Eremothera boothii
Booth's sun cup
Photo by Chez Brungraber
Family: Onagraceae · Type: Herb · Native
Eremothera boothii (Booth's sun cup) is a native California herb in the Onagraceae family.
Booth's sun cup is a California native annual found in rocky or sandy habitats at moderate elevations. Flowering from March to June, this plant produces white to red-tinged flowers small to 7.5 millimeters long, with a distinctively nodding inflorescence. Growing with generally red-tinted erect stems that peel and have sparse minute hairs, it develops a sparse or occasionally well-developed rosette. Its leaves are lanceolate to narrowly elliptic, sparsely toothed, with proximal leaves sometimes oblanceolate or absent. The fruit is notable for being 8 to 35 millimeters long, cylindric, and curved or twisted, with seeds that vary from pale to dark brown.
Habitat and range
California counties: Inyo, San Bernardino, Imperial, Riverside, Kern, San Benito, San Luis Obispo, Santa Barbara, San Diego, Monterey, Tulare, Los Angeles, Stanislaus, Fresno, Ventura
How to tell it apart
vs Chylismia: Eremothera has white/pink flowers opening at night; Chylismia has yellow day flowers.; vs Chorizanthe: Eremothera has regular 4-petaled flowers; Chorizanthe has tiny flowers in papery involucres (buckwheat family).; vs Oenothera: Eremothera has white/pink flowers; Oenothera typically has yellow flowers with 4-lobed stigma.; vs Camissonia: Eremothera has white/pink night flowers; Camissonia has yellow day flowers.; vs Gayophytum: Eremothera has larger white/pink flowers; Gayophytum has tiny thread-like stems and minute flowers.
Frequently asked questions
Is Eremothera boothii native to California?
Yes. Eremothera boothii is native to California (recorded as native).
Where in California does Eremothera boothii grow?
Eremothera boothii occurs in Inyo, San Bernardino, Imperial, Riverside, Kern, San Benito, San Luis Obispo, Santa Barbara and other counties.
What plant family does Eremothera boothii belong to?
Eremothera boothii is in the Onagraceae family, genus Eremothera.
Related species
Other California species in the same genus, family, or bioregion.
- Eremothera boothii subsp. alyssoides — Pine creek evening-primrose
- Eremothera boothii subsp. boothii — Booth's evening-primrose
- Eremothera boothii subsp. condensata
- Eremothera boothii subsp. decorticans — Shredding evening-primrose
- Eremothera boothii subsp. desertorum
- Eremothera boothii subsp. intermedia — Booth's hairy evening-primrose
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.