Probably consists of northern and southern unrecognized subspecies. Habitat lost to construction of San Antonio Reservoir; also threatened by urbanization, vehicles, grazing, feral pigs, alteration of fire regimes, road construction, road maintenance, and non-native plants.
California Native Plant Society (CNPS).
Inventory of Rare and Endangered Plants (online edition, v8-01a).
California Native Plant Society. Sacramento, CA. Accessed on
.