Asclepias verticillata Linnaeus. Whorled Milkweed. Phen: (Apr-) May-Sep; Sep-Oct. Hab: Barrens, thin soils of rock outcrops (especially mafic or calcareous rocks), open woodlands, longleaf pine sandhills, pine flatwoods, road and powerline rights-of-way. Dist: E. MA west to ND and MB, south to s. FL, TX, NM, and AZ.
Origin/Endemic status: Native
Syn: = Ar, C, F, Fl5, G, GrPl, Il, K1, K3, K4, Mi, Mo2, NcTx, NE, NY, Ok, Pa, RAB, S, Tn, Tx, Va, W, WH3, Woodson (1954)