- abaxial
- abortifacient
- abscission
- accessory buds
- accrescent
- achene
- acicular
- acroscopic
- actinomorphic
- aculeate
- acuminate
- acute
- adaxial
- adnate
- adpressed
- adventitious
- aerenchym
- ala
- aliform
- alkaloid
- allelopathy
- allopatric
- allopolyploid
- alluvial
- alluvium
- alternate
- amphidiploid
- amplexicaul
- anaemia
- analeptic
- analgesic
- anastomose
- andesite
- andosol
- androecium
- androgynophore
- androphore
- anemophilous
- aneuploid
- annual
- anthelmintic
- anther
- anthesis
- anticlinal
- antrorse
- apertures
- apetalous
- apex
- aphrodisiac
- apical
- apiculate
- apomict
- apomixis
- applanate
- appressed
- arborescent
- arcuate
- areole
- aril
- arillode
- arilloid
- aristate
- armed
- arris
- arthritis
- articulated
- ascending
- asexual
- astringent
- atonic
- attenuate
- auct.
- auricle
- auriculate
- auriform
- autopolyploid
- auxin
- axil
- axillary
- axis