Asclepias incarnata Linnaeus var. incarnata . Western Swamp Milkweed. Phen: Jul-Sep; Aug-Oct. Hab: Swamps, marshes, especially over calcareous substrates, such as limestone or calcareous shale. Dist: ME and s. QC west to MB, south to VA, s. TN (Chester, Wofford, & Kral 1997), AR, TX, and CO; disjunct in TX, NM, and UT.
Origin/Endemic status: Native
Syn: = C, F, G, GW2, NE, Tx, Va; = Asclepias incarnata – S; = Asclepias incarnata ssp. incarnata – Ar, K1, K3, K4, Mo2, NcTx, NY, Pa, RAB, Tn, W, Woodson (1954); < Asclepias incarnata – Fl5, GrPl, Il, Mi, WH3