Distribution: Occurring east of the Cascades crest, where known historically from the south-central area. Washington to California, east to the Rocky Mountains and Great Plains.
Habitat: Hard-packed soil in swales or around vernal pools in the plains and lower foothills.
Flowers: July-August
Origin: Native
Growth Duration: Perennial
Conservation Status: Historical in Washington (WANHP)
Pollination: Bees, moths
Tufted, acaulescent, sub-glabrous perennial.
Leaves basal, in rosettes, oblanceolate, 5-20 cm. long and up to 15 mm. broad, the lower third pinnatifid with backward-angled lobes, the upper portion entire or wavy-dentate.
Flowers sessile; calyx tube purplish, slender, 2-12 cm. long, the 4 lobes reflexed, free or partly fused and turned to one side; petals 10-20 mm. long, yellow, aging to purplish; stamens 8; stigma with 4 linear lobes 3 mm. long; ovary inferior, 4-celled.
Capsule woody, ovoid, 10-20 cm. long, conspicuously winged.
PNW Herbaria: Specimen records of Oenothera flava in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Oenothera flava checklist entry
OregonFlora: Oenothera flava information
E-Flora BC: Oenothera flava atlas page
CalPhotos: Oenothera flava photos