Oenothera pilosella Rafinesque. Phen: May-Jul. Hab: Fens, marshes, swamps, moist fields, disturbed areas. Dist: NH west to ON, south to s. VA, KY, n. AL, c. MS, and c. LA; widely cultivated, many occurrences eastward and southward likely represent introductions.
Origin/Endemic status: Native
Taxonomy Comments: O. sessilis (Pennell) Munz, treated by Straley (1977) as O. pilosella ssp. sessilis (Pennell) Straley, is best recognized as a species; it is restricted to West Gulf Coastal Plain.
Synonymy: = F, FNA10, G, Il, K4, Mi, Pa, Tn, Va, WV, Munz (1965); = Oenothera fruticosa L. var. hirsuta Nutt. ex Torr. & A.Gray; = Oenothera pilosella Raf. ssp. pilosella – Ar, C, K1, K3, NE, NY, Straley (1977), Wagner, Hoch, & Raven (2007); > Kneiffia pratensis Small – S