With branching, reddish stems to 12-inches long, this small milkvetch grows prostrate and spreading to bushy. The pinnately compound leaflets are slightly hairy and tend to fold along the midrib. Note the few-flowered clusters of small, magenta to dark-purple flowers, and the oval, inflated pods. Small, stiff hairs cover the foliage. Addictive alkaloids in the foliage cause deadly “locoweed poisoning” in livestock.

FLOWER: March–May. Loose clusters are held within the leaves and have 4–12 small, pinkish to purple, pea-like flowers; each flower is 1/4–3/8 inch long (6–9 mm) with 5 petals: 1 oval upper banner with white streaks, 2 side wings, and 2 central keel petals that arch upward. Fruits are an oval, inflated, thin-walled pod, green to reddish-tinged, 5/8–1 inch long (12–25 mm). Var. allochrous has asymmetrical pods; var. playanus has symmetrical oval pods.

LEAVES: Alternate. Blades compound with 11–19 linear-oblong to elliptic leaflets, each 5/16–1 inch long (8–25 mm); surfaces sparsely covered with small, stiff hairs, edges folded lengthwise.

HABITAT: Sandy, gravelly, loam soils; slopes washes, flats, foothills, brushlands, grasslands; sagebrush-rabbitbrush flats, pinyon-juniper woodlands, mixed conifer forests.

ELEVATION: 4,000-8,600 feet.

RANGE: AZ, CA, CO, NM, TX.

SIMILAR SPECIES: The branching, reddish stems, foliage with short, stiff hairs, small flowers, and inflated pods help distinguish this species. Flora Neoxexicana III (Allred, 2012) recognizes two varieties, var. allochrous and var. playanus, and says, “We have two intergrading varieties scattered nearly throughout NM.” Other authorities classify Astragalus allochrous var. playanus as a separate species, Astragalus wootonii. Plants with intermediate characteristics are reported from Mesilla Valley (Dona Ana County.)

NM COUNTIES: Scattered in the western 2/3 of NM in low- to mid- elevation, dry habitats:  Bernalillo, Catron, Cibola, Dona Ana, Grant, Hidalgo, Lincoln, Los Alamos, Luna, McKinley, Otero, Rio Arriba, San Juan, Sandoval, Santa Fe, Sierra, Socorro, Taos, Torrance, Valencia.