bargmannia | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Bargoniella | | Fensome et al. (1993); Skovgaard et al. (2007) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. Former Blastodiniales. | ICBN |
| Barisia | Squamata | Vitt & Caldwell (2009) | Anguidae. | ICZN |
| Barjonia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Barkeria | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Barkleyanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Barklya | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Barkudia | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Barleria | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Barleriola | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Barlia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Barnadesia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Barnardius | Psittaciformes | Clements (2007) | . | ICZN |
| Barnebya | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Barnebydendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Barneoudia | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Barnesiella | Bacteroidales | Sakamoto et al. (2007) | . | ICNB |
| Barnettia | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Barnhartia | Fabales | Mabberley (2008) | Polygalaceae. | ICBN |
| Barongia | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Baroniella | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Barringtonia | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Barroella | Oxymonadida | Brugerolle & Lee (2000) | . | ICZN |
| Barrosoa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Barrouxia | Eucoccidiorida | Perkins et al. (2000) | . | ICZN |
| Barrufeta | Gymnodiniales | Sampedro et al. (2011) | . | ICBN |
| Barteria | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Barthea | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Barthlottia | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Bartholina | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bartholomaea | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Bartholomea | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bartleia | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Bartlettia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bartlettina | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bartonella | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Bartonia | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Bartoniella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Bartramia | Bartramiales | Goffinet et al. (2009) | . | ICBN |
| Bartramia | Charadriiformes | Clements (2007) | . | ICZN |
| Bartramiopsis | Polytrichales | Goffinet et al. (2009) | . | ICBN |
| Bartsia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Bartsiella | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Barycholos | Anura | Vitt & Caldwell (2009) | Brachycephalidae. | ICZN |
| Baryphthengus | Coraciiformes | Clements (2007) | . | ICZN |
| Basananthe | Malpighiales | Mabberley (2008) | Passifloraceae. | ICBN |
| Basedowia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Basella | Caryophyllales | Mabberley (2008) | Basellaceae. | ICBN |
| Baseodiscus | Heteronemertea | Gibson (1995) | . | ICZN |
| Baseonema | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Basfia | Pasteurellales | Kuhnert et al. (2010) | . | ICNB |
| Basidiophora | Peronosporales | Dick (2001); Kirk et al. (2008) | Peronosporaceae. | ICBN |
| Basileuterus | Passeriformes | Clements (2007) | . | ICZN |
| Basilicum | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Basiliscus | Squamata | Vitt & Caldwell (2009) | Iguanidae. | ICZN |
| Basilornis | Passeriformes | Clements (2007) | . | ICZN |
| Basiphyllaea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Basisperma | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Basistemon | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Baskervilla | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bassaricyon | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Bassariscus | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Bassecoia | Dipsacales | Mabberley (2008) | Caprifoliaceae. | ICBN |
| Basselinia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bassia | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Bassia | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Bassiana | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Bastardia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bastardiastrum | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bastardiopsis | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Batagur | Testudinata | Vitt & Caldwell (2009) | Geomydidae. | ICZN |
| Batara | Passeriformes | Clements (2007) | . | ICZN |
| Batemannia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Batesia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Batesimalva | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bathelia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Bathiorhamnus | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Bathmocercus | Passeriformes | Clements (2007) | . | ICZN |
| Bathochordaeus | Appendicularia | Fenaux (1998) | . | ICZN |
| Bathocyroe | Lobata | Harbison & Madin (1982) | . | ICZN |
| Bathyalcyon | Alcyonacea | Bayer (1981) | Alcyoniidae. | ICZN |
| Bathyascidia | Phlebobranchia | Monniot & Monniot (1972); Kott (1998) | Junior synonym of Ascidia. | ICZN |
| Bathybelos | Aphragmophora | Bieri (1991) | Bathybelosidae. | ICZN |
| Bathycoccus | Mamiellales | Moestrup (2000); Marin & Melkonian (2010) | . | ICBN |
| Bathyctena | Cydippida | Harbison & Madin (1982) | . | ICZN |
| Bathycyathus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Bathydactylus | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bathydorus | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Bathyechiniscus | Arthrotardigrada | Kinchin (1994) | . | ICZN |
| Bathyergus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bathykorus | Narcomedusae | Raskoff (2010) | . | ICZN |
| Bathynemertes | Pelagica | Gibson (1995); Kajihara et al. (2008) | . | ICZN |
| Bathyoncus | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Styelidae. | ICZN |
| Bathypathes | Antipatharia | Opresko (2002) | . | ICZN |
| Bathypera | Stolidobranchia | Monniot & Monniot (1972) | Pyuridae. | ICZN |
| Bathyphellia | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bathyphysa | Siphonophorae | Bouillon et al. (2006) | . | ICZN |
| Bathypsammia | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Bathypyura | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Pyuridae. | ICZN |
| Bathyraja | Rajiformes | Nelson (2006) | . | ICZN |
| Bathysa | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bathysiphon | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bathysiphonidae. | ICZN |
| Bathyspadella | Phragmophora | Bieri (1991) | Spadellidae. | ICZN |
| Bathystyeloides | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Styelidae. | ICZN |
| Bathytelesto | Alcyonacea | Bayer (1981) | Clavulariidae. | ICZN |
| Bathyxiphus | Hexactinosida | Reiswig & Wheeler (2002) | . | ICZN |
| Batillipes | Arthrotardigrada | Kinchin (1994) | . | ICZN |
| Batis | Passeriformes | Clements (2007) | . | ICZN |
| Batis | Brassicales | Mabberley (2008) | Bataceae. | ICBN |
| Batocarpus | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Batomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Batopedina | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Batopilasia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Batrachophrynus | Anura | Vitt & Caldwell (2009) | Ceratophryidae. | ICZN |
| Batrachoseps | Caudata | Vitt & Caldwell (2009) | Plethodontidae. | ICZN |
| Batrachospermum | Batrachospermales | Schneider & Wynne (2007) | . | ICBN |
| Batrachostomus | Caprimulgiformes | Clements (2007) | . | ICZN |
| Batrachuperus | Caudata | Vitt & Caldwell (2009) | Hynobiidae. | ICZN |
| Batrachyla | Anura | Vitt & Caldwell (2009) | Ceratophryidae. | ICZN |
| Batrachylodes | Anura | Vitt & Caldwell (2009) | Ceratobatrachidae. | ICZN |
| Batzella | Poecilosclerida | Van Soest (2002) | . | ICZN |
| Baudouinia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bauera | Oxalidales | Mabberley (2008) | Cunoniaceae. | ICBN |
| Bauerus | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Bauhinia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bauldia | Rhizobiales | Yee et al. (2010) | . | ICNB |
| Baumia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Bavariicoccus | Lactobacillales | Schmidt et al. (2009) | . | ICNB |
| Bavayia | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Baxteria | Dasypogonales | Mabberley (2008) | Dasypogonaceae. | ICBN |
| Bayabusa | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Bayerxenia | Alcyonacea | Alderslade (2001) | Xeniidae. | ICZN |
| Baynesia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Baznosanuia | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora - Class Litostomatea - Subclass Haptoria. | ICZN |
| Bazzania | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Bdallophytum | Malvales | Mabberley (2008) | Cytinaceae. | ICBN |
| Bdelloidina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Coscinophragmatidae. | ICZN |
| Bdellovibrio | Bdellovibrionales | Garrity et al. (2005) | . | ICNB |
| Bdeogale | Carnivora | McKenna & Bell (1997) | . | ICZN |
| Beamys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Beatogordius | Gordioidea | Schmidt-Rhaesa (2002); Poinar Jr. (2008) | . | ICZN |
| Beatragus | Artiodactyla | Grubb (2005) | . | ICZN |
| Beauchampia | Flosculariaceae | Segers (2002); Segers (2007) | . | ICZN |
| Beauchampiella | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Beaufortia | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Beaumontia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Beauprea | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Beaupreopsis | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Bebbia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bebryce | Alcyonacea | Bayer (1981) | Plexauridae. | ICZN |
