Threatened by carbonate mining, vehicles, road construction, and residential development. See Synoptical Flora of North America 1(2):221 (1884) for original description, and Fremontia 16(1):20-21 (1988) for discussion of mining threats.
California Native Plant Society (CNPS).
Inventory of Rare and Endangered Plants (online edition, v8-02).
California Native Plant Society. Sacramento, CA. Accessed on
.