Bidens polylepis Blake. Phen: Aug-Oct (-Nov). Hab: Marshes, wet meadows, ditches, bogs. Dist: DE, MD, IL, and MO south to GA, AL, FL (?), and TX (and adventive farther north); the pre-Columbian distribution is uncertain, and portions of the eastern range of the species may be only from expansion from a more midwestern distribution.
Origin/Endemic status: Native
Synonymy: = C, FNA21, G, GrPl, GW2, Il, Mi, NE, NY, Oh3, Ok, Pa, RAB, S, SE1, Tn, Va, W; < Bidens aristosa (Michx.) Britton – Ar, K1, K3, K4, NcTx; > Bidens polylepis Blake var. polylepis – F, Sherff & Alexander (1955); > Bidens polylepis Blake var. retrorsa Sherff – F, Sherff & Alexander (1955)