阴山棘豆 yin shan ji dou

Herbs, (3.5-)5-8 cm tall, acaulescent, from a multiheaded caudex, clothed with marcescent leaf bases and stipules. Stip­ules lanceolate, with dense long trichomes, basally adnate to petiole. Leaves (2-)5-8 cm, 5-9-foliolate; leaflet blades linear, (0.6-)1-1.3(-1.4) cm × 0.5-1.5 mm, both surfaces glabrous, base cuneate, margin ciliate, apex attenuate. Racemes 2-5-flow­ered; peduncle shorter than to as long as leaves, with long tri­chomes; bracts ovate-elliptic, ca. 10 × 5-7 mm, both surfaces glabrous, margin ciliate, apex acute. Calyx cylindric, 1-1.5 cm, with dense white and black long trichomes; lobes linear-lan­ceolate, 2.5-4 mm. Corolla purple to bluish purple; standard 2-3 cm, lamina subelliptic, apex rounded or subtruncate; wings 1.8-2 cm, lamina obliquely obovate, apex rounded; keel ca. 1.8 cm, subequal to wings, beak 1-1.8 mm. Legume sessile, ovoid, 1-1.5 × ca. 0.8 cm, inflated, membranous, with spreading dense long trichomes. Fl. May-Jul, fr. Jul-Aug.

● Dry slopes, gravelly areas in valleys; 1800-2100 m. Nei Mon­gol.