The genus Fremontodendron (Sterculiaceae) is endemic to California and Arizona in the United States and to Baja California of Mexico. Fremontodendron is considered to consist of two distinct and geographically localized species, F. decumbens and F. mexicanum, and a widespread, highly polymorphic species, F. californicum. Studies of morphological variation, including principal components analysis, did not support the recognition of infraspecific taxa in F. californicum. Fremontodendron Coville is a genus of shrubs and small trees endemic to the western United States and northwestern Mexico. It is a common but localized component of chaparral commu-