| Beccarianthus | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Beccaricystis | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Beccarinda | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Beccariophoenix | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Beckerella | Gelidiales | Schneider & Wynne (2007) | Later synonym of Ptilophora. | ICBN |
| Beckingia | Chloramoebales | Ettl (1978) | . | ICBN |
| Beckmannia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Beckwithia | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Beclardia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Becquerelia | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Bedotella | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Beella | Globigerinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Globigerinidae. | ICZN |
| Beersena | Synhymeniida | Lynn (2008) | . | ICZN |
| Beesia | Ranunculales | Mabberley (2008) | Ranunculaceae. | ICBN |
| Beeveria | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Beggiatoa | Thiotrichales | Garrity et al. (2005) | . | ICNB |
| Begonia | Cucurbitales | Mabberley (2008) | Begoniaceae. | ICBN |
| Beguea | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Behaimia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Behillia | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nodosariidae. | ICZN |
| Behnia | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Behuria | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Beijerinckia | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Beilschmiedia | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Beirnaertia | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Beiselia | Sapindales | Mabberley (2008) | Burseraceae. | ICBN |
| Bejaranoa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bejaria | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Belaria | | Bass et al. (2009) | Domain Eucarya - Phylum Cercozoa - Class Granofilosea. | ICZN |
| Belaria | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lagynidae. | ICZN |
| Belemia | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Belencita | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Bellactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bellendena | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Bellevalia | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Bellibarbula | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Bellida | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Belliella | Cytophagales | Brettar et al. (2004); Ludwig et al. (2011) | . | ICNB |
| Bellilinea | Anaerolineales | Yamada et al. (2007) | . | ICNB |
| Bellis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bellium | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Belloa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bellonella | Alcyonacea | Bayer (1981) | Alcyoniidae. | ICZN |
| Bellonia | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Bellucia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Belnapia | Rhodospirillales | Reddy et al. (2006) | . | ICNB |
| Beloglottis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Belomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Belonophora | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Belonophrya | Haptorida | Lynn (2008) | . | ICZN |
| Belosynapsis | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Bembicia | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Bencomia | Rosales | Mabberley (2008) | Rosaceae. | ICBN |
| Benevidesia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Benguellia | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Benincasa | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Benitoa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Benitotania | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Benjaminia | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Benkara | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bennettiella | Heteronemertea | Gibson (1995) | . | ICZN |
| Bennettiodendron | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Benoicanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Benoistia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Benthamia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Benthamiella | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Benthamina | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Benthascidia | Phlebobranchia | Monniot & Monniot (1972) | Octacnemidae. | ICZN |
| Benthobatis | Torpediniformes | Nelson (2006) | . | ICZN |
| Benthocodon | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Benthontophrys | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora. | ICZN |
| Bentinckia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bentleya | Apiales | Mabberley (2008) | Pittosporaceae. | ICBN |
| Benua | Peronosporales | Dick (2001); Kirk et al. (2008) | Peronosporaceae. | ICBN |
| Benzaitenia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Benzingia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Benzonia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bequaertia | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Berardius | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Cetacea. | ICZN |
| Berberidopsis | Berberidopsidales | Mabberley (2008) | Berberidopsidaceae. | ICBN |
| Berberis | Ranunculales | Mabberley (2008) | Berberidaceae. | ICBN |
| Berchemia | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Berchemiella | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Bereczkya | | Kiss et al. (2009) | Domain Eucarya - Phylum Cercozoa. | ICZN |
| Berenice | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Bergenia | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Bergera | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Bergeranthus | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Bergeriella | Neisseriales | Xie & Yokota (2005) | . | ICNB |
| Bergerocactus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Bergeronia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bergeyella | Flavobacteriales | Garrity et al. (2005) | . | ICNB |
| Berggrenia | Globigerinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Globorotaliidae. | ICZN |
| Berghesia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Berghiella | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Bergia | Malpighiales | Mabberley (2008) | Elatinaceae. | ICBN |
| Bergophrya | Haptorida | Lynn (2008) | . | ICZN |
| Berhautia | Santalales | Mabberley (2008) | Loranthaceae. | ICBN |
| Beringia | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Beringiella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Berkheya | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Berlandiera | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Berlepschia | Passeriformes | Clements (2007) | . | ICZN |
| Berlinia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Berlinianche | Cucurbitales | Mabberley (2008) | Apodanthaceae. | ICBN |
| Bermanella | Oceanospirillales | Pinhassi et al. (2009) | . | ICNB |
| Bermudezella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Victoriellidae. | ICZN |
| Bermudezinella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nonionidae. | ICZN |
| Bernardia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Bernardinium | Gymnodiniales | Fensome et al. (1993) | . | ICBN |
| Berneuxia | Ericales | Mabberley (2008) | Diapensiaceae. | ICBN |
| Bernoullia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Beroe | Beroida | Harbison & Madin (1982) | . | ICZN |
| Berrillia | Stolidobranchia | Monniot & Monniot (1972) | Styelidae. | ICZN |
| Berroa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Berrya | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bersama | Geraniales | Mabberley (2008) | Melianthaceae. | ICBN |
| Berteroa | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Berteroella | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Bertholletia | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Bertiera | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bertolanius | Parachela | Özdikmen (2008) | Replacement name for Amphibolus. | ICZN |
| Bertolinella | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Bertolonia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Bertya | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Berula | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Berwaldia | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Berylmys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Berylsimpsonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Berzelia | Bruniales | Mabberley (2008) | Bruniaceae. | ICBN |
| Besa | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Bescherellia | Hypnodendrales | Goffinet et al. (2009) | . | ICBN |
| Beschorneria | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Besleria | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Besnoitia | Eucoccidiorida | Perkins et al. (2000) | . | ICZN |
| Bessera | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Bestia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Beta | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Betaphycus | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Bettongia | Australidelphia | McKenna & Bell (1997) | . | ICZN |
| Betula | Fagales | Mabberley (2008) | Betulaceae. | ICBN |
| Beutenbergia | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Bewsia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Beyeria | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Bezedniella | Peritrichida | Lynn (2008); Zhan et al. (2009) | . | ICZN |
| Bhargavaea | Bacillales | Manorama et al. (2009) | . | ICNB |
| Bhatiella | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Bhesa | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Bhidea | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bhutanthera | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Biantheridion | Jungermanniales | Söderström et al. (2010) | . | ICBN |
| Biarritzina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Victoriellidae. | ICZN |
