Astragalus esperanzae M. E. Jones

Hamosa esperanzae (M. E. Jones) Rydb. Bull. Torrey Club 54:335. 1927.
Astragalus Esperanzae M. E. Jones, Rev. Astrag. 277. 1923. Astragalus chapalanus M. E. Jones, Rev. Astrag. 277. 1923.
A peiennial, with cespitose root-stock; stems several, decumbent, 1-2 dm. high, terete, strigose, branched; leaves spreading, 3-6 cm. long, the rachis strigose; stipules lanceolate to ovate, 3-4 mm. long; leaflets 15-25, oblong or oblanceolate, 5-12 mm. long, 1-2 mm. wide, acute at the base, obtuse, truncate, or retuse at the apex, glabrous above, strigose beneath; peduncles 3-7 cm. long, strict; racemes short and dense, 2-3 cm. long; bracts lanceolate, membranous, 2-3 mm. long; pedicels about 1 mm. long; calyx black-hairy, the tube 2.5 mm. long, the teeth lanceolate, 2 mm. long; corolla white or greenish-white, tinged with purple; banner 7-8 mm. long, obovate, strongly arched ; wings nearly as long, the blade broadly obliquely obovate, with a large rounded auricle; keel-petals shorter, the blade broadly lunate, almost semiorbicular, rounded and purple at the tip; pod glabrous, lanceolate in outline, falcate, 12-16 mm. long, 3 mm. wide and thick, cordate in cross-section.
Type locality: Esperanza, Puebla.
Distribution: San Luis Potosi to Jalisco and Hidalgo.