Herbs robust, (2.5–)3–8(–9) dm, sericeous, villous, or tomentose. Stems slender, erect, clustered, many-branched, from rhizomes; branches ascending at 20–45º, weakly to strongly zigzag. Leaves: stipules persistent, widely ovate to lanceolate, 1.5–6.5 × 0.7–5 cm, base cuneate to cordate or amplexicaul, apex acuminate; petiole 1–3.5 cm; leaflet blades elliptic, obovate, or rhombic, 3–7(–9) × 1.2–4(–4.5) cm, lateral veins 6–9 pairs, conspicuously net-veined abaxially, apex obtuse to acute, surfaces silvery-sericeous or tomentose to villous. Peduncles 2–10 cm; bracts semipersistent, ovate to lan­ceolate, 6–15(–30) × 2.5–15(–20) mm. Racemes 10–40-flowered, 7–30(–35) cm; flowers mostly in whorls of 3–5. Pedicels 2–6 mm, sericeous or tomentose. Flowers 1.5–2 cm; calyx 5–9(–10) × 5–9 mm at limb, lobes 2.5–5 mm, equal to or longer than tube; wing and keel petals asymmetrically oblong-elliptic or, sometimes, reniform (var. argentata); ovary velutinous; ovules 5–11. Legumes ascending (irregularly divaricate when young), straight, 2–6(–7) × (0.5–)0.6–0.9 cm, sericeous, tomentose, or velutinous. Seeds 1–6(–10), brown, oblong, 4–5(–5.5) × (2.5–)2.8–4 mm, short-beaked.

Distribution

California.

Discussion

Varieties 3 (3 in the flora).

Selected References

None.

Lower Taxa

Thermopsis californica var. argentata, Thermopsis californica var. californica, Thermopsis californica var. semota

Key

1	Stipules widely to narrowly ovate, 1.5–5 cm wide; floral bracts 3–15 (–20) mm wide; peduncles (4–)6–10 cm.	Thermopsis californica var. californica
1	Stipules ovate to lanceolate, 0.7–2.5 cm wide; floral bracts 2.5–6 mm wide; peduncles 2–7(–10) cm.	> 2
2	Herbs silvery-sericeous; wing and keel petals oblong-elliptic to reniform; Kern, Lassen, Los Angeles, Modoc, Santa Barbara, Shasta, Siskiyou, Ventura counties.	Thermopsis californica var. argentata
2	Herbs densely silvery-tomentose; wing and keel petals oblong-elliptic; San Diego County.	Thermopsis californica var. semota