[taxon report][distribution map][all photos][line drawing]
Scientific Name: Astragalus gypsodes Barneby
Vernacular Name: Gypsum milkvetch
R-E-D Code: 2-1-2
Description: Perennial; stems stout, ascending, often purplish tinged; leaves pinnately compound, mostly 15-29 foliate, 4-18 cm long; leaflets 5-20 mm long, elliptic to ovate, flat, pubescent on both surfaces, hairs straight, lying flat against the leaf surface; racemes 10-30 flowered; flowers pea-like, 16-24 mm long; petals pinkish-purple when fresh, drying bluish; pods spreading or ascending, oblong, usually straight and plump, 25-50 mm long, 2-chambered, becoming thick, spongy, and bright red when ripe. Flowers March to May.
Similar Species: This is the only milkvetch with pinkish-purple flowers and large, thick, bright red pods that grows on gypsum soils.
Distribution: New Mexico, Eddy County, Yeso Hills; adjacent Texas.
Habitat: Gypseous soils in Chihuahuan desert scrub; 1,050-1,125 m (3,500-4,000 ft).
Remarks: Endemic to the gypsum flats and low gullied gypseous hills of the Permian-aged Castile Formation. It is locally abundant in some places. This species frequently colonizes areas where soil has been disturbed, such as roadsides. It blooms in early spring with an abundance of purple flowers. The thick, bright-red pods are striking when they mature.
Conservation Considerations: Not significantly threatened by the current land uses within its habitats. County road and state highway projects could remove some plants. Gypsum mining is a minor potential threat, if conducted on a large scale.
Important Literature (*Illustration):
Barneby, R.C. 1956. Pugillus Astragalorum XVII. American Midland Naturalist 55:499-500.
Isely, D. 1998. Native and naturalized Leguminosae (Fabaceae) of the United States. Monte L. Beane Life Science Museum, Brigham Young University, Provo, Utah.
*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