Rare Plants

A total of 127 populations of 30 rare plant taxa have been documented to occur on the Hanford Site. A majority of these populations and taxa occur on the Monument. In addition, 3 taxa (two species and one variety) had not previously been described and are considered “new” to science; Eriogonum codium (Umtanum Ridge desert buckwheat)—a Federal Candidate Species for Threatened and Endangered listing, Lesqurella tuplashensis (White Bluffs bladder-pod), and Astragalus comjunctus var. rickardii (Rattlesnake mountain milk-vetch). Many of these populations of plants are endemic to the area, several were not previously known from Washington State, or otherwise of botanical interest and potentially of conservation and management concern. Little is known about the ecology, requirements or population dynamics of these species. Fire may be one of the greatest threats to many of these plants, mortality of Umtanum Ridge desert buckwheat was documented following a 1997 fire. There are currently no federally listed plants on the Monument.