- abele
- absorbent
- acarpous
- acaulesent
- accrete
- acervate
- abelmosk
- abutilon
- acacia
- acaulose
- acarpellous
- acauline
- acaulous
- accrescent
- acerose
- achene
- achlamydeous
- acerous
- acotyledonous
- acrocarpous
- acrogenous
- acrospore
- aconite
- acorn
- acotyledon
- aculeate
- acumen
- acuminate
- adder-spit
- adiantum
- adonis
- adventitious
- agaric
- agaricaceous
- agave
- aglet
- ailanthus
- aiglet
- akene
- albumen
- alder
- aleuron
- aleurone
- alga
- algae
- allogamy
- alfalfa
- alliaceous
- alligator pear
- allseed