Hosackia oblongifolia var. cuprea
Copper-flowered bird's-foot trefoil
(c) Tom Hilton, some rights reserved (CC BY), uploaded by Tom Hilton · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.3
Hosackia oblongifolia var. cuprea (Copper-flowered bird's-foot trefoil) is a native California herb in the Fabaceae family, recognized by high elevation and small flower size diagnostic.
Copper-flowered bird's-foot trefoil is a rare (CNPS 1B.3) California native perennial found in northern Sierra Nevada Foothills in Calaveras County, southern Sierra Nevada in Tulare County, and Sierra Nevada East in meadows and open pine woodlands at elevations of 2,400 to 2,800 meters. Flowering from July to August, this plant produces copper-colored flowers in small clusters approximately 8 to 9 millimeters long. Growing with slender stems 15 to 30 centimeters tall, it forms compact clumps in alpine and subalpine environments. Its leaves are distinctive, composed of 3 to 7 smooth, glabrous leaflets arranged in a trefoil pattern. The compact growth and copper-toned flowers make this trefoil a subtle but charming alpine wildflower.
Identification and appearance
Key characters: 5 sympatric species; high elevation and small flower size diagnostic
Habitat and range
Habitat: Meadows, open pine woodland
Elevation: 2400-2800 m
Bloom period
Hosackia oblongifolia var. cuprea blooms Jul-Aug.
Conservation status
CNPS 1B.3
How to tell it apart
vs Acmispon: Hosackia has conspicuous papery or leafy stipules; Acmispon stipules tiny or absent.; vs Lathyrus: Hosackia has umbrella clusters; Lathyrus flowers on stalks with leaves having tendrils.; vs Lotus: Hosackia is native perennial in natural habitats; Lotus is introduced in disturbed sites.; vs Vicia: Hosackia flowers in umbels; Vicia flowers in rows with leaves ending in tendrils.; vs Securigera: Hosackia pods split open straight; Securigera pods break into curved segments.
Frequently asked questions
Is Hosackia oblongifolia var. cuprea native to California?
Yes. Hosackia oblongifolia var. cuprea is native to California (recorded as native).
When does Hosackia oblongifolia var. cuprea bloom?
Hosackia oblongifolia var. cuprea blooms Jul-Aug.
What plant family does Hosackia oblongifolia var. cuprea belong to?
Hosackia oblongifolia var. cuprea is in the Fabaceae family, genus Hosackia.
Is Hosackia oblongifolia var. cuprea rare or endangered?
Hosackia oblongifolia var. cuprea carries California Rare Plant Rank 1B.3, state rank S2.
What habitat does Hosackia oblongifolia var. cuprea grow in?
Hosackia oblongifolia var. cuprea grows in Meadows, open pine woodland.
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.