Known from fewer than 20 occurrences. Plants from MRN Co. are apparently not hybrids with D. decorum ssp. decorum; hybridizes with D. nudicaule. Threatened by development, grazing, and road maintenance. Possibly threatened by horticultural collecting. See Bulletin of the Southern California Academy of Sciences 2:68-69 (1903) for original description, and Conservation Biology 15(6):1608-1618 (2001) for information on origin.