LAS VEGAS BUCKWHEAT } Eriogonum corymbosum var. nilesii
DESCRIPTION: This buckwheat is a woody perennial shrub that grows up to four feet high and has a mounding shape. The subspecies is distinguished from closely related plants by leaves that are densely hairy on one or both surfaces and at least twice as long as they are wide, with dense hairs spread along the stem. Branches are woo lly haired and swollen at branch intersections. Flower clusters are one to four inches long with the flowers arranged in umbrella-like groups (called “corymbs”) at the ends of branches; the clusters branch widely and are sometimes thorny. The numerous flowers are small and yellow with small bract-like leaves at their bases.
HABITAT: The Las Vegas buckwheat has a distinct preference for soils with a high gypsum content. Typically, gypsum soil outcroppings occupied by Las Vegas buckwheat are sparsely vegetated with exposed soils covered with a cryptogamic (living) soil crust.
RANGE: This plant is confined to extremely limited areas in Clark and Lincoln counties, Nevada.
LIFE CYCLE: The Las Vegas buckwheat blooms in the fall, and this plant — which in other seasons is easy to overlook — provides a conspicuous flowery show.
THREATS: The biggest threat to the Las Vegas buckwheat is habitat destruction for urban developments — particularly in the Las Vegas Valley, on the Nellis Air Force Base, and near the Coyote Springs development. The plant is also imperiled by unmanaged off-road vehicle recreation on Bureau of Land Management lands, surface mining for gypsum, utility corridors along U.S. Highway 93, and a proposed coal-power energy plant in southern Lincoln County, Nevada.
POPULATION TREND: This plant is severely declining. More than 95 percent of its historic range has been destroyed, and only 859 acres of habitat remain that are not yet slated for development. Of these, only 50 acres are securely protected from destruction. Nine populations of plants are known, occupying 15 distinct sites.