Reddish, sprawling to semi-erect stems spread in an arching clump up to 3-feet wide (1 m) with elongated, dense clusters of purple and white, pea-like flowers, and 5–15 pairs of generally hairless leaflets. Note the usually red-freckled pods which are thin-walled and inflated like a bladder. All features are highly variable with at least 42 varieties throughout the West. Addictive alkaloids in the foliage cause deadly “locoweed poisoning” in livestock.

FLOWERS: March–July. Clusters (racemes) of 5–35 purple, pink, white, or cream flowers grow on leafless stems 3/8–5/8 inch long (1–1.5 cm), about the same length as the leaves. Flowers have 5 petals: 1 upper banner with white base with red lines and edges that fold back, and 2 side wings that reach forward beyond the 2 keel petals in the center. Fruit is an inflated oval pod, 1/2–1 inch long (15–24 mm) with a hooked tip and 2 chambers; color varies from solid pale-green to marked with red freckles; an indented seam runs down the top side.

LEAVES: Alternate, pinnately compound, to 6 inches long (15 cm). Paired leaflets along midrib are oval to elliptic, 1/16–1/2-inch long (2–12 mm); surfaces hairless to sparsely hairy.

HABITAT: Sandy, gravelly, loamy soils, roadsides; desert grasslands and scrub, sagebrush scrub, pinion-juniper woodlands.

ELEVATION: 4,800–7,600 feet.

RANGE: AZ, CA, CO, NM, TX, all states west of Rocky Mts.

SIMILAR SPECIES: A. lentginosus is highly variable with two varieties in NM: var. diphysis is widespread; var. australis occurs Hidalgo, Dona Ana cos. More than 75 Astragalus species in NM with similar pea-like flowers. Both flower and fruit are needed for identification. The inflated, 2-chambered pods with red-freckles help identify this species.

NM COUNTIES: Widespread in NM in low- to mid-elevation, dry habitats: Bernalillo, Catron, Chaves, Cibola, Dona Ana, Eddy, Hidalgo, Lincoln, Los Alamos, Luna, McKinley, Otero, Rio Arriba, San Juan, San Miguel, Sandoval, Santa Fe, Sierra, Socorro, Taos, Torrance, Valencia. [Hidalgo, Dona Ana–var. australis]