SHIVWITZ MILK VETCH } Astragulus ampullarioides
FAMILY: Fabaceae

DESCRIPTION: The stems of Shivwitz milk vetch may grow along the ground or vertically to a height of 20 to 50 centimeters, although flowering stems may grow to one meter. Leaves are pinnately compound with 11 to 23 elliptical leaflets. In spring, each plant produces about 45 small, cream-colored flowers on a single stalk; fruit is a short, broad pod that shelters the developing seeds; the plants die back to their root crown after flowering.

HABITAT: Populations of the Shivwitz milk vetch are found at elevations of 3,018 to 4,367 feet upon sparsely vegetated, isolated patches of purple-hued soft clay soil.

RANGE: All currently known six locations of the Shivwitz milk vetch occur within Washington County, Utah, near St. George.

LIFE CYCLE: The Shivwitz milk vetch is a perennial herb with a possible lifespan of nine years. Flowering occurs between April and late May. By the end of June the plant dries up; vestiges of dried plants may persist for several months. Perennial rootstock allows the Shivwitz milk vetch to survive dry years; in a drought year the plant may not emerge, instead remaining dormant.

THREATS: Urban development, off-road vehicle use, grazing, displacement by invasive plants, and mineral development all threaten the Shivwitz milk vetch.

POPULATION TREND: Shivwitz milk vetch populations are declining.

Photo © William Gray