 "campylon", the Mount Hamilton thistle, is uncommon, but occurs in widely distributed locations in Santa Clara, Alameda and Stanislaus County, in the southeastern San Francisco Bay Area.Elevations of this variety are from in the southern Santa Clara Valley and the Diablo Range, including Mount Hamilton.As with the other species varieties, the Mount Hamilton thistle prefers moist areas on serpentine soil slopes including seeps, riparian stream environments, and other wetlands.