West Mojave Plan FEIR/S - Desert Managers Group

populations show intergradation with Opuntia basilaris var. basilaris.Regulatory Status: BLM Sensitive.Threats Affecting the Short-joint Beavertail Cactus: Nearly all of the occurrences ofshort-joint beavertail in the western Mojave Desert are on private land, and the primary threat isrural development in the Pinon Hills, Oak Hills, and Phelan areas in San Bernardino County, andsuburban development in and near Palmdale. Large-scale developments at Las Flores Ranch andSummit Valley may threaten this species or the intergrade populations.Off-road vehicle activity in the hills south and east of Phelan has damaged some habitat,and may eliminate plants.3.3.8.21 Triple-ribbed MilkvetchLife History: This species is only found in California and it is primarily known from thevicinity of Whitewater Canyon (the type locality) and from Dry Morongo Canyon alongHighway 62, as well as from scattered occurrences farther east in the Little San BernardinoMountains, including an anomalous, relatively high elevation, site at Key's Ranch in Joshua TreeNational Park. It is restricted to sandy or gravelly soils in arid canyons. It appears that no wellestablishedpermanent population of any size has ever been found.Population Status in the Planning Area: Most of the populations occur just outside ofthe planning area; but there are three locations within the western Mojave Desert: Little SanBernardino Mountains in Joshua Tree National Park (perhaps at Key's Ranch only), BigMorongo Canyon at the Riverside/San Bernardino counties line (several collections andobservations), in the Whitewater River drainage within the San Gorgonio Wilderness and in DryMorongo Canyon just north of the San Bernardino County line (several collections). There isadditional habitat along the southern part of the planning area that is not well explored that mayhave additional populations: in the upper reaches of Mission, Dry Morongo and Big MorongoCreeks, as well as in the western lobe of Joshua Tree National Park.Regulatory Status: Federal Endangered.Threats Affecting the Triple-ribbed Milkvetch: Threats are not well known becausethis species is not well studied and it is often difficult to find in remote and rugged areas.Vehicle travel in desert canyons and washes of the Little San Bernardino Mountains is apotential threat.3.3.8.22 White-Margined BeardtongueLife History: This species is disjunct from its primary range and is found in the sandfields and washes north of Pisgah Crater.Population Status in the Planning Area: This plant is found in the Pisgah Crater area.Twenty-two occurrences have been recorded. Three of these are on private lands. TheChapter 3 3-195