1. Convex on one side and concave on the other with the convexity being greater than the concavity

See also: bulging, convex

• genus Acinonyx
• genus Acinos
• genus Acipenser
• genus Acocanthera
• genus Acokanthera
• genus Aconitum
• genus Acorus
• genus Acridotheres
• genus Acris
• genus Acrobates
• genus Acrocarpus
• genus Acrocephalus
• genus Acroclinium
• genus Acrocomia
• genus Acropora
• genus Acrostichum
• genus Actaea
• genus Actias
• genus Actinia
• genus Actinidia
• genus Actiniopteris
• genus Actinomeris
• genus Actinomyces
• genus Actitis
• genus Adalia