• Achlys californica Fukuda & Baker
• Achlys triphylla (Sm.) DC.
• Aconitum anthora Linnaeus
• Aconitum bicolor J.A. Schultes
• Aconitum bulbiferum T.J. Howell accepted as Aconitum columbianum Nutt.
• Aconitum carmichaelii Debeaux
• Aconitum columbianum Nutt.
• Aconitum delphinifolia De Candolle
• Aconitum delphiniifolium DC.
• Aconitum ferox Wallich ex Ser.
• Aconitum fischeri Reichb.
• Aconitum geranioides Greene accepted as Aconitum columbianum Nutt.
• Aconitum hansenii Greene accepted as Aconitum columbianum Nutt.
• Aconitum howellii A. Nels. & J.F. Macbr. accepted as Aconitum columbianum Nutt.
• Aconitum infectum Greene
• Aconitum leibergii Greene accepted as Aconitum columbianum Nutt.
• Aconitum lycoctonum Linnaeus
• Aconitum maximum Pallas ex DC.
• Aconitum mogollonicum Greene accepted as Aconitum columbianum Nutt.
• Aconitum napellus Linnaeus
• Aconitum nivatum A. Nels. accepted as Aconitum delphiniifolium DC.
• Aconitum noveboracense Gray ex Coville
• Aconitum reclinatum Gray
• Aconitum uncinatum Linnaeus
• Aconitum variegatum Linnaeus
• Aconitum viviparum Greene accepted as Aconitum columbianum Nutt.
• Aconitum vulparia Reichb. ex Sprengel
• Actaea alba auct. non (L.) P. Mill. accepted as Actaea pachypoda Ell.
• Actaea arguta Nutt. accepted as Actaea rubra (Ait.) Willd.
• Actaea dioica Walter accepted as Aruncus dioicus (Walter) Fernald
• Actaea ludovici Boivin
• Actaea pachypoda Ell.
• Actaea rubra (Ait.) Willd.
• Actaea spicata Linnaeus
• Adlumia fungosa (Ait.) Greene ex B.S.P.
• Adonis aestivalis Linnaeus
• Adonis aestivalis Linnaeus
• Adonis annua Linnaeus
• Adonis autumnalis Linnaeus accepted as Adonis annua Linnaeus
• Adonis vernalis Linnaeus
• Akebia pentaphylla (Makino) Makino
• Akebia quinata (Houtt.) Dcne.
• Anemone acutiloba (DC.) G. Lawson accepted as Hepatica nobilis Schreb.
• Anemone adamsiana Eastw. accepted as Anemone oregana Gray
• Anemone americana (DC.) Hara accepted as Hepatica nobilis Schreb.
• Anemone berlandieri Pritz.
• Anemone blanda Schott & Kotschy
• Anemone canadensis Linnaeus
• Anemone caroliniana Walt.
• Anemone coronaria Linnaeus
• Anemone cylindrica Gray
• Anemone decapetala auct. non Ard. accepted as Anemone berlandieri Pritz.
• Anemone deltoidea Hook.
• Anemone dodecaphylla Krock. (unaccepted)
• Anemone drummondii S. Wats.
• Anemone edwardsiana Tharp
• Anemone felix M.E. Peck accepted as Anemone oregana Gray
• Anemone globosa (Torr. & Gray) Nutt. ex Pritz. accepted as Anemone multifida Poir.
• Anemone grayi Behr & Kellogg accepted as Anemone oregana Gray
• Anemone hepatica Linnaeus accepted as Hepatica nobilis Schreb.
• Anemone heterophylla Nutt. ex Torr. & Gray accepted as Anemone berlandieri Pritz.
• Anemone heterophyllum accepted as Anemone berlandieri Pritz.
• Anemone hudsoniana (DC.) Richards. accepted as Anemone multifida Poir.
• Anemone hupehensis (hort. ex Lem.) Lem. ex Boynton
• Anemone hupehensis (Lem. & Lem.) Lem. & Lem.
• Anemone lancifolia Pursh
• Anemone lithophila Rydb.
• Anemone ludoviciana Nutt. accepted as Pulsatilla patens (L.) P. Mill.
• Anemone lyallii Britt.
• Anemone minima DC. accepted as Anemone quinquefolia Linnaeus
• Anemone multiceps (Greene) Standl.
• Anemone multifida (Pritz.) Zamels accepted as Pulsatilla patens (L.) P. Mill.
• Anemone multifida Poir.
• Anemone narcissiflora Linnaeus
• Anemone narcissiflora Linnaeus
• Anemone nemorosa Linnaeus
• Anemone nuttalliana DC. accepted as Pulsatilla patens (L.) P. Mill.
• Anemone occidentalis S. Wats. accepted as Pulsatilla occidentalis (S. Wats.) Freyn
• Anemone okennonii Keener & Dutton accepted as Anemone tuberosa Rydb.
• Anemone oregana Gray
• Anemone parviflora Michx.
• Anemone piperi Britt. ex Rydb.
• Anemone pulsatilla Linnaeus accepted as Pulsatilla vulgaris Miller
• Anemone quinquefolia Linnaeus
• Anemone ranunculoides Linnaeus
• Anemone richardsonii Hook.
• Anemone riparia Fern. accepted as Anemone virginiana Linnaeus
• Anemone stylosa A. Nels. accepted as Anemone multifida Poir.
• Anemone tetonensis Porter ex Britt.
• Anemone trifolia auct. non L. accepted as Anemone lancifolia Pursh
• Anemone tuberosa Rydb.
• Anemone virginiana Linnaeus
• Anemone zephyra A. Nels. (unaccepted)
• Anemonella thalictroides (L.) Spach accepted as Thalictrum thalictroides (L.) Eames & Boivin
• Anemonidium canadense (L.) A. & D. Löve accepted as Anemone canadensis Linnaeus
• Anemonidium nemorosum (L.) Holub accepted as Anemone nemorosa Linnaeus
• Anomospermum excelsum Dalzell accepted as Actephila excelsa (Dalzell) Müll. Arg.
• Aquilegia australis Small accepted as Aquilegia canadensis Linnaeus
• Aquilegia barnebyi Munz
• Aquilegia brevistyla Hook.