Plants 50-100 cm (weakly rhizomatous). Stems angulate. Basal leaves: blades broadly elliptic, to 17 cm, margins entire or sinuate. Cauline leaves: proximal (and mid) petiolate, elliptic (bases rounded), margins entire or serrulate; distal petiolate or sessile, smaller (narrower). Involucres (9.5-)10-12(-14) mm. Phyllaries (pale green) ovate, midvein wings uniform or highest at apices. Corollas white or greenish, 8-10(-11.5) mm. Cypselae fusiform or clavate, 4-5 mm (dark brown, 12-15-ribbed); pappi (6-)7-8(-9) mm. 2n = 54. Flowering May (south)-Aug (north). Wet prairies and pastures, usually in boggy areas in north; 0-600 m; Ont.; Ala., Ark., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Miss., Mo., Nebr., Ohio, Okla., S.Dak., Tenn., Tex., Wis.