Leaf blades oblong to obovate or spatulate, 25-65+ × 8-25+ mm, coarsely 1-pinnate or not lobed, ultimate margins dentate or entire. Ray corollas golden yellow, laminae oblong-ovate, 8-20 mm. Ray cypselae weakly triquetrous, 2.5-3 mm, obscurely, if at all, winged, lateral faces 2-ribbed, abaxial faces 3-ribbed; disc cypselae ± compressed-columnar, 2-3 mm, 10-ribbed, not winged. 2n = 18. Flowering Apr-Aug(-Oct). Disturbed sites; 0-100 m; introduced; Ala., Alaska, Calif., Conn., La., Maine, Mass., N.Y., N.C., Ohio, Oreg., Pa., S.C.; Eurasia; n Africa.
Glabrous annual 2-6 dm; lvs oblong to ovate or the lower spatulate, coarsely and sharply toothed or irregularly pinnatifid, the lower subpetiolate, the others sessile and clasping, to 6 נ2 cm; heads few, terminating the branches, the disk 1-2 cm wide; rays 10-20, yellow, 8-15 mm; disk-achenes subterete and ca 10-ribbed; ray-achenes flattened and with 2 wing-angles; 2n=18. Fields and waste places; native of the Old World, occasionally intr. in our range. June-Oct.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.