With dense clusters of reddish to green stems reaching 3-feet tall and numerous spikes with drooping pale-yellow flowers, this widespread milkvetch has a fetid odor, as the common name implies. Note the foliage is hairless throughout. Selenium concentrated in the foliage is toxic to livestock.

FLOWERS: April–August. Spike-like flower stalks have 10–33 pale yellow to white flowers 5/8–1-inch long (15–24 mm) with 5 petals; 1 upward slanting banner, 2 side wing petals, 2 fused keel petals shorter than the wings and often with a dark tip. Fruit a tubular, inflated pod 3/4–1 5/8-inches long (18–42 mm), 3/16–1-inch (5–25 mm) wide.

LEAVES: Alternate, pinnately compound. Blades 1 3/16–8 3/4-inches (3–22 cm) long; 7–33 leaflets oval to lance-shaped, 1/8–2-inches (3–50 mm) long with rounded bottom, pointed tip, hairless on top, few hairs on bottom.

HABITAT: Selenium rich clay, sandy, silty soils, roadsides, disturbed areas; desert shrub, pinyon-juniper woodlands.

ELEVATION: 3,900–7,200 feet.

RANGE: AZ, CO, NM, NV, UT, TX.

SIMILAR SPECIES: 2 varieties in NM with slight pod differences: var. praelongus mostly eastern half NM; var. ellisiae mostly western 1/2 NM. Giant Milkvetch, A. giganteus, rare in so. NM mountains, has yellow flowers but is densely hairy throughout.

NM COUNTIES: Nearly statewide in low- to mid elevation, dry habitats in selenium soils: Bernalillo, Catron, Chaves, Cibola, Colfax, Dona Ana, Grant, Guadalupe,  Los Alamos, McKinley, Otero, Quay, Rio Arriba, Roosevelt, San Juan, San Miguel, Santa Fe, Sandoval, Sierra, Socorro, Torrance, Union, Valencia..