天山棘豆 tian shan ji dou

Oxytropis brachycarpa Vassilczenko; O. pulvinata Sa­poshnikow.

Herbs, 4-5 cm tall, caulescent, from a multiheaded cau­dex, mat-forming, grayish white pubescent. Stems prostrate and diffuse, ± mat-forming, with 1-4 or more apparent internodes, with appressed dense white trichomes. Stipules ovate-lanceo­late, 3-5 mm, herbaceous, densely white pilose, adnate to peti­ole for most of length, basally connate. Leaves (0.5-)1-3 cm, 9-15-foliolate; petiole and rachis with spreading white tri­chomes; leaflets densely arranged; leaflet blades broadly elliptic to lanceolate, (1-)2-5 × 1-3 mm, both surfaces with dense white trichomes, margin ciliate. Racemes compact, 5-10-flow­ered; peduncle 1.5-3.5 cm, as long as or longer than leaves, with white trichomes; bracts lanceolate, 3-5 mm, longer than pedicels, with white trichomes. Calyx cylindric, (5.5-)6-10 mm, densely villous with spreading long trichomes and black short trichomes; lobes subulate, as long as or sometimes slightly longer than tube. Corolla purple; standard 0.8-1.2 cm, lamina orbicular, apex ± emarginate; wings oblong, 8-9 mm; keel 6-7 mm, beak (0.5-)1-1.5 mm. Legume stipitate; stipe 1-2 mm; body broadly ellipsoid-oblong, 10-15 × 3-5 mm, thickly mem­branous, 2-locular, with white and black trichomes intermixed, septum ca. 0.3 mm wide, adaxial suture deeply grooved. Fl. Jun-Aug, fr. Jul-Aug. 2n = 16.

Floodplain grasslands, saline grassy areas, sandy areas by rivers, rocky alpine areas; 3000-4400 m. Xinjiang, Xizang [Kyrgyzstan, Tajikistan].