| Biarum | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Bias | Passeriformes | Clements (2007) | . | ICZN |
| Biasterigerina | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Asterigerinatidae. | ICZN |
| Biatas | Passeriformes | Clements (2007) | . | ICZN |
| Bibersteinia | Pasteurellales | Blackall et al. (2007) | . | ICNB |
| Bibimys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bibrachium | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Bicidium | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bicorona | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Bicoronella | Urostylida | Lynn (2008) | . | ICZN |
| Bicosoeca | Bicoecales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Bicosta | Acanthoecida | Leadbeater & Thomsen (2000) | . | ICZN |
| Bicuiba | Magnoliales | Mabberley (2008) | Myristicaceae. | ICBN |
| Bidens | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Biebersteinia | Sapindales | Mabberley (2008) | Biebersteiniaceae. | ICBN |
| Biecheleria | Suessiales | Moestrup et al. (2009) | . | ICBN |
| Biecheleriopsis | Suessiales | Moestrup et al. (2009) | Phylogenetically included within the Biecheleriaceae. | ICBN |
| Biemna | Poecilosclerida | Hajdu & Van Soest (2002) | . | ICZN |
| Bienertia | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Biermannia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bifarilaminella | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ellipsolagenidae. | ICZN |
| Bifarinella | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Pavoninidae. | ICZN |
| Bifidobacterium | Bifidobacteriales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Bifilida | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Bifora | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bifrenaria | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bigelowia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bigelowiella | Chlorarachniales | Ishida et al. (2007); Ota et al. (2007) | . | ICBN |
| Bigenerina | Textulariida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Textulariidae. | ICZN |
| Bigenerinoides | Textulariida | Kaminski (2008) | Textulariinae. | ICZN |
| Biggaria | Philasterida | Lynn (2008) | . | ICZN |
| Biggariella | Philasterida | Lynn (2008) | Nomen nudum. | ICZN |
| Bignonia | Lamiales | Mabberley (2008) | Bignoniaceae. | ICBN |
| Biholosticha | Urostylida | Lynn (2008) | . | ICZN |
| Bihospites | Postgaardida | Breglia et al. (2010) | Clade "Symbiontida". | ICZN |
| Bijlia | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Bikinia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bikkia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bilacunaria | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bilamellophrya | Haptorida | Lynn (2008) | . | ICZN |
| Billardia | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Billardiera | Apiales | Mabberley (2008) | Pittosporaceae. | ICBN |
| Billbergia | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Billia | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Billieturnera | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Biloculinella | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hauerinidae. | ICZN |
| Bilophila | Desulfovibrionales | Garrity et al. (2005) | . | ICNB |
| Bimeria | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Binghamia | Rhodymeniales | Schneider & Wynne (2007) | . | ICBN |
| Binghamiopsis | Rhodymeniales | Schneider & Wynne (2007) | . | ICBN |
| Binotia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Binucleata | Microsporida | Refardt et al. (2008) | . | ICZN |
| Binucleospora | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Biomyxa | Aconchulinida | Bass et al. (2009) | . | ICZN |
| Biondia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Biophytum | Oxalidales | Mabberley (2008) | Oxalidaceae. | ICBN |
| Biostraticola | Enterobacteriales | Verbarg et al. (2008) | . | ICNB |
| Bipalmatum | | Lynn (2008) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Ciliophora. | ICZN |
| Bipes | Squamata | Vitt & Caldwell (2009) | Bipedidae. | ICZN |
| Bipinnula | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bipseudostomatella | Arcellinida | Snegovaya & Alekperov (2005) | Bipseudostomatidae (classification not confirmed). | ICZN |
| Bipteria | Bivalvulida | Lom & Dyková (2006) | . | ICZN |
| Birgea | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Birojimia | Urostylida | Lynn (2008) | . | ICZN |
| Birsteiniolla | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Rzehakinidae. | ICZN |
| Bisaccioides | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bisacciidae. | ICZN |
| Bisaccium | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bisacciidae. | ICZN |
| Bisboeckelera | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Bischofia | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Biscutella | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Biserrula | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bisgaardia | Pasteurellales | Foster et al. (2011) | . | ICNB |
| Bisglaziovia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Bisgoeppertia | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Bishopalea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bishopanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bishopiella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bishovia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bismarckia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bison | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Bispironympha | Trichonymphida | Cepicka et al. (2010) | . | ICZN |
| Bissetia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bistichella | Stichotrichida | He & Xu (2011) | . | ICZN |
| Biswamoyopterus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Biswarea | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Bithekammina | Astrorhizida | Da Silva et al. (2011) | . | ICZN |
| Bitia | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bitis | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Bitricha | Macropodiniida | Lynn (2008) | . | ICZN |
| Bitrichia | Hibberdiales | Kristiansen & Preisig (2001) | Stylococcaceae. | ICBN |
| Bituminaria | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bivinia | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Bivonaea | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Bixa | Malvales | Mabberley (2008) | Bixaceae. | ICBN |
| Bizionia | Flavobacteriales | Nedashkovskaya et al. (2005) | . | ICNB |
| Biziura | Anseriformes | Clements (2007) | . | ICZN |
| Bizonula | Philasterida | Lynn (2008) | . | ICZN |
| Bizonula | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Blachia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Blackallia | Rosales | Mabberley (2008) | Rhamnaceae. | ICBN |
| Blackfordia | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Blackstonia | Gentianales | Mabberley (2008) | Gentianaceae. | ICBN |
| Blaesodactylus | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Blainvillea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blakea | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Blakeanthus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blakiella | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blanchetia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blanchetiodendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Blancoa | Commelinales | Mabberley (2008) | Haemodoraceae. | ICBN |
| Blandfordia | Asparagales | Mabberley (2008) | Blandfordiaceae. | ICBN |
| Blanfordimys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Blanus | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Blarina | Eulipotyphla | McKenna & Bell (1997); Murphy et al. (2001) | . | ICZN |
| Blarinella | Eulipotyphla | McKenna & Bell (1997); Murphy et al. (2001) | . | ICZN |
| Blarinomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Blasia | Blasiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Blastemanthus | Malpighiales | Mabberley (2008) | Ochnaceae. | ICBN |
| Blastobacter | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Blastocaulon | Poales | Mabberley (2008) | Eriocaulaceae. | ICBN |
| Blastocerus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Blastochloris | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Blastococcus | Frankiales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Blastocrithidia | Trypanosomatida | Moreira et al. (2004) | . | ICZN |
| Blastocystis | Blastocystales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Blastodinium | | Fensome et al. (1993); Skovgaard et al. (2007) | Domain Eucarya - Kingdom Alveolatobiontes - Phylum Dinozoa - Class Dinophyceae. Former Blastodiniales. | ICBN |
| Blastomonas | Sphingomonadales | Garrity et al. (2005) | . | ICNB |
| Blastomussa | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Blastophye | Cryptonemiales | Silva (2002); Schneider & Wynne (2007) | . | ICBN |
| Blastopirellula | Planctomycetales | Schlesner et al. (2004) | . | ICNB |
| Blastotrochus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Blastulidium | Leptomitales | Dick (2001); Kirk et al. (2008) | Leptomitales. | ICBN |
| Blastus | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Blattabacterium | Flavobacteriales | Garrity et al. (2005) | . | ICNB |
| Blautia | Clostridiales | Liu et al. (2008) | . | ICNB |
| Bleasdalea | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Blechnum | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Blechum | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Bleda | Passeriformes | Clements (2007) | . | ICZN |
| Bleekrodea | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Blennodia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Blennosperma | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blennospora | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blennothrix | Oscillatoriales | Hoffmann et al. (2005) | . | ICBN |
