Perennial, spreading by creeping roots; stem erect, 3-8 dm, with white bark exfoliating below, glabrous below, minutely glandular-puberulent in the infl; lvs linear to linear-oblong, 2-8 cm, acute, entire or nearly so, tapering to the base, glabrous above, puberulent with incurved hairs beneath; fls sessile in the upper axils, malodorous, nodding in bud; hypanthium 2.5-4 cm; sep at anthesis connivent, unilaterally reflexed or spreading; pet white, turning pink, 1.5-2.5 cm; stamens equal; fr linear-oblong, 1-3 cm, minutely glandular, shallowly 4-sulcate; seeds in 1 row in each locule; 2n=14, 28. Prairies and plains; Wis. to Alta., s. to Kans. & Colo. June, July. (Anogra n.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.