Matted perennial, forming low cushions up to 30 cm across; stems absent or less than 2 cm; herbage strigose with dolabriform hairs; leaves pinnately compound, to 8 cm long, with 5-7 narrow leaflets; flowers pea-like, solitary on each peduncle, nestled among the leaves, dark reddish-purple, about 15 mm long; pods almost round except for a small beak at the apex, about 3 mm in diameter, hairy. Flowers in May.
The allopatric A. siliceus has 1- to 3-flowered racemes and ovoid pods that are slightly laterally compressed.
New Mexico, Colfax, Harding, and Mora counties.
Greenhorn limestone hills and knolls in shortgrass prairie; 1,800-2,000 m (5,900-6,600 ft).
Limestone knoll habitats are occasionally mined for roadbase materials. Livestock grazing is not a threat to this plant.
Isely, D. 1998. Native and naturalized Leguminosae (Fabaceae) of the United States. Monte L. Beane Life Science Museum, Brigham Young University, Provo, Utah.
Barneby, R.C. 1979. Dragma hippomanicum IV: new taxa of Astragalus sect. Humillimi. Brittonia 31:459-63.
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.