Linum trigynum
French flax
(c) Thomas Mesaglio, some rights reserved (CC BY), uploaded by Thomas Mesaglio · licence
Family: Linaceae · Type: Herb · Not Native
Linum trigynum (French flax) is a non-native California herb in the Linaceae family, recognized by small yellow flowers with fused petals.
French flax is a naturalized annual found in northern coastal California, specifically Sonoma County, in grasslands and disturbed areas at elevations below 500 meters. Flowering from May to June, this plant produces bright yellow flowers with petals 3.5 to 6 millimeters long. Growing with slender stems 10 to 35 centimeters tall that are completely smooth and hairless, it has delicate linear to lance-shaped leaves 5 to 20 millimeters in length. Its narrow leaves are accompanied by small yellow flowers with petals fused at the base, creating a distinctive appearance in open grassland settings. The fruit splits into 10 slightly adherent segments, containing small yellowish-brown seeds about 1 to 2 millimeters long.
Identification and appearance
Key characters: 4 sympatric species; small yellow flowers with fused petals are diagnostic
Habitat and range
Habitat: Grassland, disturbed areas
Elevation: < 500 m
Outside California: native to Mediterranean Eurasia, north Africa, naturalized in Hawaii, Australia, New Zealand
Bloom period
Linum trigynum blooms May-Jun.
How to tell it apart
vs Nemophila: Linum has 5 separate styles; Nemophila has 1-2 styles.; vs Leptosiphon: Linum has 5 styles and no petal tube; Leptosiphon has 3 styles and fused petals forming a tube.; vs Pelargonium: Linum has 5 equal styles and radial flowers; Pelargonium has fused styles and bilateral flowers.; vs Papaver: Linum has 5 distinct styles; Papaver has a disc-like stigma with no separate styles.; vs Gilia: Linum has 5 separate styles; Gilia has 3 styles and tubular fused petals.
Frequently asked questions
Is Linum trigynum native to California?
No. Linum trigynum is not native to California (recorded as not native).
When does Linum trigynum bloom?
Linum trigynum blooms May-Jun.
What plant family does Linum trigynum belong to?
Linum trigynum is in the Linaceae family, genus Linum.
What habitat does Linum trigynum grow in?
Linum trigynum grows in Grassland, disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.