With a dense basal rosette with pinnately compound leaves and flower stalks with 6–12 inch tall spikes of white pea-like flowers, this robust locoweed contains neurological toxins that addict and poison livestock. Note the white flowers, basal leaves with silky-hairy foliage, and bean-like seed pods. Addictive alkaloids in the foliage cause deadly “locoweed poisoning” in livestock.

FLOWER: May–September. Flower stalk (scape) to 20 inches tall (50 cm); the spike-like cluster (raceme) has 6–15 flowers each 5/8–1 inch long (15–25 mm), that spread upward (not drooping) on the stem; petals white, sometimes with purple spots or streaks. Fruit is an erect, oblong bean pod 5/8–1 inch long (15–25 mm), covered with silky hairs and tipped with a short beak.

LEAVES: Basal. Blades 2–8 inches long (5–20 cm) with 9–23 narrowly-oval leaflets mostly opposite along midrib; each leaflet 3/8–1 5/8 inches long (1–4 cm); surfaces covered with flat-lying, silky hairs.

HABITAT: Dry sandy, gravelly soils of canyons, mesas, dry washes, plains, foothills, meadows, forest openings; sage brushlands, pinyon-juniper woodlands, pine-Douglas fir forests.

ELEVATION: 6,000–9,200 feet.

RANGE: CO, ID, KA, MT, NE, NM, NV, OK, UT, SD, TX, WY.

SIMILAR SPECIES: Purple Locoweed, O. lambertii, in much  the same range and habitat, has similar foliage but purple flowers. The white flowers, basal rosette of silky-hairy leaves, and hairy pods with beaks separate this species from similar locoweeds in the Astragalus genus.

NM COUNTIES: Nearly statewide, except southern desert and eastern plains counties, in mid elevation, dry habitats: Bernalillo, Catron, Chaves, Cibola, Colfax, Grant, Harding, Lincoln, Los Alamos, McKinley, Mora, Otero, Quay, Rio Arriba, San Juan,, San Miguel, Sandoval, Santa Fe, Sierra, Socorro, Taos, Torrance, Union, Valencia.