Hesperolinon breweri
Brewer's western flax, Brewer's Western Flax
(c) Ken-ichi Ueda, some rights reserved (CC BY) · licence
Family: Linaceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Hesperolinon breweri (Brewer's western flax) is a native California herb in the Linaceae family, recognized by dense inflorescence and large petals.
Brewer's western flax is a rare (CNPS 1B.2) California native annual found in southern North Coast Ranges, northwestern San Joaquin Valley, and northeastern San Francisco Bay region, including Napa, Solano, Contra Costa counties and Mount Diablo area in chaparral and grassland habitats at elevations of 30 to 700 meters. Flowering from May to June, this delicate plant produces small yellow flowers 4 to 10 millimeters long with distinctive gland-toothed sepals. Growing 5 to 20 centimeters tall with an almost glabrous (nearly hairless) appearance, it has a slender and compact form. Its leaves are alternate and linear, creating a fine, sparse foliage structure. The plant features three distinct yellow styles and yellow anthers, giving it a subtle but charming appearance in its native grassland habitats.
Identification and appearance
Key characters: 5 sympatric species; distinguished by dense inflorescence and large petals
Habitat and range
Habitat: Chaparral or grassland, occasionally on serpentine
Elevation: 30-700 m
California counties: Contra Costa, Napa, Solano, Alameda
Bloom period
Hesperolinon breweri blooms May-Jun.
Conservation status
CNPS 1B.2
How to tell it apart
vs Linum: Hesperolinon has 2-3 styles and whorled basal leaves; Linum has 5 styles and alternate leaves.; vs Gayophytum: Hesperolinon has whorled leaves and 2-3 styles; Gayophytum has alternate leaves and 4-parted flowers.; vs Eremogone: Hesperolinon has 2-3 styles; Eremogone has 3 styles and opposite leaves throughout.; vs Nemacladus: Hesperolinon has regular radial flowers; Nemacladus has strongly bilateral flowers.; vs Sclerolinon: Hesperolinon has 3 styles and stipule glands present; Sclerolinon has 2 club-shaped styles and no glands.
Frequently asked questions
Is Hesperolinon breweri native to California?
Yes. Hesperolinon breweri is native to California (recorded as native).
When does Hesperolinon breweri bloom?
Hesperolinon breweri blooms May-Jun.
Where in California does Hesperolinon breweri grow?
Hesperolinon breweri occurs in Contra Costa, Napa, Solano, Alameda, at elevations of 30-700 m.
What plant family does Hesperolinon breweri belong to?
Hesperolinon breweri is in the Linaceae family, genus Hesperolinon.
Is Hesperolinon breweri rare or endangered?
Hesperolinon breweri carries California Rare Plant Rank 1B.2, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.