Orophaca sericea (Torr. & A. Gray) Britton

Orophaca sericea (Nutt.). Britton; Britt. & Brown, 111. Fl 2:307. 1897.
Phaca sericea Nutt.; T. & G. Fl. N. Am. 1: 343. 1838. Astragalus sericoleucus A. Gray, Am. Jour. Sci. II. 33: 410. 1862. Tragacantha sericea Kuntze, Rev. Gen. 942. 1891.
A broadly cespitose plant, with a woody caudex; branches 5-20 cm. long, decumbent, much branched, densely covered with stipules and remains of leaves; leaves crowded, 1-2 cm. long, spreading; stipules pubescent, searious, broadly ovate or suborbicular, 5-8 mm. long; leaflets 3, rarely 5, oblanceolate to cuneate, 5-10 mm. long, silvery-silky on both sides; peduncles about 1 cm. long, arcuate; racemes 1-4-flowered; bracts 1 cm. long, lanceolate; calyx campanulate, silky-canescent, the tube campanulate, 2 mm. long, the teeth subulate, 2 mm. long; corolla purple, in drying turning yellowish, 6-7 mm. long; banner broadly obovate, notched, abruptly arched at the middle; wings slightly shorter, the blade obliquely obovate, with an acute basal auricle and a slender claw; keel-petals much shorter, the blade broadly lunate, rounded at the apex; pod ovoid, scarcely exceeding the calyx, turgid, 4—5 mm. long, sericeous.
Type locality: High hills of the Platte, near the Rocky Mountains [probably Wyoming|. Distribution: Plains, western Nebraska. Wyoming, and northeastern Colorado.

Orophaca sericea là một loài thực vật có hoa trong họ Đậu. Loài này được (Torr. & A.Gray) Britton mô tả khoa học đầu tiên.