Oenothera triloba Nutt.

Winter-annual to biennial or short-lived perennial from a stout taproot, nearly stemless; lvs oblanceolate, 1–2 dm, runcinate-pinnatifid, often nearly to the midvein; fls axillary, the earliest sessile, the later ones on stout pedicels to 1 cm; hypanthium slender, 3–10 cm; sep lanceolate, 10–18 mm, reflexed, usually unilaterally so and connivent; pet obovate, 1–2.5 cm, pale yellow, drying whitish; stamens alternately unequal; fr hard, woody, long-persistent, ellipsoid or obovoid, 1–2 cm, the 4 wings each with a lateral tooth or angle. Dry woods, barrens, and prairies; Ky. and Tenn. to Kans. and Tex. May, June. (Lavauxia t.)