Jepson 2012, Kearney and Peebles 1969, McDougal 1973

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Herbaceous and usually low-growing, annuals to perennials, to 1 m tall, stems stout, decumbent or erect, surfaces spongy and peeling with curly to straight, glandular hairs, plants arising from a taproot. Leaves: Alternate, sessile, basal in a loose rosette, diamond-shaped or obovate to oblanceolate, 2-15 cm long, margins entire to pinnately lobed, sometimes lightly sinuate. Flowers: White fading pink with yellow throats, fragrant, large and showy, delicate, opening at dusk, with 4 open and spreading petals with small notches in the tips and rounded lobes, sepals 4, 8-30 mm long, reflexed or with free tips in reddish buds 0-1.2 mm long, hypanthium 20-40 mm long, flowers borne in distal axils with nodding buds, bracted with reduced leaves. Fruits: Loculicidal, cylindric capsules 20-80 mm long, generally curved, and twisted. Seeds obovate with smooth surfaces, 1.5-2 mm long, in 1 row per chamber. Ecology: Found from 1,000-4,000 ft (305-1219 m); flowering February-May. Distribution: Arizona, California, Nevada, Utah; Mexico. Notes: This species tends to be low-growing in Arizona but can get taller under favorable circumstances. A handy key for this species is the length of the tips of the sepals in bud, they are 1-5 mm long in Oenothera flava and less than or to 1 mm long in O. deltoides. Kearney and Peebles list 5 different varieties for this species, ecology and distribution data taken from McDougall. Ethnobotany: Specific uses for this species are unknown, but other species in the genus have uses; compound infusion of plants used as a wash for sore skin, and leaves boiled, fried and often eaten with greens. Synonyms: None Editor: LCrumbacher2012