Xylophacos castaneaeformis

Xylophacos castaneaeformis (S. Wats.) Rydb. Bull. Torrey Club 52: 155. 1925.
Astragalus castaneaeformis S. Wats. Proc. Am. Acad. 20: 361. 1885.
Astragalus argophyllus castaneaeformis M. E. Jones, Contr. W. Bot. 10: 62. 1902.
A perennial, with a deep root and cespitose caudex; stems very short, less than 5 cm. long, leafy, mostly covered by the stipules; leaves 5-8 cm. long, ascending; stipules deltoid, 3-5 mm. long; leaflets 7-17, oval or obovate, rounded at the apex, 5-12 mm. long, 3-8 mm. wide, silky-canescent, strigose on both sides; peduncles 2-5 cm. long, shorter than the leaves; racemes 4— 7-flowered; bracts lanceolate, 3 mm. long; calyx strigose-canescent, the tube about 8 mm. long, the teeth subulate, 2 mm. long; corolla purplish, about 15 mm. long; banner narrowly obovate, slightly retuse ; wings slightly shorter, with oblong blades ; keel-petals much shorter, strongly lunate; pod ovoid, comparatively thin-valved, strigose, about 15 mm. long, abruptly acuminate.
Type locality: William Station. Arizona.
Distribution: Central Arizona.