Occurrences from SAC Co. (480C) and CCA Co. (481C) are introduced. Seriously threatened by mining, agriculture, industrial development, and non-native plants. Recovery work in progress. Protected in part at Antioch Dunes NWR (USFWS). See Aliso 2:81 (1949) for original description, Four Seasons 3(1):2-4 (1969) for threat information, and Biological Conservation 65:257-278 (1993) for population biology.