Streptanthus oliganthus

Streptanthus oliganthus is known from eastern California and adjacent western Nevada, in the northern White Mountains, Sweetwater Mountains, Bodie Hills, Masonic Mountain, and Wassuk Range, with disjunct occurrences in the Shoshone Mountains and Toiyabe Range. There are approximately 24 occurrences but at least 13 are historical. The species occurs mostly on U.S. Forest Service lands. Overall occurrences have few serious threats as they are in remote locations and on steep, inaccessible slopes, where they are relatively protected; a few may be threatened by mining and mineral exploration, off-road vehicle use, road construction and maintenance, concentrated livestock use, military activities, and fire related to exotic plants.

Streptanthus oliganthus is known from eastern California and adjacent western Nevada, in the northern White Mountains, Sweetwater Mountains, Bodie Hills, Masonic Mountain, and Wassuk Range, with disjunct occurrences in Nye County, Nevada in the Shoshone Mountains and Toiyabe Range (Hickman 1993, Rollins 1993, Holmgren et al. 2005). The species occurs in the counties of Mono and adjacent Tuolumne in California and Esmeralda, Lyon, and Mineral Counties in Nevada. Range extent is calculated at 3,588 sq km when historical occurrences are excluded and 4,011 sq km when included.

In California there are 21 occurrences, of which 13 are historical, but possibly extant considering they are in remote areas. More occurrences are likely to be found, especially in these more remote regions (K. Lazar, pers. comm., 2020). Approximately 14 occurrences are known from Nevada at a 1 km separation distance but some of these are likely continuous with occurrences in California. The species is not yet systematically surveyed in Nevada (Morefield 2001).

Many of the occurrences, including historical records, occur in remote areas, sometimes on steep slopes with limited access, and are believed to have few serious threats. This species shows resistance to or affinity for disturbance, as at least one population is noted as growing well on a roadside and another is growing well on an old mine dump (K. Lazar, pers. comm., 2020). Roadside occurrences, while likely favoring disturbance, could face some road maintenance or construction activities that would be detrimental. Some occurrences in California and Nevada are potentially threatened by mining, through proximity to mining claim stakes but this is not a currently actie threat. One occurrence is potentially threatened by Marine Corp activities. A few occurrences in Nevada are threatened by off-road vehicle use, soil disruption from concentrated livestock use, and competition and fire hazard from introduced exotics.