[taxon report][distribution map][all photos][line drawing]
Scientific Name: Astragalus wittmannii Barneby
Vernacular Name: One-flowered milkvetch
R-E-D Code: 1-1-3
Description: 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.
Similar Species: The allopatric A. siliceus has 1- to 3-flowered racemes and ovoid pods that are slightly laterally compressed.
Distribution: New Mexico, Colfax, Harding, and Mora counties.
Habitat: Greenhorn limestone hills and knolls in shortgrass prairie; 1,800-2,000 m (5,900-6,600 ft).
Remarks: Endemic to northeastern New Mexico. At least 20 locations have been recorded for this species.
Conservation Considerations: Limestone knoll habitats are occasionally mined for roadbase materials. Livestock grazing is not a threat to this plant.
Important Literature (*Illustration):
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.
Information Compiled By:
Ken Heil, Joey Herring, 1999