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Astragalus wittmannii
(One-flowered milkvetch)
[taxon report][distribution map][photos][line drawing]
Family: Fabaceae
Scientific Name: Astragalus wittmannii Barneby
Synonyms: None
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):
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.
Isely, D. 1998. Native and naturalized Leguminosae (Fabaceae) of the United States. Monte L. Beane Life Science Museum, Brigham Young University, Provo, Utah.
Information Compiled By: Ken Heil, Joey Herring, 1999
Agency Status:
