Camissoniopsis bistorta
California sun cup
(c) Millie Basden, some rights reserved (CC BY) · licence
Family: Onagraceae · Type: Perennial · Native
Camissoniopsis bistorta (California sun cup) is a native California perennial in the Onagraceae family, recognized by robust perennial habit and large, thick, 4-angled fruits.
California sun cup is a native perennial found in southwestern California's sandy coastal fields and grassland openings at elevations below 600 meters. Flowering from March to June, this plant produces yellow flowers with delicate petals 7 to 15 millimeters long and often featuring 1 to 2 basal spots. Growing with decumbent to ascending stems 50 to 80 centimeters tall that peel and are covered in strigose or spreading hairs, it develops a rosetted form. Its leaves range from 12 to 120 millimeters long, generally lanceolate or linear, with minute teeth or nearly smooth edges. The fruit is distinctively slender, measuring 12 to 40 millimeters long and slightly twisted or wavy.
Identification and appearance
Key characters: 11 sympatric species; distinguished by robust perennial habit and large, thick, 4-angled fruits
Habitat and range
Habitat: Sandy fields near coast or clay soils in grassland to openings in coastal-sage scrub or chaparral
Elevation: < 600 m
California counties: San Diego, Ventura, San Bernardino, Orange, Riverside, Los Angeles, San Luis Obispo, Kern, Inyo, Santa Barbara
Outside California: northern Baja California
Bloom period
Camissoniopsis bistorta blooms Mar-Jun.
How to tell it apart
vs Camissonia: Camissoniopsis flowers from base with four-angled fruits; Camissonia flowers from top with round fruits.; vs Oenothera: Camissoniopsis has four-angled fruits; Oenothera has round fruits and a distinctive 4-lobed cross-shaped stigma.; vs Taraxia: Camissoniopsis has four-angled fruits and flowers from base; Taraxia has round fruits.; vs Tetrapteron: Camissoniopsis has four-angled fruits; Tetrapteron has four-winged fruits.; vs Eulobus: Camissoniopsis has four-angled fruits; Eulobus has wand-like stems with red-flecked petals.
Frequently asked questions
Is Camissoniopsis bistorta native to California?
Yes. Camissoniopsis bistorta is native to California (recorded as native).
When does Camissoniopsis bistorta bloom?
Camissoniopsis bistorta blooms Mar-Jun.
Where in California does Camissoniopsis bistorta grow?
Camissoniopsis bistorta occurs in San Diego, Ventura, San Bernardino, Orange, Riverside, Los Angeles, San Luis Obispo, Kern and other counties, at elevations of < 600 m.
What plant family does Camissoniopsis bistorta belong to?
Camissoniopsis bistorta is in the Onagraceae family, genus Camissoniopsis.
What habitat does Camissoniopsis bistorta grow in?
Camissoniopsis bistorta grows in Sandy fields near coast or clay soils in grassland to openings in coastal-sage scrub or chaparral.
Related species
Other California species in the same genus, family, or bioregion.
- Camissoniopsis cheiranthifolia — Beach evening-primrose
- Camissoniopsis cheiranthifolia subsp. cheiranthifolia
- Camissoniopsis cheiranthifolia subsp. suffruticosa
- Camissoniopsis confusa — San bernardino sun cup
- Camissoniopsis guadalupensis subsp. clementina — San clemente island evening-primrose
- Camissoniopsis hardhamiae — Hardham's evening-primrose
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.