96. Oxytropis merkensis Bunge, Bull. Soc. Imp. Naturalistes Moscou. 39(2): 65. 1866.
米尔克棘豆 mi er ke ji dou
Astragalus loczyi Kanitz var. scaposa Kanitz; ?Oxytropis avis Saposhnikow; O. kanitzii N. D. Simpson.
Herbs, to 30 cm tall or more, acaulescent, from a multiheaded caudex, clothed with marcescent leaf bases and stipules, grayish pubescent. Stipules with a lanceolate-subulate free part, sparsely to densely appressed pubescent, adnate to petiole, base triangular, margin ciliate. Leaves 5-15 cm, 13-25-foliolate; leaflet blades oblong, broadly elliptic-lanceolate, or lanceolate, 5-20 × 2-5 mm, both surfaces sparsely pubescent, margin slightly involute, apex acute. Racemes lax, many flowered, elongating to 10-20 cm after anthesis; peduncle 15-25 cm, 1-2(-3) × as long as leaves, with appressed sparse white trichomes; bracts subulate, with sparse trichomes. Calyx campanulate, 3.6-5 mm, with appressed black trichomes; lobes subulate, ca. 1.3 mm, shorter than tube. Corolla purple to almost white; standard 7-10 mm, lamina suborbicular, apex emarginate; wings as long as or slightly shorter than standard; keel ca. 8.8 mm, as long as or longer than wings, tip spotted, beak 0.5-1.8 mm. Legume stipitate; stipe 4-5 mm; body broadly ellipsoid-oblong, 10-16 × 5-6 mm, pendulous, papery, with appressed white trichomes, apex acuminate. Fl. Jun-Jul, fr. Jul-Aug. 2n = 16, 32.
Grasslands on hillsides, river terraces and floodplains, gravelly areas, roadsides, fields, dry slopes, flooded lands, subalpine meadows; 1700-4600 m. Gansu, Nei Mongol, Ningxia, Qinghai, Xinjiang, Xizang [Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan].
According to the description of Oxytropis avis in Fl. URSS (13: 26. 1948), the keel beak is 0.5-0.75 mm, the leaflets are 4-6-paired, the peduncle is to 15 cm and several × longer than the leaves, and the racemes are loose and few flowered. Whether it is really conspecific with O. merkensis requires additional investigation.