Halfmoon Milkvetch

Phaca allochroa (A. Gray) Rydb. Fl. Rocky Mts. 487, 1063 1917.
Astragalus allochrous A. Gray, Proc. Am. Acad. 13: 366. 1878.
Perennial, with a caudex; stems eitct, 3-5 dm. high, sparingly strigose; leaves strongly ascending, about 1 dm. long; stipules deltoid, acuminate, pubescent, scarious, 4-5 mm. long; rachis strigose; leaflets 11-19, oblong to obovate, rounded to retuse at the apex, strigose on both sides; peduncles 5-7 cm. long; racemes 310 cm. long, 8-15-flowered; bracts lance-subulate, 2-3 mm. long; calyx strigose, the tube campanulate, 3 mm. long, the teeth subulate, 1.5 mm. long; wings shorter than the banner, the blade longer than the claw, oblong; keel-petals strongly incurved, the blade obliquely obovate, lounded at the apex; pod sessile, strigulose, about 3 cm. long and 1.5 cm. wide, acute, the upper suture nearly stiaight; seeds obliquely reniform, brown,
2 mm. long.
Type locality: Near Wickenburg, Arizona. Distribution: Arizona and southern New Mexico.