Astragalus hypoleucus Schau.

Hamosa hypoleuca (Schauer) Rydb. Bull. Torrey Club 54: 334. 1927.
Astragalus hypoleucus Schauer. Linnaea 20: 747. 1847. Tragacantha hypoleuca Kuntze, Rev. Gen. 945. 1891. Astragalus luisanus M. E. Jones, Rev. Astrag. 275. 1923.
A cespitose perennial; stems several from a woody root and caudex, 1-1.5, rarely 2 dm. high, silvery-canescent ; leaves 4-7 cm. long, ascending, the rachis silvery; stipules lancedeltoid, 3 mm. long; leaflets 15-21, oblong or oblanceolate, acutish at each end, 5-12 mm. long, 1-2 mm. wide, silvery-canescent; peduncles 5-8 cm. long; racemes elongate, 3-5 cm. long, many-flowered; bracts lance-subulate, membranous, 2-3 mm. long; pedicels 0.5 mm. long; calyx more or less black-hairy, the tube 2.5 mm. long, the teeth subulate, 1 mm. long; corolla ochroleucous; banner obovate, moderately arched; wings nearly as long, the blade obovate; keel-petals much shorter, the blade semi-orbicular, purple-tipped; pod oblong-lanceolate in outline, falcate, about 1 cm. long, 3 mm. wide and thick, obtuse at the base, tapering at the apex, canescent with kinky hairs, the cross-section broadly cordate.
Type locality: Mexico, the exact locality not indicated.
Distribution: Coahuila to Hidalgo and Puebla.