[beta.floranorthamerica.org] Range, Similarity/Difference to Other Species: Castilleja lacera is found in a wide range of elevations in the central and northern Sierra Nevada region and in the Siskiyou Mountains region of northwestern California and southwestern Oregon. Reports from the Coast Ranges north of the San Francisco Bay region and south of the Siskiyou region in western California are referable to other yellow-flowered annuals, including C. ambigua, C. rubicundula var. lithospermoides, Triphysaria eriantha subsp. eriantha, and T. versicolor subsp. faucibarbata. Although most similar to C. rubicundula, C. lacera is somewhat smaller in stature and flower size. It is also easily confused with yellow-flowered populations of C. tenuis, which has smaller flowers and an included stigma. Two chromosome numbers are known for this species, the more northern populations being diploid, and those to the south having an apparently aneuploid count of 2n = 22, which is unique in the genus. (link added by Mary Ann Machi)