Thermopsis gracilis
Slender goldenbanner
(c) Ed Alverson, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Thermopsis gracilis (Slender goldenbanner) is a native California herb in the Fabaceae family, recognized by green color, fewer flowers per node, and longer pedicels.
Slender goldenbanner is a California native perennial herb found in the Klamath Ranges and northern Coast Ranges in open sites and mixed-evergreen forests at elevations of 100 to 1,200 meters. Flowering from April to June, this plant produces yellow flowers in loose clusters along stems 30 to 80 centimeters tall. Growing with green stems that have irregular branching, it forms an upright clump with distinctive compound leaves. Its leaves feature three to seven leaflets that are glabrous to sparsely soft-hairy, with 12 to 18 lateral veins giving them a delicate, intricate texture. The plant produces straight fruits that spread outward, adding to its distinctive architectural presence in the forest understory.
Identification and appearance
Key characters: 3 sympatric species; distinguished by green color, fewer flowers per node, and longer pedicels
Habitat and range
Habitat: Open sites, generally mixed-evergreen forest
Elevation: 100-1200 m
California counties: Shasta, Lake, Del Norte, Trinity, Monterey, Humboldt, Siskiyou, San Diego, Modoc, Napa
Outside California: western Oregon
Bloom period
Thermopsis gracilis blooms Apr-Jun.
Conservation status
CNPS 4.3
How to tell it apart
vs Lupinus: Thermopsis has all stamens free and separate; Lupinus has stamens fused into a tube.; vs Genista: Thermopsis has compound palmate leaves; Genista has simple undivided leaves or is nearly leafless.; vs Lotus: Thermopsis grows in mountains with large yellow flowers; Lotus is lowland with tiny yellow flowers.; vs Cleomella: Thermopsis has pea flowers; Cleomella has four-petaled flowers with long stamens.; vs Acmispon: Thermopsis has large yellow flowers (15-25 mm); Acmispon has tiny yellow flowers under 10 mm.
Frequently asked questions
Is Thermopsis gracilis native to California?
Yes. Thermopsis gracilis is native to California (recorded as native).
When does Thermopsis gracilis bloom?
Thermopsis gracilis blooms Apr-Jun.
Where in California does Thermopsis gracilis grow?
Thermopsis gracilis occurs in Shasta, Lake, Del Norte, Trinity, Monterey, Humboldt, Siskiyou, San Diego and other counties, at elevations of 100-1200 m.
What plant family does Thermopsis gracilis belong to?
Thermopsis gracilis is in the Fabaceae family, genus Thermopsis.
Is Thermopsis gracilis rare or endangered?
Thermopsis gracilis carries California Rare Plant Rank 4.3, state rank S4.
Related species
Other California species in the same genus, family, or bioregion.
- Thermopsis macrophylla — Santa ynez false-lupine
- Thermopsis robusta — Robust false-lupine
- Thermopsis sp. — Golden pea
- Thermopsis californica — California goldenbanner
- Thermopsis californica var. argentata — Silvery false-lupine
- Thermopsis californica var. californica — California goldenbanner
- Trifolium albopurpureum — Indian clover
Sources: Jepson eFlora · CNPS Rare Plant Inventory · 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.