Oenothera pilosella

Species Native to Missouri
Common Name: evening primrose 
Type: Herbaceous perennial
Family: Onagraceae
Native Range: Central North America
Zone: 3 to 8
Height: 1.00 to 2.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June to July
Bloom Description: Yellow
Sun: Full sun
Water: Medium to wet
Maintenance: Low
Suggested Use: Naturalize, Rain Garden
Flower: Showy


Easily grown in average, medium to wet soils in full sun. Can be grown in both moist and dry soils. Prefers slightly acidic, clay soils. Tolerates poor soils, light shade and some drought. Can spread somewhat rapidly, but unwanted plants can be easily removed from the garden due to shallow root systems.

Noteworthy Characteristics

Oenothera pilosella, commonly called prairie sundrops, is a day-flowering member of the evening primrose family. A mat-forming, Missouri native plant which occurs in prairies, fields, wet uplands, wet grassy areas and along roads and railroads. Forms dense, spreading rosettes from which arise erect, leafy stems to 12-18" tall with terminal clusters of 4-petaled, bright yellow, saucer-shaped flowers (to 2" across). Flowers appear in late spring to early summer. No repeat bloom. Flowers are followed by club-shaped seed capsules (to 1" long). Narrow, lance-shaped, stem leaves.

Genus name is unclear but may have come from the Greek words oinos and theras meaning wine-seeker in probable reference to an ancient use of the roots of genus plants in scenting wine.


No serious insect or disease problems. Can be an aggressive spreader.


Effective massed in wild gardens, meadows, cottage gardens, native plant gardens or border fronts.