Description from Flora of China
Thermopsis atrata Czefranova.
Perennial herbs, 8-30 cm tall, densely white or brown villous, with silky sheen, sparsely so in fruit. Stems erect, branched, ridged; leaves at base 4-7 verticillate and connate into a sheath. Stipules leafy; leaflets oblong or lanceolate to oblanceolate, 1-2(-3) × 0.3-0.5(-1) cm, lateral leaflets unequal, densely white villous on both surfaces, base tapering to narrowly winged petiole, apex acute. Racemes lax, 4-19 cm; bracts ovate, 1-1.5 cm, base connate into a sheath. Calyx 1.4-2(-2.3) cm. Corolla deep purple, sometimes becoming blue when dry, 2.4-2.8 cm, petals subequal. Ovary 4-13-ovuled, with 4-8 mm stipe, villous. Legume brown, narrowly elliptic, acute, 2-4.5 × 1-1.8 cm. Seed yellowish brown, reniform, 7-8 × 4-5 mm, convex; hilum white. Fl. Jun-Jul, fr. Aug-Sep.
Valleys, slopes; 2700-4500 m. Qinghai, W Sichuan, Xinjiang (Tian Shan), Xizang, SW Yunnan [India, Kashmir, Nepal, Pakistan].