Known from approximately twenty occurrences. Threatened by mining and vehicles, and potentially threatened by renewable energy development. See Bulletin of the California Academy of Sciences 1:152 (1885) for original description, and University of California Publications in Botany 32:235-314 (1961) for taxonomic treatment.
California Native Plant Society (CNPS).
Inventory of Rare and Endangered Plants (online edition, v8-01a).
California Native Plant Society. Sacramento, CA. Accessed on
.