Occurring from the Ozark region to n. Mex., probably does not reach our range. It is smaller in all respects than P. grandiflora; the fls have ca 10-15(-30) stamens, and red-purple pet 5-8 mm.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.