Park Milk Vetch

Phaca leptalea (A. Gray) Rydb. Bull. Torrey Club 40; 48. 1913.
IPhaca panciflora Nutt.; T. & G. Fl. N. Am. 1: 348. 1838.
Astragalus pauciflorus A. Grav, Proc. Acad. Phila. II. 7: 60. 1863. Not .4. pauciflorus Pall. 1800;
nor A. pauciflorus Hook. 1831. Astragalus leptaleus A. Gray, Proc. Am. Acad. 6: 220. 1864. Tragacantha leptalea Kuntze, Rev. Gen. 946. 1891.
Perennial, with a slender cespitose root stock; stems slender, decumbent or spreading, 1-2 dm. long, sparingly strigose; leaves 4-7 cm. long; lower stipules connate, deltoid, 3 mm. long, the upper lance-subulate; leaflets 15-25, lance-linear to oblong, often acute, 5-12 mm. long; peduncles 2-5 cm. long, slender; racemes 2-5-flowered; calyx more or less black-hairy, the tube
3 mm. long; the lobes subulate, 2 mm. long; corolla white; banner obovate, emarginate, nearly 1 cm. long; wings 8 mm. long, the blade oblong, with an acute basal auricle; keel-petals 6 mm. long, the blade broadly lunate, rounded at the apex, purple-tipped; pod sessile, strigose with black hairs, ellipsoid, 1 cm. long, 5 mm. wide; seeds obliquely round-reniform, 2 mm. long.
Type locality: Valleys of the Rocky Mountains, in South Park, Colorado. Distribution: Mountains of Colorado.