Oenothera biennis

Common evening-primrose

Family: Onagraceae · Type: biennial · Not Native

Common evening-primrose is a naturalized biennial found in northwestern, central western, and southwestern California in disturbed places at elevations generally below 300 meters. Flowering from June to September, this plant produces bright yellow flowers that fade to a duller orange, with each blossom reaching 10 to 25 millimeters long. Growing with erect stems 30 to 200 centimeters tall that have glandular hairs and a distinctive rosette form, it spreads with spreading, strigose growth habit. Its cauline leaves are 5 to 20 centimeters long, oblanceolate to elliptic, with margins that are nearly entire to dentate and sometimes slightly lobed toward the base. The fruit is a cylindrical capsule 20 to 40 millimeters long, containing small, irregularly pitted seeds.

Habitat: Disturbed places

Bloom period: Jun-Sep

Elevation: generally < 300 m

Bioregions: NW, CW, SW

California counties: Riverside, San Bernardino, Sutter, El Dorado, Sacramento, Contra Costa, Los Angeles, San Luis Obispo, Mariposa

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.