Stems 6-15 dm, sparingly branched; lvs ovate-oblong, the lower to 2 dm, thrice pinnately compound, with narrowly oblong ultimate segments; upper lvs once or twice compound with linear segments 1-3 cm, the uppermost lvs often simple; rays 7-14; pet white; fr broadly ovate to suborbicular, 3-5 mm; 2n=40. Moist prairies and open woods; Mo., se. Kans., and n. Ark. to Ill., O., Ky., Tenn., and Ala. May, June. (Eulophus a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.