Lvs numerous, ensiform, to 7 dm; stem strongly zigzag, often decumbent, 2-4 dm, conspicuously shorter than the lvs; fls 8-10 cm wide, light violet to lavender; sep with a white-variegated area at the base of the ovate blade around the yellow papillose crest, the claw as long as the blade, greenish-white with green veins; pet oblanceolate to spatulate; fr ovoid to ellipsoid-ovoid, indehiscent; 2n=42. Swamps, low woods, and shores; O. and e. Kans. to La. and Ky. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species, as I have found it, is restricted to low, overflow land along streams and to the slopes of overflow terraces and slopes bordering streams, ponds, and sloughs. It will, no doubt, be found in suitable habitats along all of our principal streams. Where it becomes established, it usually forms large colonies.