| Blepharandra | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Blepharidachne | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Blepharidium | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Blepharidophyllum | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Blepharipappus | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blepharis | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Blepharisma | Heterotrichida | Lynn (2008) | . | ICZN |
| Blepharispermum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blepharistemma | Malpighiales | Mabberley (2008) | Rhizophoraceae. | ICBN |
| Blepharizonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blepharocalyx | Myrtales | Mabberley (2008) | Myrtaceae. | ICBN |
| Blepharocarya | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Blepharocodon | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharoconus | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharocorys | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharocysta | Peridiniales | Fensome et al. (1993) | . | ICBN |
| Blepharodon | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Blepharolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Blepharomonas | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharoplanum | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharoposthium | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharosphaera | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blepharostoma | Ophryoglenida | Lynn (2008) | Nomen nudum. | ICZN |
| Blepharostoma | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Blepharozoum | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Blephilia | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Bletia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bletilla | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Blighia | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Blighiopsis | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Blindia | Grimmiales | Goffinet et al. (2009) | . | ICBN |
| Blinksia | Gigartinales | Schneider & Wynne (2007) | . | ICBN |
| Blinkworthia | Solanales | Mabberley (2008) | Convolvulaceae. | ICBN |
| Blomia | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Blommersia | Anura | Vitt & Caldwell (2009) | Mantellidae. | ICZN |
| Bloomeria | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Blossfeldia | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Blotiella | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Blumea | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blumenbachia | Cornales | Mabberley (2008) | Loasaceae. | ICBN |
| Blumeodendron | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Blumeopsis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Blutaparon | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Blysmasphaera | Allogromiida | Kaminski (2000) | Lagynidae. | ICZN |
| Blysmopsis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Blysmus | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Blythia | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Blythipicus | Piciformes | Clements (2007) | . | ICZN |
| Blyttia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Blyxa | Alismatales | Mabberley (2008) | Hydrocharitaceae. | ICBN |
| Boa | Squamata | Vitt & Caldwell (2009) | Serpentes. Boidae. | ICZN |
| Boaedon | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bobartia | Asparagales | Mabberley (2008) | Iridaceae. | ICBN |
| Bobea | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bobgunnia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bocagea | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Bocageopsis | Magnoliales | Mabberley (2008) | Annonaceae. | ICBN |
| Bocconia | Ranunculales | Mabberley (2008) | Papaveraceae. | ICBN |
| Bocoa | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bocquillonia | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Boderia | Allogromiida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Lagynidae. | ICZN |
| Bodo | Eubodonida | Moreira et al. (2004) | . | ICZN |
| Bodomorpha | Glissomonadida | Howe et al. (2009) | . | ICZN |
| Boea | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Boeberoies | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Boechera | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Boehmantis | Anura | Vitt & Caldwell (2009) | Mantellidae. | ICZN |
| Boehmeria | Rosales | Mabberley (2008) | Urticaceae. | ICBN |
| Boeica | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Boekelovia | | Kristiansen & Preisig (2001) | Domain Eucarya - Kingdom Straminipila - Phylum Ochrophyta. | ICBN |
| Boelckea | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Boenninghausenia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Boergeseniella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Boerhavia | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Boerlagea | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Boeromedusa | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Boesenbergia | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Bogertia | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Bogertophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bognera | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Bogoria | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bogoriella | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Boholia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bohuslavia | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Boiga | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Boiruna | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Boissonneaua | Apodiformes | Clements (2007) | . | ICZN |
| Bokermannohyla | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Bolandra | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Bolanosa | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bolanthus | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Bolax | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bolbitis | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Bolbopsittacus | Psittaciformes | Clements (2007) | . | ICZN |
| Bolborhynchoides | Echinorhynchida | Amin (1985) | . | ICZN |
| Bolborhynchus | Psittaciformes | Clements (2007) | . | ICZN |
| Bolboschoenus | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Bolbosoma | Polymorphida | Amin (1985) | . | ICZN |
| Bolbostemma | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Boldia | Compsopogonales | Schneider & Wynne (2007) | . | ICBN |
| Boldoa | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Bolidomonas | Bolidomonadales | Guillou et al. (1999) | . | ICBN |
| Bolinopsis | Lobata | Harbison & Madin (1982) | . | ICZN |
| Bolitoglossa | Caudata | Vitt & Caldwell (2009) | Plethodontidae. | ICZN |
| Bolivia | Eugregarinorida | Corbel (1968); Perkins et al. (2000) | Misspelling of Boliviana. | ICZN |
| Boliviana | Eugregarinorida | Corbel (1968); Perkins et al. (2000) | . | ICZN |
| Bolivina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinidae. | ICZN |
| Bolivinella | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinellidae. | ICZN |
| Bolivinellina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinidae. | ICZN |
| Bolivinita | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinitidae. | ICZN |
| Bollea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bolliella | Globigerinida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Globigerinidae. | ICZN |
| Bolocera | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Boloceractis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Boloceroides | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Boloceropsis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bolomys | Rodentia | McKenna & Bell (1997); Musser & Carleton (2005) | Later synonym of Necromys. | ICZN |
| Bolophyta | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bolosoma | Lyssacinosida | Tabachnick (2002) | . | ICZN |
| Boltenia | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Pyuridae. | ICZN |
| Bolteniopsis | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Pyuridae. | ICZN |
| Boltonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bolusafra | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bolusanthus | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bolusia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bolusiella | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bolyeria | Squamata | Vitt & Caldwell (2009) | Serpentes. Bolyeriidae. | ICZN |
| Bomarea | Liliales | Mabberley (2008) | Alstroemeriaceae. | ICBN |
| Bombax | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Bombina | Anura | Vitt & Caldwell (2009) | Bombinatoridae. | ICZN |
| Bombulina | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Glandulinidae. | ICZN |
| Bombycilla | Passeriformes | Clements (2007) | . | ICZN |
| Bommeria | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Bonamia | Haplosporida | Bass et al. (2009) | . | ICZN |
| Bonamia | Solanales | Mabberley (2008) | Convolvulaceae. | ICBN |
| Bonania | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Bonannia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bonasa | Galliformes | Clements (2007) | . | ICZN |
| Bonatea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Boneia | Chiroptera | McKenna & Bell (1997); Simmons (2005) | Later synonym of Rousettus. | ICZN |
| Bonellia | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Bonetiella | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Bongardia | Ranunculales | Mabberley (2008) | Berberidaceae. | ICBN |
| Bonia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Boninastrea | Scleractinia | Cairns et al. (1999); Veron (2000) | . | ICZN |
| Boninia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Boniodendron | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Bonnemaisonia | Bonnemaisoniales | Schneider & Wynne (2007) | . | ICBN |
| Bonnetia | Malpighiales | Mabberley (2008) | Bonnetiaceae. | ICBN |
| Bonneviella | Leptothecata | Bouillon et al. (2006) | . | ICZN |
| Bonniera | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bonplandia | Ericales | Mabberley (2008) | Polemoniaceae. | ICBN |
