Triosteum perfoliatum Linnaeus. Perfoliate Horse-gentian. Phen: Late May-early Jun; Aug-Oct. Hab: Woodlands and forests in circumneutral soils, particularly those over mafic or calcareous rocks. Dist: MA west to MN, south to n. SC, n. GA (Jones & Coile 1988), and OK.
Origin/Endemic status: Native
Syn: = Ar, C, F, Il, K1, K3, K4, Mi, Mo2, NE, NY, Pa, RAB, S, Tn, Va, W, WV, Ferguson (1966a); = Triosteum perfoliatum L. var. perfoliatum – G, GrPl