Adam's laburnum Laburnocytisus adamii
Afghan ash Fraxinus xanthoxyloides
African olive tree Olea europaea africana
Ailanthus Ailanthus
Alabama snow wreath Neviusia alabamensis
Alabanian forsythia Forsythia europaea
Alangium Alangium
Alaternus Rhamnus alaternus
Albizia Albizia
Alder Alnus
Alder buckthorn Rhamnus frangula
All-saints cherry Prunus fruticosa
Allspice Calycanthus fertilis
Almond cherry Prunus glandulosa
Almond tree Prunus dulcis
Almond-leaved willow Salix triandra
Alpine currant Ribes alpinum
Alpine elder Sambucus racemosa
Alpine honeysuckle Lonicera alpigena
Alpine laburnum Laburnum alpinum
Alpine willow Salix glabra
Alternate-leaf dogwood Cornus alternifolia
Alumroot Heuchera
Amber tree Liquidambar formosana
American alder Sambucus canadensis
American beech Fagus grandifolia
American elderberry Sambucus canadensis
American green alder Alnus viridis ssp. Crispa
American hazel Corylus americana
American holly Ilex opaca
American hornbeam Ostrya virginiana
American lime Tilia americana
American linden Tilia americana
American mountain ash Sorbus americana
American olive Osmanthus americanus
American persimmon Diospyros virginiana
American red gum Liquidambar styraciflua
American sweet gum Liquidambar styraciflua
American white oak Quercus lyrata
Amur cork tree Phellodendron amurense
Amur linden Tilia amurensis
Amur maackia Maackia amurensis
Andormeda Andromeda
Angelica tree Aralia spinosa
Anise magnolia Magnolia salifolia
Anise tree Illicium
Antarctic beech Nothofagus antarctica
Apple Malus
Apple-leaved willow Salix hastata
Aralia Aralia
Armenian oak Quercus pontica
Aromatic wintergreen Gaultheria
Aron's beard Cotinus coggygria
Arve Pinus cembra
Ash Fraxinus
Ash-leaved maple Acer negundo
Aspen Populus tremula
Atsuki pear Sorbus alnifolia
Aucuba Aucuba
Autumn cherry Prunus subhirtella 'Autumnalis'
Avens Geum
Azara Azara
Azores holly Ilex perado