Cleome serrulata Pursh
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stems 5–8 dm, branched above, pale, glabrous or nearly so; petioles not spiny; lfls 3, narrowly lanceolate, 3–6 cm, sharply acuminate or cuspidate, entire, glabrous at maturity, sometimes finely and sparsely villosulous when young; bracts crowded, lanceolate, short-petioled; pet subequally disposed, pink (white), oblong, 1 cm, the blade narrowed to the base and much exceeding the claw; fr torulose, 3–5 cm, glabrous, the stipe 1.5–2 cm, about equaling the pedicel; 2n reputedly =32, 34, 60. Prairies; Ind. to Mo. and Minn., w. to Sask., Wash., Calif., and Tex. July, Aug.