Fibrous-rooted perennial (1-)2-6 dm, usually simple; principal lvs oblanceolate to elliptic, (1-)3-6 cm, obtuse, narrowed to a petiolar base, the bracteal shorter and proportionately narrower, but still well developed and generally exceeding the ovary; infl nodding, the axis straightening during anthesis, the fls becoming erect and opening singly, autogamous, diurnal; hypanthium 3-10 mm; pet 5-10 mm, obcordately notched; filaments 3-4 mm, alternately unequal; anthers 1.5-2.5 mm; style 3-10 mm, about equaling the anthers; fr ellipsoid-clavate or oblong, glandular puberulent (or glabrate in age), the body 4-10 mm, tapering to a short pedicel-like base; 2n=14, a complex heterozygote. Moist or dry soil, fields, meadows, and open woods; Nf., and Que. to s. Man., s. to Va., and Mo., and in the mts. to N.C. and S.C. June-Aug. (O. pumila; Kneiffia pumila; K. perennis)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
