Astragalus humillimus A. Gray

Astragalus humillimus A. Gray. Astragalus humillimus is a rare species of milkvetch known by the common name Mancos milkvetch. It is native to a small section of the Four Corners region of the United States, where it can be found in Montezuma County, Colorado, and San Juan County, New Mexico. There are about nine small, localized populations on sandstone rimrock ledges on the mesas. The plant occurs in a region that is being developed for oil and gas exploration, and altered by associated activities such as road construction and pipeline installation. It is a federally listed endangered species.