genus Asplenium
genus Astacus
genus Aster
genus Astilbe
genus Astragalus
genus Astrantia
genus Astreus
genus Astroloma
genus Astronium
genus Astrophyton
genus Astropogon
genus Ateles
genus Athene
genus Atherinopsis
genus Atherurus
genus Athrotaxis
genus Athyrium
genus Atrichornis
genus Atriplex
genus Atropa
genus Attalea
genus Atticus
genus Aucuba
genus Aulacorhyncus
genus Aulostomus
genus Aureolaria
genus Auricularia
genus Auriparus
genus Australopithecus
genus Austrocedrus
genus Austrotaxus
genus Automeris
genus Avahi
genus Avena
genus Averrhoa
genus Avicennia
genus Ayapana
genus Aythya
genus Azadirachta
genus Azolla
genus Babesia
genus Babyrousa
genus Baccharis
genus Bacillus
genus Bacteroides
genus Baiomys
genus Bairdiella
genus Balaena
genus Balaeniceps
genus Balaenoptera
genus Balanus
genus Balistes
genus Ballota
genus Balsamorhiza
genus Bambusa
genus Bankia
genus Banksia
genus Baphia
genus Baptisia
genus Barbarea
genus Barosaurus
genus Bartle-Frere
genus Bartramia
genus Basiliscus
genus Bassariscus
genus Bassia
genus Bathyergus
genus Batis
genus Batrachoseps
genus Bauhinia
genus Beaumontia
genus Begonia
genus Belamcanda
genus Bellis
genus Bemisia
genus Bennettitis
genus Benzoin
genus Berberis
genus Bergenia
genus Beroe
genus Berteroa
genus Bertholletia
genus Bessera
genus Besseya
genus Beta
genus Bettongia
genus Betula
genus Bibos
genus Bidens
genus Bignonia
genus Biscutella
genus Bison
genus Bitis
genus Blaberus
genus Blandfordia
genus Blarina
genus Blastocladia
genus Blastomyces
genus Blatta
genus Blattella
genus Blechnum