RHUS

genus of about 150 species of shrubs, small trees, and vines, of the cashew family (Anacardiaceae), including the popular sumacs (see sumac). Authorities disagree over the inclusion of poison oak, poison sumac, and poison ivy (q.v.), which are often classified in a separate genus, Toxicodendron. Several species are of local economic value. The wax tree (R. succedanea) has berries that yield a commercial wax and a sap that provides a natural lacquer. The varnish tree, or lacquer tree (R. verniciflua), source of Japanese lacquer, is poisonous to the touch, as is the North American poison sumac (R. vernix). Fruits of many sumacs and of sourberry, or lemonade berry (R. integrifolia), can be brewed into a lemony drink. Both sourberry and sugarbush (R. ovata) are cultivated as ornamentals in southern California.