Eupatorium altissimum Linnaeus. Phen: Late Aug-Nov. Hab: Woodlands, old fields, woodland borders, and openings over mafic rocks (such as diabase) or calcareous rocks (such as limestone and calcareous sandstone). Dist: CT, NY, QC, MN, and NE, south to Panhandle FL and TX, primarily in the midwest, especially on limestone substrates, and uncommon east of the mountains.
Origin/Endemic status: Native
Syn: = F, G, GrPl, Il, K4, Mi, NcTx, NE, NY, Oh3, Pa, RAB, S, Tn, Tx, Va, W, WV; < Eupatorium altissimum – Ar, C, Fl7, FNA21, K1, K3, SE1, WH3