Asclepias decumbens Linnaeus

Stems 45–80 cm. Leaf blades oblanceolate to narrowly elliptic or linear-lanceolate, 4–10 × 0.7–2.7 cm, base cuneate to obtuse, rounded, or subcordate, margins planar, apex acute to obtuse or rounded.

Flowering Apr–Sep(–Oct); fruiting Jul–Oct. Ridges, slopes, plains, bluffs, ditches, fields, streamsides, lake shores, salt marshes, sandhills, limestone, sandy, clay, and rocky soils, oak-hickory, pine, pine-oak, mixed-hardwood, and pine-mixed-hardwood forests, pine flatwoods, pine barrens, forest edges and openings, prairies; 0–800 m; Ont.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Ky., Maine, Md., Mass., Miss., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va.

Subspecies tuberosa is distributed mainly on the Atlantic Coastal Plain, but is occasionally found inland in river valleys east of the Mississippi River. The plants are especially common in eastern and central Tennessee. Sporadic occurrences further inland (for example, in Arkansas, Illinois) may represent introductions. Subspecies tuberosa is uncommon in Rhode Island (Kent County) and is considered to be of conservation concern there.