[Wikipedia] Western and southern Europe, northwest Africa, and southwest Asi: Along the west coast of the United States and Canada, from California to British Columbia,[8] non-native English Holly has proved very invasive, quickly spreading into native forest habitat, where it thrives in shade and crowds out native species. It has been placed on the Washington State Noxious Weed Control Board's monitor list, and is a Class C invasive plant in Portland. It is an invasive species on the West Coast of Canada[8] and the United States as well as in Hawaii. (link added by Mary Ann Machi)