Oenothera perennis L.
Family: Onagraceae
Small Evening-Primrose,  more...
Oenothera perennis image
Paul Rothrock  
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.

©The New York Botanical Garden. All rights reserved. Used by permission.
From Flora of Indiana (1940) by Charles C. Deam
Our specimens from southern Indiana were found in hard, white clay soil and those from the northern part were in a wet, prairie habitat.