12a. Cirsium pumilum (Nuttall) Sprengel var. pumilum
Cirsium odoratum (Muhlenberg ex W. P. C. Barton) Petrak
Plants mostly 30–100 cm; branches 3–5+, long. Roots usually slender, not or rarely slightly tuberous-thickened. Leaves usually lobed nearly to midveins, sinuses deep, U-shaped, main spines ± stout, 3–7 mm. Heads 5.5–6 cm. P hyllaries: outer 3–5 mm wide at base, spines stout, 3–6 mm. Corollas usually 40–45 mm. Cypselae usually 3.5–4 mm. 2n = 30.
Flowering summer (Jun–Sep). Fields, pastures, open woods, roadsides; 0–600 m; Conn., Del., Maine, Md., Mass., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Vt., Va., W.Va.
Variety pumilum grows on the Atlantic coastal plain from Maine to South Carolina and ranges inland to Pennsylvania and Ohio. It is known to hybridize with Cirsium horridulum var. horridulum (R. J. Moore and C. Frankton 1966).