| Bontia | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Bonyunia | Gentianales | Mabberley (2008) | Loganiaceae. | ICBN |
| Boocercus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001); Grubb (2005) | Artiodactyla. Later synonym of Tragelaphus. | ICZN |
| Boophis | Anura | Vitt & Caldwell (2009) | Mantellidae. | ICZN |
| Boophone | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Boopis | Asterales | Mabberley (2008) | Calyceraceae. | ICBN |
| Boquila | Ranunculales | Mabberley (2008) | Lardizabalaceae. | ICBN |
| Borago | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Borassodendron | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Borassus | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bordetella | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Bordnamonas | | Adl et al. (2005) | Domain Eucarya - Phylum Euglenozoa - Class Kinetoplastea. | ICZN |
| Boreadinium | Peridiniales | Fensome et al. (1993) | . | ICBN |
| Boreava | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Borelis | Miliolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Alveolinidae. | ICZN |
| Boreohydra | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Boreolithon | Corallinales | Schneider & Wynne (2007) | . | ICBN |
| Boreophyllum | Bangiales | Sutherland et al. (2011) | . | ICBN |
| Boreothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Borgertella | Phaeogromida | Takahashi & Anderson (2000) | . | ICZN |
| Borghiella | Suessiales | Moestrup et al. (2008); Moestrup et al. (2009); Siano et al. (2010) | . | ICBN |
| Borismene | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Borneacanthus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Borneodendron | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Borneophrys | Anura | Vitt & Caldwell (2009) | Megophryidae. | ICZN |
| Borneosicyos | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Bornetia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Bornmuellera | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Bornmuellerantha | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Borodinia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Borojoa | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Boroka | Borokales | Cavalier-Smith & Chao (2006) | . | ICZN |
| Boronella | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Boronia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Borrelia | Spirochaetales | Garrity et al. (2005) | . | ICNB |
| Borrichia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Borsczowia | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Borthwickia | Brassicales | Mabberley (2008) | Excluded from Capparaceae?. | ICBN |
| Borya | Asparagales | Mabberley (2008) | Boryaceae. | ICBN |
| Borzia | Oscillatoriales | Hoffmann et al. (2005) | . | ICBN |
| Borzinema | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Bos | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Boschia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Boschniakia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Boscia | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Bosea | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Bosea | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Boselaphus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Bosistoa | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Bosqueiopsis | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Bossiaea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bossiella | Corallinales | Wynne & Schneider (2010) | . | ICBN |
| Bostrichobranchus | Stolidobranchia | Monniot & Monniot (1972) | Molgulidae. | ICZN |
| Bostrychanthera | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Bostrychia | Ciconiiformes | Clements (2007) | . | ICZN |
| Bostrychia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Bostrychiocolax | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Boswellia | Sapindales | Mabberley (2008) | Burseraceae. | ICBN |
| Botaurus | Ciconiiformes | Clements (2007) | . | ICZN |
| Botellina | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Hippocrepinidae. | ICZN |
| Bothriechis | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Bothriochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bothriocline | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bothriopsides | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Bothriopsis | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Bothriospermum | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Bothriospora | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bothrochilus | Squamata | Vitt & Caldwell (2009) | Serpentes. Pythonidae. | ICZN |
| Bothrochloris | Chloramoebales | Ettl (1978) | . | ICBN |
| Bothrocophias | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Bothrolycus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bothrophthalmus | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bothrops | Squamata | Vitt & Caldwell (2009) | Serpentes. Viperidae. | ICZN |
| Bothrostoma | Armophorida | Lynn (2008) | . | ICZN |
| Botruanthus | Ceriantharia | Tiffon (1987) | . | ICZN |
| Botrucnidiata | Ceriantharia | Tiffon (1987) | . | ICZN |
| Botrucnidifer | Ceriantharia | Tiffon (1987) | . | ICZN |
| Botryarrhena | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Botrychium | Ophioglossales | Christenhusz et al. (2011) | . | ICBN |
| Botrydemnum | Aplousobranchia | Monniot & Monniot (1972) | Didemnidae. | ICZN |
| Botrydiopsis | Mischococcales | Ettl (1978) | . | ICBN |
| Botrydium | Botrydiales | Ettl (1978) | . | ICBN |
| Botryllocarpa | Stolidobranchia | Monniot & Monniot (1972) | Styelidae. | ICZN |
| Botrylloides | Stolidobranchia | Monniot & Monniot (1972) | Styelidae. | ICZN |
| Botryllus | Stolidobranchia | Monniot & Monniot (1972); Monniot (2001) | Styelidae. | ICZN |
| Botrynema | Trachymedusae | Bouillon et al. (2006) | . | ICZN |
| Botryocarpa | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Botryochloris | Mischococcales | Ettl (1978) | . | ICBN |
| Botryochytrium | Thraustochytriales | Yokoyama et al. (2007) | . | ICBN |
| Botryocladia | Rhodymeniales | Schneider & Wynne (2007) | . | ICBN |
| Botryococcus | | Letsch et al. (2009) | Domain Eucarya - Phylum Chlorophyta - Class Trebouxiophyceae. Closely related to Chorycystis. | ICBN |
| Botryocyrtis | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Botryoglossum | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Botryon | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Botryophora | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Botryopyle | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Botryostrobus | Nassellaria | Anderson et al. (2000) | . | ICZN |
| Bottegoa | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Botticula | Heterotrichida | Lynn (2008) | . | ICZN |
| Botuliforma | | Howe et al. (2011) | Domain Eucarya - Phylum Cercozoa - Class Thecofilosea. | ICZN |
| Botuloides | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Nodosariidae. | ICZN |
| Bouchardatia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Bouchea | Lamiales | Mabberley (2008) | Verbenaceae. | ICBN |
| Bouchetia | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Bouea | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Bougainvillea | Caryophyllales | Mabberley (2008) | Nyctaginaceae. | ICBN |
| Bougainvillia | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Bouillonia | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Boulaya | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Boulengerina | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Boulengerula | Gymnophiona | Vitt & Caldwell (2009) | "Caeciliidae". | ICZN |
| Bournea | Lamiales | Mabberley (2008); Möller et al. (2011) | Gesneriaceae. Later synonym of Oreocharis. | ICBN |
| Bourneotrochus | Scleractinia | Cairns et al. (1999) | . | ICZN |
| Bourrellia | Hibberdiales | Kristiansen & Preisig (2001); Cavalier-Smith & Chao (2006) | Chrysocapsaceae (no flagellate stage). | ICBN |
| Bourrellyodesmus | Desmidiales | Gontcharov (2008) | . | ICBN |
| Bourreria | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Bousigonia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Bouteloua | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Boutonia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Bouvardia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bouzetia | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Boveella | Dactylopodida | Rogerson & Patterson (2000); Smirnov et al. (2005) | Vexilliferidae. | ICZN |
| Boveemonas | | Bass et al. (2009) | Domain Eucarya - Phylum Cercozoa - Class Granofilosea. | ICZN |
| Boveria | Thigmotrichida | Lynn (2008) | . | ICZN |
| Bowdichia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bowenia | Cycadales | Mabberley (2008); Christenhusz et al. (2011) | . | ICBN |
| Bowiea | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Bowkeria | Lamiales | Mabberley (2008) | Stilbaceae. | ICBN |
| Bowlesia | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bowmanella | Alteromonadales | Jean et al. (2006) | . | ICNB |
| Boyania | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Boykinia | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Bozasella | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Braarudosphaera | Coccolithales | Jordan et al. (2004); Edvardsen & Medlin (2007) | Braarudosphaeraceae. | ICBN |
| Brabejum | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Bracchiogonium | Mischococcales | Ettl (1978); Silva (1979) | Nomen nudum. Possibly later synonym of Tetraplektron. | ICBN |
| Brachaelurus | Orectolobiformes | Nelson (2006) | . | ICZN |
| Brachanthemum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachelyma | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Brachiaser | Astrophorida | Maldonado (2002) | . | ICZN |
| Brachiola | Microsporida | Canning & Vavra (2000); Franzen et al. (2006) | Junior synonym of Anncaliia. | ICZN |
