Aquilegia canadensis
Arabis
Aralia spinosa
Arctatis caroliniana
Arethusa parviflora
Aristoloichia serpentaria, 3 sp.
Arum sagittæfolium and triphyllum
Arundo tecto
Asarum virginicum
Aselepias purpurascens, variegata, verticillata and others, tuberosa