Vermilacinia polymorpha is a fruticose lichen infrequently found on Santa Catalina Island in the Channel Islands of California and along the mainland coast in Ventura and Orange counties. It has also been indicated to occur south into northwestern Baja California without reference to specimens to support its range extension, and shown to occur on the Vizcaíno Peninsula in central Baja California on a distribution map in a lichen flora, without reference to specimen data; however, specimen data from other sources indicate it does occur as far south as Punta Santa Rosalillita on the main peninsula of Baja California., and also reported from Guadalupe Island