Asclepias incarnata subsp. incarnata
Stems 70–150 cm, puberulent in a line with curved trichomes to glabrate. Leaves: petiole 7–15 mm, pilosulous; blade lanceolate to linear-lanceolate, 5–15 × 0.5–4 cm, surfaces sparsely puberulent with curved trichomes, more densely on veins, to glabrate. Peduncles puberulent with curved trichomes to pilosulous, sometimes only on 1 side. Pedicels pilosulous to puberulent with curved trichomes, sometimes only on 1 side. Flowers: corolla bright pink to white; corona pink to white, paler than corolla; anthers green to brown. 2n = 22.
Phenology: Flowering (Apr–)Jun–Sep; fruiting Jul–Nov.
Habitat: Marshes, swamps, creeks, ditches, wet depressions, streamsides, pond edges, sandhills, dolomite, limestone, saturated and sandy soils, riparian woods, mixed hardwood forests, hammocks, wet meadows and prairies, pastures.
Elevation: 0–1700 m.
Distribution
Man., N.B., Ont., Que., Ala., Ariz., Ark., Colo., Conn., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., W.Va., Wis., Wyo., Mexico (Coahuila).
Discussion
Subspecies incarnata is most common west of the Appalachian Mountains and is the only one commonly found in Florida. It has several, disjunct occurrences in wetlands in the Rocky Mountain and Intermountain states and notably along the Snake River in Idaho. It would be interesting to determine whether these occurrences represent relictual populations, recent dispersals (introductions?), or a combination of these. Subspecies incarnata is considered rare in Arizona (Santa Cruz County), Louisiana (Jefferson, LaFourche, St. Charles, Terrebonne, and Vernon parishes), and Montana (Carbon County). Genotypes of this subspecies are the source of several widely available cultivars, including one with pure white flowers.
Selected References
None.