C. virens: annual or biennial; stems erect or ascending, 1 -3 feet high, glabrous or nearly so; leaves linear or lanceolate, toothed or pinnatifid, with triangular or narrow, but short lobes, the upper leaves clasping the stem by pointed spreading auricles; flower-heads small, yellow, in loose, often leafy panicles; involucres often slightly hispid, becoming conical after flowering, the outer bracts narrow-linear, and rather close. - Pastures, dry banks, roadsides, and waste places. Fl. June to September.
C. paludosa: stems erect, scarcely branched, nearly glabrous, 1-2 feet high; leaves ovate, coarsely-toothed, with a few small lobes along the stalk, those of the stem broadly-oblong or lanceolate, pointed, toothed, and clasping the stem by large, pointed auricles; flower-heads yellow, rather large, in corymbs of 8-10, the involucres more or less hairy, with black spreading hairs. - Moist, shady situations. Fl. July to September.