[Wikipedia] Distribution, Description: Calochortus umbellatus is a flowering plant in the lily family found only in California in the United States.[3][4] The common name for this species is Oakland mariposa lily or Oakland star-tulip. Distribution The species is a California endemic of limited distribution.[5] It grows primarily in the San Francisco Bay Region, often on serpentine soils,[6] with a few isolated populations in Humboldt, Mendocino, and Nevada Counties.[7] Description Calochortus umbellatus is a branching perennial herb up to 25 cm tall. Inflorescence is sub-umbellate with 3-10 white or pale pink flowers.[8] This species is included on the California Native Plant Society list 4.2 of rare and endangered plants.[9] (link added by Mary Ann Machi)