genus Aplysia
genus Apocynum
genus Apodemus
genus Apogon
genus Aporocactus
genus Appendicularia
genus Aptenodytes
genus Apteryx
genus Apus
genus Aquila
genus Aquilegia
genus Ara
genus Arabidopsis
genus Arabis
genus Arachis
genus Aralia
genus Aramus
genus Aranea
genus Araneus
genus Araucaria
genus Araujia
genus Arbutus
genus Arca
genus Arcella
genus Arceuthobium
genus Archaeopteryx
genus Archaeornis
genus Archeopteryx
genus Archidiskidon
genus Archilochus
genus Architeuthis
genus Archosargus
genus Arctictis
genus Arctium
genus Arctocebus
genus Arctocephalus
genus Arctonyx
genus Arctostaphylos
genus Arctotis
genus Ardea
genus Ardisia
genus Areca
genus Arenaria
genus Arenga
genus Arethusa
genus Argemone
genus Argentina
genus Argentinosaurus
genus Argiope
genus Argonauta
genus Argusianus
genus Argynnis
genus Argyranthemum
genus Argyreia
genus Argyrotaenia
genus Argyroxiphium
genus Arilus
genus Ariocarpus
genus Ariomma
genus Arisaema
genus Arisarum
genus Aristolochia
genus Aristotelia
genus Arius
genus Arizona
genus Armadillidium
genus Armeria
genus Armillaria
genus Armillariella
genus Armoracia
genus Arnica
genus Arnoseris
genus Arrhenatherum
genus Artamus
genus Artemia
genus Artemisia
genus Arthropteris
genus Artocarpus
genus Arum
genus Arundinaria
genus Arundo
genus Arvicola
genus Asarum
genus Ascaphus
genus Ascaridia
genus Ascaris
genus Asclepias
genus Ascophyllum
genus Asimina
genus Asio
genus Aspalathus
genus Asparagus
genus Aspergillus
genus Asperula
genus Asphodeline
genus Asphodelus
genus Aspidelaps
genus Aspidiotus
genus Aspidistra
genus Aspidophoroides
genus Aspis