| Brachiolejeunea | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Brachiones | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Brachionidium | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brachionostylum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachionus | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Brachistus | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Brachonella | Armophorida | Lynn (2008) | . | ICZN |
| Brachtia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brachyachne | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brachybacterium | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Brachybotrys | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Brachycaulos | Saxifragales | Mabberley (2008) | Saxifragaceae. | ICBN |
| Brachycephalus | Anura | Vitt & Caldwell (2009) | Brachycephalidae. | ICZN |
| Brachycereus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Brachychiton | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Brachychloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brachyclados | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachycome | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachycope | Passeriformes | Clements (2007) | . | ICZN |
| Brachycorythis | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brachycylix | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brachydinium | Ptychodiscales | Fensome et al. (1993) | . | ICBN |
| Brachydontium | Grimmiales | Goffinet et al. (2009) | . | ICBN |
| Brachyelytrum | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brachygalba | Galbuliformes | Clements (2007) | . | ICZN |
| Brachyglottis | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachylaena | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachylagus | Lagomorpha | McKenna & Bell (1997) | . | ICZN |
| Brachylepis | Caryophyllales | Mabberley (2008) | Amaranthaceae. | ICBN |
| Brachyloma | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Brachylophon | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Brachylophus | Squamata | Vitt & Caldwell (2009) | Iguanidae. | ICZN |
| Brachymeles | Squamata | Vitt & Caldwell (2009) | Scincidae. | ICZN |
| Brachymeniopsis | Funariales | Goffinet et al. (2009) | . | ICBN |
| Brachymenium | Bryales | Goffinet et al. (2009) | . | ICBN |
| Brachymonas | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Brachynema | Tribonematales | Ettl (1978); Silva (1979) | Later homonym. Replaced by "Brachynematella". | ICBN |
| Brachynema | Santalales | Mabberley (2008) | Olacaceae. | ICBN |
| Brachynematella | Tribonematales | Ettl (1978); Silva (1979) | Replacement name for "Brachynema". | ICBN |
| Brachyophidium | Squamata | Vitt & Caldwell (2009) | Serpentes. Uropeltidae. | ICZN |
| Brachyophis | Squamata | Vitt & Caldwell (2009) | Serpentes. Atractaspididae. | ICZN |
| Brachyorrhos | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Brachyosoma | Endogenida | Lynn (2008) | . | ICZN |
| Brachyotum | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Brachypea | Acoela | Hooge & Tyler (2005) | . | ICZN |
| Brachypeza | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brachyphylla | Chiroptera | McKenna & Bell (1997) | . | ICZN |
| Brachypodium | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brachypteracias | Coraciiformes | Clements (2007) | . | ICZN |
| Brachypterys | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Brachypteryx | Passeriformes | Clements (2007) | . | ICZN |
| Brachyramphus | Charadriiformes | Clements (2007) | . | ICZN |
| Brachyscias | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Brachysiphon | Astrorhizida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Saccamminidae. | ICZN |
| Brachysiphon | Myrtales | Mabberley (2008) | Crypteroniaceae. | ICBN |
| Brachysola | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Brachyspira | Spirochaetales | Garrity et al. (2005) | . | ICNB |
| Brachystegia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brachystele | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brachystelma | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Brachystephanus | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Brachystigma | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Brachysura | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Brachytarsomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Brachytarsophrys | Anura | Vitt & Caldwell (2009) | Megophryidae. | ICZN |
| Brachyteles | Primates | McKenna & Bell (1997) | . | ICZN |
| Brachytheca | Desmidiales | Gontcharov (2008) | . | ICBN |
| Brachytheciastrum | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Brachythecium | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Brachythrix | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brachytome | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Brachytrichia | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Brachytrichiopsis | Nostocales | Hoffmann et al. (2005) | . | ICBN |
| Brachyuromys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bracisepalum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brackenridgea | Malpighiales | Mabberley (2008) | Ochnaceae. | ICBN |
| Brackiella | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Bradburia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bradea | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bradornis | Passeriformes | Clements (2007) | . | ICZN |
| Bradypodion | Squamata | Vitt & Caldwell (2009) | Chamaeleonidae. | ICZN |
| Bradypterus | Passeriformes | Clements (2007) | . | ICZN |
| Bradypus | Xenarthra | McKenna & Bell (1997) | . | ICZN |
| Bradyrhizobium | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Bradyscela | Bdelloida | Segers (2002); Segers (2007) | . | ICZN |
| Bradytriton | Caudata | Vitt & Caldwell (2009) | Plethodontidae. | ICZN |
| Bragginsella | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Brahea | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Brainea | Polypodiales | Christenhusz et al. (2011) | . | ICBN |
| Braithwaitea | Hypnodendrales | Goffinet et al. (2009) | . | ICBN |
| Branchiibius | Micrococcales | Sugimoto et al. (2011); Ludwig et al. (2012) | Dermacoccaceae. | ICNB |
| Branchiocerianthus | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Branchioecetes | Haptorida | Lynn (2008) | . | ICZN |
| Branchioglossum | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Branchiomyces | Saprolegniales | Kirk et al. (2008) | Saprolegniales. | ICBN |
| Branchiostoma | Amphioxiformes | Nelson (2006) | . | ICZN |
| Brandegea | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Brandella | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Brandisia | Lamiales | Mabberley (2008) | Paulowniaceae. | ICBN |
| Brandtiella | Tintinnida | Lynn (2008) | . | ICZN |
| Brandzeia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Branta | Anseriformes | Clements (2007) | . | ICZN |
| Brasacanthus | Echinorhynchida | Thatcher (2001) | Echinorhynchidae. | ICZN |
| Brasenia | Nymphaeales | Mabberley (2008) | Cabombaceae. | ICBN |
| Brasilia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brasilicereus | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Brasiliocroton | Malpighiales | Mabberley (2008) | Euphorbiaceae. | ICBN |
| Brasiliopuntia | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Brasilonema | Nostocales | Fiore et al. (2007) | . | ICBN |
| Brasilotyphlus | Gymnophiona | Vitt & Caldwell (2009) | "Caeciliidae". | ICZN |
| Brassavola | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brassia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brassiantha | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Brassica | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Brassicibacter | Clostridiales | Fang et al. (2012) | . | ICNB |
| Brassiodendron | Laurales | Mabberley (2008) | Lauraceae. | ICBN |
| Brassiophoenix | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Braunblanquetia | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Braunfelsia | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Braunia | Hedwigiales | Goffinet et al. (2009) | . | ICBN |
| Braunsia | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Bravaisia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Braya | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Brayopsis | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Brazoria | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Brazzeia | Ericales | Mabberley (2008) | Lecythidaceae. | ICBN |
| Bredemeyera | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Bredia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Brefeldia | Stemonitales | Yamamoto (1998) | . | ICBN |
| Brehmiella | Chromulinales | Kristiansen & Preisig (2001) | Chrysamoebaceae (biflagellate). | ICBN |
| Breidleria | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Breitfussia | Leucosolenida | Borojevic et al. (2002) | . | ICZN |
| Breizacanthus | Echinorhynchida | Amin (1985) | . | ICZN |
| Bremia | Peronosporales | Dick (2001); Kirk et al. (2008) | Peronosporaceae. | ICBN |
| Bremontiera | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brenandendron | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brenania | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Brenierea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brenneria | Enterobacteriales | Garrity et al. (2005) | . | ICNB |
| Brentisentis | Echinorhynchida | Amin (1985) | . | ICZN |
| Breoghania | Rhizobiales | Gallego et al. (2010) | . | ICNB |
| Breonadia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Breonia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bresslaua | Colpodida | Lynn (2008) | . | ICZN |
| Bresslauides | Colpodida | Lynn (2008) | . | ICZN |
| Bretschneidera | Brassicales | Mabberley (2008) | Akaniaceae. | ICBN |
| Breutelia | Bartramiales | Goffinet et al. (2009) | . | ICBN |
| Brevianthus | Jungermanniales | Crandall-Stotler et al. (2009) | . | ICBN |
| Breviata | Breviatida | Walker et al. (2006); Minge et al. (2009) | . | ICZN |
| Brevibacillus | Bacillales | Garrity et al. (2005) | . | ICNB |
| Brevibacterium | Micrococcales | Garrity et al. (2005); Ludwig et al. (2012) | . | ICNB |
| Breviceps | Anura | Vitt & Caldwell (2009) | Brevicipitidae. | ICZN |
