Leaves: basal 15–40 × 10–25 cm, blades pinnately compound to pinnatifid; proximal and mid cauline blades 5–9-lobed (distal cauline 3-lobed or not lobed); adaxial leaf faces glabrous or sparsely hairy. Receptacles globose to ovoid; paleae 4.4–6.1 mm. Ray laminae 20–45 × 7–18 mm. Discs 15–20 × 10–20 mm. Cypselae 4.2–6 mm; pappi to 0.7 mm. 2n = 36, 54.

Flowering summer–fall. Wet sites, along streams, edges of woods; 10–600 m; Man., N.B., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mich., Minn., Miss., Mo., Nebr., N.H., N.Y., N.C., N.Dak., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis.