Glabrous, leafy and branching, taprooted annual 4-12 dm; lvs subsessile or short-petiolate, 5-10 cm, once or twice pinnatifid, the ultimate segments linear or lance-linear, 1-4 mm wide; heads numerous, the disk red-purple, 5-12 mm wide; outer invol bracts 2 mm, the inner 5-8 mm, deltoid-oblong or ovate; rays 1-2 cm, yellow, usually red-brown at base; receptacular bracts linear-subulate, attenuate-acuminate, few-striate; disk cors 4-toothed; style-appendages short and blunt; achenes 1-4 mm, wingless or narrowly to broadly winged; pappus obsolete or nearly so; 2n=24. Moist, low places and disturbed sites; primarily c. and s. Great Plains and Tex., e. to Ark. and La., but widely cult., escaped, and irregularly established elsewhere; June-Aug. Ours is var. tinctoria.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.