Common names: A
- Abraham-Isaac-Jacob
- absinthe
- Abyssinian banana
- acanthus-leaved carline thistle
- achiote
- Adam's laburnum
- adderwort
- Aegean wallflower
- aeonium
- Afghan lilac
- Afghan redbud
- African ansellia
- African daisy
- African feather grass
- African hemp
- African lily
- African linden
- African senna
- African star grass
- African tulip tree
- African violet
- agave
- agrimony
- air potato
- air yam
- Albanian rock rose
- Albany cycad
- alder
- alder buckthorn
- alecost
- Aleppo pine
- Alexandrian senna
- Alfacar sandwort
- Algerian ivy
- Alice sundew
- alkanet
- Allegheny service berry
- almond
- aloe
- alpen rose
- alpine aster
- alpine avens
- alpine balsam
- alpine barrenwort
- alpine buckler fern
- alpine buttercup
- alpine calaminth
- alpine clematis
- alpine clover
- alpine columbine
- Alpine currant
- alpine daphne
- alpine eryngo
- alpine figwort
- alpine fir
- alpine flax
- alpine forget-me-not
- alpine gypsophila
- alpine honeysuckle
- alpine Jerusalem sage
- alpine knotweed
- alpine laburnum
- alpine lady's mantle
- alpine leek
- alpine mint bush
- alpine parsley
- alpine pasque flower
- alpine pennycress
- alpine pink
- alpine poppy
- alpine rose
- Alpine sainfoin
- alpine Saint John's wort
- alpine snowbell
- alpine squill
- alpine strawberry
- alpine toadflax
- alpine water fern
- alpine willow herb
- Altai anemone
- Altai daphne
- alternate-leaved golden saxifrage
- alum root
- aluminum plant
- alumroot
- amaranth
- amaryllis
- Amazon lily
- Amazon water lily
- American feverfew
- American alumroot
- American ash
- American beach grass
- American beech
- American bittersweet
- American bladdernut
- American buckeye
- American cowslip
- American cress
- American dogbane
- American fringe tree
- American honey locust
- American mountain ash
- American pokeweed
- American pussy willow
- American senna
- American skunk cabbage
- American spikenard
- American spindle
- American swamp lily
- American swamp root
- American sweetgum
- American tulip tree
- American vervain
- American winterberry
- American wisteria
- American witch hazel
- American yellow wood
- amethyst eryngo
- Amur honeysuckle
- Amur maple
- Amur pheasant's eye
- Amur pink
- Amur silver grass
- Amur vine
- ananas sage
- anchor plant
- Andalusian dutchman's pipe
- anemone
- anemone clematis
- anemone-flowered dahlia
- angel hair
- angel's tears
- angel's trumpet
- angelica
- anise
- anise hyssop
- anise tree
- anise-scented sage
- aniseed
- annatto
- annual betony
- annual candytuft
- annual honesty
- annual phlox
- annual ragweed
- annual sage
- annual tree mallow
- Antarctic beech
- Antwerp hollyhock
- Apache plume
- apple
- apple mint
- apple of Peru
- apple rose
- apricot
- apricot sprite hyssop
- Arabian jasmine
- aralia
- arbor vitae
- arborvitae
- archangel
- arctic chrysanthemum
- Arctic rose
- Arends' azalea
- Argentine senna
- Arizona cypress
- Armenian cranesbill
- Armenian grape hyacinth
- Armenian mallow
- Armenian pasque flower
- arnica
- Arolla pine
- arrow bamboo
- arrow-jointed broom
- arrowhead
- artichoke
- artillery plant
- arum
- arvensis rose
- asafetida
- asafoetida
- ash
- ash-leaved maple
- Ashby's banksia
- ashy cranesbill
- Asian globeflower
- Asian pear
- Asian rice
- Asian skunk cabbage
- Asian wild apple
- asiatic lily
- asparagus fern
- asparagus pea
- aspen
- aspen fleabane
- asphodel
- aster
- aster of Pyrenees
- astilbe
- Atlantic ivy
- atlantic ninebark
- Atlas cedar
- Atlas fescue
- aubergine
- aubrieta
- August lily
- auricula
- Australian blackwood
- Australian chessewood
- Australian dahlia
- Australian flame tree
- Australian indigo
- Australian tree fern
- Australian violet
- Australian water lily
- Austrian black pine
- Austrian copper briar
- Austrian mountain ash
- Austrian sage
- Austrian speedwell
- Austrian whitebeam
- autumn catchfly
- autumn cherry
- autumn crocus
- autumn daffodil
- autumn moor grass
- autumn olive
- autumn pheasant's eye
- autumn sage
- avens
- azalea
- Azores buttercup
- Aztec sweet herb