[Wikipedia] Origin, Escape from Cultivation, Invasive Info: It is native to a section of Eurasia from North Africa to the Iranian Plateau, where it was once common.[11] Because other trees were rare, it was the only good source of wood and was overharvested, reducing its current distribution.[11] It is a common tree in mountain forests in Iran,[11] and it is "characteristic" of the landscape in parts of Algeria outside the Sahara. Pistacia atlantica is planted as an ornamental shadebearing and drought-tolerant landscape tree in gardens and parks.[18] In California it is imported to use as rootstock for cultivated pistachio trees (Pistacia vera).[19] Both introductions have led to its escape and current status as an occasional invasive species in California. (link added by Mary Ann Machi)