Leaves: petioles 3-12+ cm, blades 10-35(-60+) × 10-35+ cm, larger usually 3-5-lobed. Ray laminae 12-30+ mm. Cypselae 5-6 mm. 2n = 32. Flowering Jun-Aug(-Oct). Thickets, forest margins, often wet sites; 10-300+ m; Ala., Ark., Del., D.C., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mich., Miss., Mo., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.; introduced in Bermuda. B. L. Turner (1988) included types of Smallanthusuvedalia and S. maculatus (Cavanilles) H. Robinson within a single species circumscription. If that circumscription is accepted, the range of S. uvedalia extends through eastern Mexico and Central America to Panama.
Coarse perennial 1-3 m, the stem glandular or spreading- hairy beneath the heads, otherwise generally glabrous; lvs large, sometimes over 3 dm, deltoid-ovate, subpalmately lobed and veined, scabrous-hispid to subglabrous above, more finely hairy and often glandular beneath, with broadly winged, sometimes runcinate petiole; heads in moderately open, leafy cymes, the bright yellow disk ca 1.5 cm wide; invol bracts lance-ovate to ovate or elliptic, leafy, 1-2 cm, much broader and generally longer than the outer receptacular bracts; rays ca 8-11, bright yellow, 1-2(-3) cm, rarely reduced and inconspicuous; achenes ca 6 mm, impressed-striate (or shallowly ribbed and grooved), with many nerves; 2n=32. Woods and meadows; N.Y. to Ill. and Mo., s. to Fla. and Tex. July-Sept.(Smallanthus u.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.