Leaves: basal 15-40 × 10-25 cm, blades pinnately compound to 2-pinnatifid; proximal cauline 2-pinnatifid, mid cauline blades 5-11-lobed (distal usually 3-lobed); adaxial faces sparsely to moderately hairy. Receptacles globose to ovoid; paleae 3.1-4.1. Ray laminae 20-45 × 7-12 mm. Discs 15-19 × 10-20 mm. Cypselae 3.5-4 mm; pappi mostly 0.7+ mm. 2n = 72, ca. 72, 102+. Flowering late summer-fall. Wet habitats, along streams and edges of woods; 10-300 m; Conn., Del., Md., Mass., N.H., N.Y., Pa.