Inflorescences: involucral bracts with base cordate or reniform, rarely subtruncate; terminal leaflets light green, margins proximally mostly straight to convex-sided, variously lobed or serrate, variously pubescent. Flowers: sepals (6-)10-20 mm, abaxially usually thinly pubescent; anthers (0.9-)1-1.7 mm. Heads of achenes ovoid to ovoid-cylindric, (9-)11-14 mm diam. 2 n =16.

Flowering summer (Jun-Aug). Dry, rocky, open woods, thickets, river banks; 0-2000 m; Ont., Que.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis., Wyo.

Infrequent to frequent throughout the state. This is a woodland species and is rarely found in the open along roads and railroads. It generally grows in dry soil on wooded slopes and has a decided preference for slopes along streams. The species varies considerably in the length of its stamens and in the size, shape, texture, and color of its sepals. Some of the variations have been given names but after a careful study of my 77 specimens from all parts of the state I have decided that the characters are too variable to be of taxonomic value.