Cosmos bipinnatus Cav.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Annual 6–20 dm, glabrous or minutely scabrous; lvs sessile or short-petiolate, 6–11 cm, pinnately dissected, the ultimate segments linear or linear-filiform, ca 1 mm wide or less; heads rather numerous, the disk 1–1.5 cm wide; rays ca 8, rose or lilac (white), 1.5–4 cm, often half as wide; achenes 7–16 mm, the body longer than the beak; pappus of 2 or 3 short awns, or none; 2n=24. Native of Mex. and adj. U.S., commonly cult. and casually escaped. Aug.–Oct.