Thermopsis macrophylla
Santa ynez false-lupine, Santa Ynez False-Lupine
(c) Matt Berger, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.3
Thermopsis macrophylla (Santa ynez false-lupine) is a native California herb in the Fabaceae family, recognized by exceptional size and long inflorescences.
Santa ynez false-lupine is a rare (CNPS 1B.3) California native perennial found in the Santa Ynez Mountains in sandstone chaparral at elevations of 1,000 to 1,400 meters. Flowering from May to June, this plant produces yellow flowers in elongated clusters with 3 to 5 blossoms per node. Growing 1.2 to 2.5 meters tall with erect, stout stems that branch at the base and are covered in gray hairs, it has a robust and distinctive appearance. Its compound leaves feature leaflets 4 to 10 centimeters long, densely covered in long, soft, wavy hairs with 12 to 16 lateral veins, giving the plant a distinctly textured look. The fruit is straight, ascending, and densely hairy, completing the plant's characteristically soft and gray-green profile.
Identification and appearance
Key characters: 2 sympatric species; distinguished by exceptional size and long inflorescences
Habitat and range
Habitat: Sandstone, chaparral
Elevation: 1000-1400 m
California counties: Santa Barbara, San Luis Obispo, Los Angeles, San Diego, Humboldt, Sonoma, Napa, Monterey, Lake, Santa Cruz, Marin, Ventura, Siskiyou, Del Norte, Mendocino, Santa Clara
Bloom period
Thermopsis macrophylla blooms May-Jun.
Conservation status
CNPS 1B.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 macrophylla native to California?
Yes. Thermopsis macrophylla is native to California (recorded as native).
When does Thermopsis macrophylla bloom?
Thermopsis macrophylla blooms May-Jun.
Where in California does Thermopsis macrophylla grow?
Thermopsis macrophylla occurs in Santa Barbara, San Luis Obispo, Los Angeles, San Diego, Humboldt, Sonoma, Napa, Monterey and other counties, at elevations of 1000-1400 m.
What plant family does Thermopsis macrophylla belong to?
Thermopsis macrophylla is in the Fabaceae family, genus Thermopsis.
Is Thermopsis macrophylla rare or endangered?
Thermopsis macrophylla carries California Rare Plant Rank 1B.3, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
- 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
- Thermopsis californica var. semota — Velvety false-lupine
- Trifolium albopurpureum — Indian clover
- Trifolium alexandrinum — Egyptian clover
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.