ETWP; Determination of Endangered or Threatened Status for Five Desert Milk-vetchTaxa From California

The U.S. Fish and Wildlife Service (Service) determines endangered status pursuant to the Endangered Species Act of 1973, as amended, (Act) for three plants--Astragalus jaegerianus (Lane Mountain milk-vetch), Astragalus lentiginosus var. coachellae (Coachella Valley milk-vetch), and Astragalus tricarinatus (triple-ribbed milk-vetch); and threatened status for two plants, Astragalus lentiginosus var. piscinensis (Fish Slough milk-vetch), and Astragalus magdalenae var. peirsonii (Peirson's milk-vetch). Many taxa in the genus Astragalus, including the taxa covered by this rule, are endemic to habitats with specific substrate or hydrologic conditions and are, therefore, naturally limited in distribution by the availability of habitat. The five taxa in this rule occur in specific habitats within the three deserts of California; the Sonoran, Mojave, and Great Basin deserts. Astragalus jaegerianus occurs in granitic soils in San Bernardino County; A. lentiginosus var. coachellae occurs in the dune system of the Coachella Valley in Riverside County; A. lentiginosus var. piscinensis grows in moist alkaline flats near the border of Inyo and Mono counties; A. tricarinatus occurs in canyon slopes and washes in Riverside and San Bernardino counties and A. magdalenae var. peirsonii occurs primarily on dunes in Imperial County. These five plant taxa are threatened by one or more of the following--mining, urban development, off-highway vehicle (OHV) use and recreational development, pipeline maintenance, alteration of a wetland ecosystem, and low recruitment possibly due to rabbit herbivory or altered soil hydrology following fishery enhancement activities. Military training, and cattle grazing are potential threats. Two of the taxa are known from fewer than 200 individuals during the last decade. They are vulnerable to extinction from random natural events or unplanned activities that can destroy a substantial portion of remaining individuals. This rule implements the protection and recovery provisions afforded by the Act for these plants.