线棘豆 xian ji dou

Oxytropis coerulea Turczaninow (1842), not O. caerulea (Pallas) Candolle (1802).

Herbs, 10-20 cm tall, acaulescent, from a multiheaded caudex, tufted. Stipules narrowly ovate, membranous, densely appressed sericeous, adnate to petiole, basally connate to almost distinct. Leaves 1.5-12 cm, (5-)17-31(-45)-foliolate; petiole and rachis with appressed white trichomes; petiole long and thin, persistent; leaflet blades lanceolate, linear-lanceolate, or ovate-lanceolate, 2-6 × 0.5-2 mm, with appressed trichomes, base rounded, margin involute, apex acuminate. Racemes lax, 2.5-5 cm, 10-15-flowered; peduncle 6-11 cm, 1-2 × as long as leaves, thin, usually incurved, with appressed white and black trichomes; bracts linear, longer than pedicels. Calyx broadly campanulate, 2.5-3(-4.9) mm; lobes triangular, 0.4-0.6(-1.3) mm, with dense white and black short trichomes. Corolla bluish purple; standard 5.5-7 mm, lamina suborbicular, apex emargi­nate; wings 5-6 mm, as long as standard, slightly longer than keel, lamina oblong; keel 4.5-6 mm, beak ca. 1.5 mm. Legume subsessile; body broadly ellipsoid to ovoid, 5-10 × 3-5 mm, thickly membranous, 1-locular, with appressed sparse white and black short trichomes, apex beaked. Fl. Jul-Aug, fr. Aug. 2n = 16, 32.

Roadsides on gravelly or stony mountain slopes, meadows; 600-700 m. Nei Mongol [Mongolia, Russia].