| Brevicollus | Aplousobranchia | Kott (1998) | Polycitoridae. | ICZN |
| Breviea | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Brevilegnia | Saprolegniales | Dick (2001); Kirk et al. (2008) | Saprolegniaceae. | ICBN |
| Brevilegniella | Leptomitales | Dick (2001); Kirk et al. (2008) | Leptolegniellaceae. | ICBN |
| Brevinema | Spirochaetales | Garrity et al. (2005) | . | ICNB |
| Breviraja | Rajiformes | Nelson (2006) | . | ICZN |
| Brevundimonas | Caulobacterales | Garrity et al. (2005) | . | ICNB |
| Brewcaria | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Brexia | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Brexiella | Celastrales | Mabberley (2008) | Celastraceae. | ICBN |
| Breynia | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Brianhuntleya | Caryophyllales | Mabberley (2008) | Aizoaceae. | ICBN |
| Briareopsis | Alcyonacea | Bayer (1993) | Anthothelidae. | ICZN |
| Briareum | Alcyonacea | Bayer (1981) | Briareidae. | ICZN |
| Briba | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Briceia | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Glandulinidae. | ICZN |
| Brickellia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Brickelliastrum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bridelia | Malpighiales | Mabberley (2008) | Phyllanthaceae. | ICBN |
| Bridgesia | Sapindales | Mabberley (2008) | Sapindaceae. | ICBN |
| Brigantedinium | Peridiniales | Fensome et al. (1993) | Holocene. | ICBN |
| Briggsia | Lamiales | Mabberley (2008); Möller et al. (2011) | Gesneriaceae. Later synonym of Oreocharis. | ICBN |
| Briggsiopsis | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Brighamia | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Brillantaisia | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Brimeura | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Brinkmannia | Reptantia | Gibson (1995) | . | ICZN |
| Brintonia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Briquetia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Briza | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brizalina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bolivinidae. | ICZN |
| Brocchinia | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Brochiella | Stauromedusae | Kramp (1961); Larson & Fautin (1989) | Junior synonym of Manania. | ICZN |
| Brochoneura | Magnoliales | Mabberley (2008) | Myristicaceae. | ICBN |
| Brochothrix | Bacillales | Garrity et al. (2005) | . | ICNB |
| Brodiaea | Asparagales | Mabberley (2008) | Asparagaceae. | ICBN |
| Brodriguesia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brombya | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Bromelia | Poales | Mabberley (2008) | Bromeliaceae. | ICBN |
| Bromeliohyla | Anura | Vitt & Caldwell (2009) | Hylidae. | ICZN |
| Bromeliophila | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Bromeliophrya | Tetrahymenida | Lynn (2008) | . | ICZN |
| Bromeliothrix | Colpodida | Foissner (2010) | . | ICZN |
| Bromheadia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bromidium | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bromuniola | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bromus | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Bronchocoela | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Brongniartella | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Brongniartia | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Brongniartikentia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bronia | Squamata | Vitt & Caldwell (2009) | Amphisbaenidae. | ICZN |
| Bronnimannia | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bronnimanniidae. | ICZN |
| Brookea | Lamiales | Mabberley (2008) | Plantaginaceae. | ICBN |
| Brookesia | Squamata | Vitt & Caldwell (2009) | Chamaeleonidae. | ICZN |
| Brooklawnia | Propionibacteriales | Bae et al. (2006); Ludwig et al. (2012) | . | ICNB |
| Brooklynella | Dysteriida | Lynn (2008) | . | ICZN |
| Brooksia | Salpida | Godeaux (1998) | . | ICZN |
| Brosimum | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Brossardia | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Brothera | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Brotherella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Brotherobryum | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Brotogeris | Psittaciformes | Clements (2007) | . | ICZN |
| Brotomys | Rodentia | Woods & Kilpatrick (2005) | Recently extinct. | ICZN |
| Broughtonia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Broussaisia | Cornales | Mabberley (2008) | Hydrangeaceae. | ICBN |
| Broussonetia | Rosales | Mabberley (2008) | Moraceae. | ICBN |
| Browallia | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Brownea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Browneopsis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Browningia | Caryophyllales | Mabberley (2008) | Cactaceae. | ICBN |
| Brownleea | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Brownlowia | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Brucea | Sapindales | Mabberley (2008) | Simaroubaceae. | ICBN |
| Brucella | Rhizobiales | Garrity et al. (2005) | . | ICNB |
| Brucepattersonius | Rodentia | Musser & Carleton (2005) | . | ICZN |
| Bruchia | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Brugerolleia | Diplomonadida | Brugerolle & Lee (2000) | . | ICZN |
| Brugmansia | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Bruguiera | Malpighiales | Mabberley (2008) | Rhizophoraceae. | ICBN |
| Bruinsmia | Ericales | Mabberley (2008) | Styracaceae. | ICBN |
| Brumimicrobium | Flavobacteriales | Bowman et al. (2003) | . | ICNB |
| Bruneica | Trochamminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Remaneicidae. | ICZN |
| Brunellia | Oxalidales | Mabberley (2008) | Brunelliaceae. | ICBN |
| Brunfelsia | Solanales | Mabberley (2008) | Solanaceae. | ICBN |
| Brunia | Bruniales | Mabberley (2008) | Bruniaceae. | ICBN |
| Brunnera | Boraginales | Mabberley (2008) | Boraginaceae. | ICBN |
| Brunnichia | Caryophyllales | Mabberley (2008) | Polygonaceae. | ICBN |
| Brunonia | Asterales | Mabberley (2008) | Goodeniaceae. | ICBN |
| Brunoniella | Lamiales | Mabberley (2008) | Acanthaceae. | ICBN |
| Brunsvigia | Asparagales | Mabberley (2008) | Amaryllidaceae. | ICBN |
| Brustiospora | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Brya | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bryantella | Clostridiales | Wolin et al. (2003); Wolin et al. (2008) | Later homonym. Replaced by Marvinbryantia. | ICNB |
| Bryanthus | Ericales | Mabberley (2008) | Ericaceae. | ICBN |
| Bryantiella | Ericales | Mabberley (2008) | Polemoniaceae. | ICBN |
| Bryaspis | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Bryceella | Ploima | Segers (2002); Segers (2007) | . | ICZN |
| Brygophis | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Bryhnia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Brylkinia | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Brymela | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Bryoandersonia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryobacter | | Kulichevskaya et al. (2010) | Domain Bacteria - Phylum Acidobacteria. | ICNB |
| Bryobartramia | Encalyptales | Goffinet et al. (2009) | . | ICBN |
| Bryobeckettia | Funariales | Goffinet et al. (2009) | . | ICBN |
| Bryobrittonia | Encalyptales | Goffinet et al. (2009) | . | ICBN |
| Bryobrothera | Hookeriales | Goffinet et al. (2009) | . | ICBN |
| Bryocarpum | Ericales | Mabberley (2008) | Primulaceae. | ICBN |
| Bryocella | Acidobacteriales | Dedysh et al. (2012) | . | ICNB |
| Bryoceuthospora | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Bryochenea | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryochoerus | Echiniscoidea | Kinchin (1994) | . | ICZN |
| Bryocladia | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Bryocrumia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryodelphax | Echiniscoidea | Kinchin (1994) | . | ICZN |
| Bryodes | Lamiales | Mabberley (2008) | Linderniaceae. | ICBN |
| Bryoerythrophyllum | Pottiales | Goffinet et al. (2009) | . | ICBN |
| Bryohumbertia | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Bryolawtonia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryomanginia | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Bryometopus | Bursariomorphida | Lynn (2008); Foissner et al. (2011) | . | ICZN |
| Bryomorphe | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bryonia | Cucurbitales | Mabberley (2008) | Cucurbitaceae. | ICBN |
| Bryonorrisia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryonosema | Microsporida | Canning et al. (2002) | . | ICZN |
| Bryophrya | Colpodida | Lynn (2008); Bourland et al. (2011) | . | ICZN |
| Bryophyllum | Haptorida | Lynn (2008) | . | ICZN |
| Bryopteris | Porellales | Crandall-Stotler et al. (2009) | . | ICBN |
| Bryostreimannia | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Bryotestua | Dicranales | Goffinet et al. (2009) | . | ICBN |
| Bryothamnion | Ceramiales | Schneider & Wynne (2007) | . | ICBN |
| Bryowijkia | Hedwigiales | Goffinet et al. (2009) | . | ICBN |
| Bryoxiphium | Bryoxiphiales | Goffinet et al. (2009) | . | ICBN |
| Bryum | Bryales | Goffinet et al. (2009) | . | ICBN |
| Buarremon | Passeriformes | Clements (2007) | . | ICZN |
| Bubalornis | Passeriformes | Clements (2007) | . | ICZN |
| Bubalus | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Bubaris | Halichondrida | Alvarez & Van Soest (2002) | . | ICZN |
| Bubo | Strigiformes | Clements (2007) | . | ICZN |
| Bubulcus | Ciconiiformes | Clements (2007) | . | ICZN |
| Bucanetes | Passeriformes | Clements (2007) | . | ICZN |
| Buccanodon | Piciformes | Clements (2007) | . | ICZN |
| Buccella | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Trichohyalidae. | ICZN |
| Buccinosphaera | Spumellaria | Anderson et al. (2000) | . | ICZN |
| Bucco | Galbuliformes | Clements (2007) | . | ICZN |
| Bucegia | Marchantiales | Crandall-Stotler et al. (2009) | . | ICBN |
| Bucephala | Anseriformes | Clements (2007) | . | ICZN |
