Mentzelia oreophila
Argus blazing star
(c) Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger · licence
Family: Loasaceae · Type: Subshrub · Native
Mentzelia oreophila (Argus blazing star) is a native California subshrub in the Loasaceae family, recognized by distinctive perennial habit with winged seeds and spiral-twisted anthers.
Argus blazing star is a California native perennial found in the White and Inyo Mountains, eastern Desert Mountains, and eastern Desert Sonoran regions in rocky washes, roadcuts, and talus slopes at elevations of 150 to 2,200 meters. Flowering from February to October, this plant produces bright yellow flowers 7 to 17 millimeters long with obtuse to rounded tips. Growing with erect, hairy stems 15 to 53 centimeters tall that branch throughout, it develops from a branched tap-rooted caudex. Its leaves vary distinctively, with lower leaves 2 to 10 centimeters long, 6 to 40 millimeters wide, oblanceolate to elliptic and slightly wavy-toothed, while upper leaves are shorter and deltate to heart-shaped with clasping bases. The fruit is an erect, cup-shaped structure 5 to 10 millimeters long, containing small white to pale gray seeds with white wings.
Identification and appearance
Key characters: 18 sympatric species; distinctive perennial habit with winged seeds and spiral-twisted anthers
Habitat and range
Habitat: Washes, roadcuts, talus slopes of limestone soils
Elevation: 150-2200 m
California counties: Inyo, San Bernardino, Mono
Outside California: southern Nevada
Bloom period
Mentzelia oreophila blooms Feb-Oct.
How to tell it apart
vs Camissoniopsis: Mentzelia has many stamens and 3 stigmas; Camissoniopsis has 8 stamens and 4 stigmas.; vs Leptosiphon: Mentzelia has free petals and many stamens; Leptosiphon has fused petals forming a tube.; vs Emmenanthe: Mentzelia has free petals and 3 stigmas; Emmenanthe has fused bell-shaped petals.; vs Eschscholzia: Mentzelia has many stamens and 3 stigmas; Eschscholzia has many stamens and 4 stigmas.; vs Potentilla: Mentzelia has 3 stigmas and capsule fruit; Potentilla has many pistils and achene fruits.
Frequently asked questions
Is Mentzelia oreophila native to California?
Yes. Mentzelia oreophila is native to California (recorded as native).
When does Mentzelia oreophila bloom?
Mentzelia oreophila blooms Feb-Oct.
Where in California does Mentzelia oreophila grow?
Mentzelia oreophila occurs in Inyo, San Bernardino, Mono, at elevations of 150-2200 m.
What plant family does Mentzelia oreophila belong to?
Mentzelia oreophila is in the Loasaceae family, genus Mentzelia.
What habitat does Mentzelia oreophila grow in?
Mentzelia oreophila grows in Washes, roadcuts, talus slopes of limestone soils.
Related species
Other California species in the same genus, family, or bioregion.
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.