Erect, 5-20 dm, the stem glaucous and glabrous or nearly so; lvs glabrous to rather thinly strigose, palmately deeply cleft into 5-10 finger-like segments that may be again cleft; stipules slender, 6-8 mm, caducous; infl an open panicle, the fls long-pedicellate, all perfect; epicalyx wanting; cal, carpels, and usually the pedicels glabrous or nearly so; sep-tips connivent in bud, forming a short beak; pet red to purple with a basal white spot, 18-31 mm, erose-denticulate to fimbriate across the top; mature carpels indurate, rugose-reticulate; 2n=28. Limestone glades and rocky prairies; Ozarkian, mainly in sw. Mo., nw. Ark., and adj. Kans. and Okla., but locally intr. along railroads in Clay Co., Mo. May-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.