| Bucephalandra | Alismatales | Mabberley (2008) | Araceae. | ICBN |
| Buceros | Coraciiformes | Clements (2007) | . | ICZN |
| Buchanania | Sapindales | Mabberley (2008) | Anacardiaceae. | ICBN |
| Buchenavia | Myrtales | Mabberley (2008) | Combretaceae. | ICBN |
| Buchholzia | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Buchloe | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Buchnera | Enterobacteriales | Garrity et al. (2005) | . | ICNB |
| Buchnera | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Buchneriella | Astomatida | Lynn (2008) | . | ICZN |
| Buchnerina | Lagenida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Ellipsolagenidae. | ICZN |
| Buchnerodendron | Malpighiales | Mabberley (2008) | Achariaceae. | ICBN |
| Buchtienia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Bucinellina | Lamiales | Mabberley (2008) | Gesneriaceae. | ICBN |
| Buckiella | Hypnales | Goffinet et al. (2009) | . | ICBN |
| Buckinghamia | Proteales | Mabberley (2008) | Proteaceae. | ICBN |
| Bucklandiella | Grimmiales | Goffinet et al. (2009) | . | ICBN |
| Buckleya | Santalales | Mabberley (2008) | Santalaceae. | ICBN |
| Buckollia | Gentianales | Mabberley (2008) | Apocynaceae. | ICBN |
| Bucorvus | Coraciiformes | Clements (2007) | . | ICZN |
| Bucquetia | Myrtales | Mabberley (2008) | Melastomataceae. | ICBN |
| Buddenbrockia | Malacovalvulida | Lom & Dyková (2006) | . | ICZN |
| Buddleja | Lamiales | Mabberley (2008) | Scrophulariaceae. | ICBN |
| Budorcas | Cetartiodactyla | McKenna & Bell (1997); Murphy et al. (2001) | Artiodactyla. | ICZN |
| Budvicia | Enterobacteriales | Garrity et al. (2005) | . | ICNB |
| Buehringa | Strombidiida | Lynn (2008) | Later synonym of Strombidium?. | ICZN |
| Bueningia | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Bueningiidae. | ICZN |
| Buergeria | Anura | Vitt & Caldwell (2009) | Rhacophoridae. | ICZN |
| Buergeriella | Pelagica | Gibson (1995) | Bürgeriella. | ICZN |
| Buergersiochloa | Poales | Mabberley (2008) | Gramineae. | ICBN |
| Buetschlia | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Buetschliella | Astomatida | Lynn (2008) | . | ICZN |
| Buetschliellopsis | Astomatida | Lynn (2008) | . | ICZN |
| Buettikoferella | Passeriformes | Clements (2007) | . | ICZN |
| Bufo | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Bufoides | Anura | Vitt & Caldwell (2009) | Bufonidae. | ICZN |
| Bufonia | Caryophyllales | Mabberley (2008) | Caryophyllaceae. | ICBN |
| Bufoniceps | Squamata | Vitt & Caldwell (2009) | Agamidae. | ICZN |
| Buforrestia | Commelinales | Mabberley (2008) | Commelinaceae. | ICBN |
| Bugeranus | Gruiformes | Clements (2007) | . | ICZN |
| Buhoma | Squamata | Vitt & Caldwell (2009) | Serpentes. "Colubridae". | ICZN |
| Buhsea | Brassicales | Mabberley (2008) | Capparaceae. | ICBN |
| Buissonella | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Bukiniczia | Caryophyllales | Mabberley (2008) | Plumbaginaceae. | ICBN |
| Bulbine | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Bulbinella | Asparagales | Mabberley (2008) | Asphodelaceae. | ICBN |
| Bulbocephalus | Eugregarinorida | Perkins et al. (2000) | . | ICZN |
| Bulbophyllum | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bulboplastis | Dixoniellales | Kushibiki et al. (2012) | . | ICBN |
| Bulbostylis | Poales | Mabberley (2008) | Cyperaceae. | ICBN |
| Bulimina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Buliminidae. | ICZN |
| Buliminella | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Buliminellidae. | ICZN |
| Buliminoides | Rotaliida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Buliminoididae. | ICZN |
| Bullanympha | Cristamonadida | Cepicka et al. (2010) | . | ICZN |
| Bulleidia | Erysipelotrichales | Garrity et al. (2005); Ludwig et al. (2009) | . | ICNB |
| Bulleyia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Bullimus | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bullinularia | Arcellinida | Meisterfeld (2000) | Difflugina -- Plagiopyxidae. | ICZN |
| Bulnesia | Zygophyllales | Mabberley (2008) | Zygophyllaceae. | ICBN |
| Bulweria | Procellariiformes | Clements (2007) | . | ICZN |
| Bumilleria | Tribonematales | Ettl (1978) | . | ICBN |
| Bumilleriopsis | Mischococcales | Ettl (1978) | . | ICBN |
| Bunchosia | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Bundleia | Entodiniomorphida | Lynn (2008) | . | ICZN |
| Bungarus | Squamata | Vitt & Caldwell (2009) | Serpentes. Elapidae. | ICZN |
| Bungea | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Bunias | Brassicales | Mabberley (2008) | Cruciferae. | ICBN |
| Bunium | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Bunodactis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bunodeopsis | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bunodes | Actiniaria | Fautin et al. (2007) | Junior homonym, but no replacement name was published. | ICZN |
| Bunodosoma | Actiniaria | Fautin et al. (2007) | . | ICZN |
| Bunolagus | Lagomorpha | McKenna & Bell (1997) | . | ICZN |
| Bunomys | Rodentia | McKenna & Bell (1997) | . | ICZN |
| Bunopithecus | Primates | Groves (2005) | . | ICZN |
| Bunopus | Squamata | Vitt & Caldwell (2009) | Gekkonidae. | ICZN |
| Buphagus | Passeriformes | Clements (2007) | . | ICZN |
| Buphthalmum | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Bupleurum | Apiales | Mabberley (2008) | Umbelliferae. | ICBN |
| Burasaia | Ranunculales | Mabberley (2008) | Menispermaceae. | ICBN |
| Burbidgea | Zingiberales | Mabberley (2008) | Zingiberaceae. | ICBN |
| Burchardia | Liliales | Mabberley (2008) | Colchicaceae. | ICBN |
| Burchellia | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Burckella | Ericales | Mabberley (2008) | Sapotaceae. | ICBN |
| Burdachia | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Burenella | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Burhinus | Charadriiformes | Clements (2007) | . | ICZN |
| Burkartia | Asterales | Mabberley (2008) | Compositae. | ICBN |
| Burkea | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Burkea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Burkholderia | Burkholderiales | Garrity et al. (2005) | . | ICNB |
| Burkillanthus | Sapindales | Mabberley (2008) | Rutaceae. | ICBN |
| Burkilliodendron | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Burlemarxia | Pandanales | Mabberley (2008) | Velloziaceae. | ICBN |
| Burmannia | Dioscoreales | Mabberley (2008) | Burmanniaceae. | ICBN |
| Burmeistera | Asterales | Mabberley (2008) | Campanulaceae. | ICBN |
| Burnatia | Alismatales | Mabberley (2008) | Alismataceae. | ICBN |
| Burnettia | Asparagales | Mabberley (2008) | Orchidaceae. | ICBN |
| Burramys | Australidelphia | McKenna & Bell (1997) | . | ICZN |
| Burretiodendron | Malvales | Mabberley (2008) | Malvaceae. | ICBN |
| Burretiokentia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Bursaopsis | Tintinnida | Lynn (2008) | . | ICZN |
| Bursaria | Bursariomorphida | Lynn (2008) | . | ICZN |
| Bursaria | Apiales | Mabberley (2008) | Pittosporaceae. | ICBN |
| Bursaridium | Bursariomorphida | Lynn (2008) | . | ICZN |
| Bursellopsis | Prorodontida | Lynn (2008) | . | ICZN |
| Burseolina | Buliminida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Cassidulinidae. | ICZN |
| Bursera | Sapindales | Mabberley (2008) | Burseraceae. | ICBN |
| Bursosaphia | Acoela | Dörjes (1968); Faubel & Noreña (2001); Hooge & Tyler (2005) | . | ICZN |
| Bursostoma | Tetrahymenida | Lynn (2008) | . | ICZN |
| Bursulla | Echinosteliopsidales | Olive (1970) | . | ICBN |
| Burtonitethya | Hadromerida | Sarà (2002) | . | ICZN |
| Burtonulla | Clathrinida | Borojevic et al. (2002) | . | ICZN |
| Burttdavya | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Burttia | Oxalidales | Mabberley (2008) | Connaraceae. | ICBN |
| Busarellus | Falconiformes | Clements (2007) | . | ICZN |
| Buschiella | Tintinnida | Lynn (2008) | . | ICZN |
| Bussea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Butastur | Falconiformes | Clements (2007) | . | ICZN |
| Butea | Fabales | Mabberley (2008) | Leguminosae. | ICBN |
| Buteo | Falconiformes | Clements (2007) | . | ICZN |
| Buteogallus | Falconiformes | Clements (2007) | . | ICZN |
| Buthraupis | Passeriformes | Clements (2007) | . | ICZN |
| Butia | Arecales | Mabberley (2008) | Palmae. | ICBN |
| Butomopsis | Alismatales | Mabberley (2008) | Alismataceae. | ICBN |
| Butomus | Alismatales | Mabberley (2008) | Butomaceae. | ICBN |
| Butorides | Ciconiiformes | Clements (2007) | . | ICZN |
| Buttiauxella | Enterobacteriales | Garrity et al. (2005) | . | ICNB |
| Buttonia | Lamiales | Mabberley (2008) | Orobanchaceae. | ICBN |
| Butyricicoccus | Clostridiales | Eeckhaut et al. (2008) | . | ICNB |
| Butyricimonas | Bacteroidales | Sakamoto et al. (2009) | . | ICNB |
| Butyrivibrio | Clostridiales | Garrity et al. (2005) | . | ICNB |
| Buxbaumia | Buxbaumiales | Goffinet et al. (2009) | . | ICBN |
| Buxtehudea | Microsporida | Canning & Vavra (2000) | . | ICZN |
| Buxtonella | Vestibuliferida | Lynn (2008) | . | ICZN |
| Buxus | Buxales | Mabberley (2008) | Buxaceae. | ICBN |
| Buzasina | Lituolida | Loeblich Jr. & Tappan (1988); Loeblich Jr. & Tappan (1992) | Haplophragmoididae. | ICZN |
| Byblis | Lamiales | Mabberley (2008) | Byblidaceae. | ICBN |
| Byrsanthus | Malpighiales | Mabberley (2008) | Salicaceae. | ICBN |
| Byrsonima | Malpighiales | Mabberley (2008) | Malpighiaceae. | ICBN |
| Byrsophyllum | Gentianales | Mabberley (2008) | Rubiaceae. | ICBN |
| Bysmatrum | Peridiniales | Faust & Steidinger (1998) | Now checking. | ICBN |
| Byssophaga | Myxococcales | Garrity et al. (2005) | . | ICNB |
| Byssovorax | Myxococcales | Reichenbach et al. (2006) | . | ICNB |
| Bystropogon | Lamiales | Mabberley (2008) | Labiatae. | ICBN |
| Bythaelurus | Carcharhiniformes | Nelson (2006) | . | ICZN |
| Bythocellata | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Bythophyton | Lamiales | Mabberley (2008) | Linderniaceae. | ICBN |
| Bythotiara | Anthoathecata | Bouillon et al. (2006) | . | ICZN |
| Byttneria | Malvales | Mabberley (2008) | Malvaceae. | ICBN |