genus Aerobacter
genus Aeschynanthus
genus Aesculus
genus Aethionema
genus Aethusa
genus Aetobatus
genus Aframomum
genus Afrocarpus
genus Afropavo
genus Agalinis
genus Agama
genus Agapanthus
genus Agapornis
genus Agaricus
genus Agastache
genus Agathis
genus Agave
genus Agdestis
genus Agelaius
genus Ageratina
genus Ageratum
genus Agkistrodon
genus Aglaomorpha
genus Aglaonema
genus Agonus
genus Agrimonia
genus Agriocharis
genus Agrobacterium
genus Agropyron
genus Agrostemma
genus Agrostis
genus Ailanthus
genus Ailuropoda
genus Ailurus
genus Aix
genus Ajaia
genus Ajuga
genus Alauda
genus Albatrellus
genus Albizia
genus Albizzia
genus Albuca
genus Albugo
genus Albula
genus Alca
genus Alcea
genus Alcedo
genus Alcelaphus
genus Alces
genus Aldrovanda
genus Alectis
genus Alectoria
genus Alectoris
genus Alectura
genus Alepisaurus
genus Aletris
genus Aleurites
genus Aleyrodes
genus Algeripithecus
genus Alisma
genus Allamanda
genus Alliaria
genus Alligator
genus Allionia
genus Allium
genus Allosaurus
genus Alnus
genus Alocasia
genus Aloe
genus Alopecurus
genus Alopex
genus Alopius
genus Alosa
genus Alouatta
genus Alpinia
genus Alsobia
genus Alsophila
genus Alstonia
genus Alstroemeria
genus Alternanthera
genus Althaea
genus Alyssum
genus Alytes
genus Amanita
genus Amaranthus
genus Amaryllis
genus Amauropelta
genus Amazona
genus Amberboa
genus Ambloplites
genus Amblyrhynchus
genus Ambrosia
genus Ambystoma
genus Ameiurus
genus Amelanchier
genus Amia
genus Amianthum
genus Ammobium
genus Ammodytes
genus Ammotragus
genus Amoeba