PISTA'CIA, a genus of trees of the natural order anacardiacca, having dicecious flowers without petals, and a dry drupe with a bony stone. The PISTACIA, Or PISTACHIO TREE (P. vera), is a small tree of about 20 ft. high, a native of Persia and Syria, but now culti vated in all parts of the s. of Europe and n. of Africa, and in many places naturalized. It has pinnate leaves, with about two pair of ovate leaflets, and an odd one; flowers in vaccines; fruit ovate, and about the size of an olive. The stone or nut splits into two valves when ripe; the kernel, which is of a bright green color, is very oleaginous, of a delicate flavor, and in its properties very much resembles the sweet almond. In the s. of Europe and in the east, pistachio nuts are much esteemed; but as they very readily become rancid, they are little exported to other countries. They are sometimes called green almonds. Oil is expressed from them for culinary and other uses. In culti vation one male tree is allowed to five or six fertile ones. The tree produces flowers and even fruit readily enough "-in the s. of England, but the summers are not warm enough to ripen the fruit, and the tree is apt to be destroyed by a severe fro.4.—TnE MAsTic TREE, or LENTISK (P. lentiscus), yields the gum-resin called mastic (q.v.). It is a native of the countries around the Mediterranean.—The TURPENTINE TREE (P. terebin
thus) yields the turpentine (q.v.) known in commerce as Cyprus turpentine, Chian turpen tine, or Scio turpentine, which is of a consistency somewhat like that of honey, a greenish yellow color, an agreeable odor, and a mild taste, and in its properties resembles the turpentine of the Conifera . but is free from acridity. It is obtained by making incisions in the trees, and placing stones for the turpentine to flow upon, from which it is scraped in the morning, before it is liquified again by the beat of the sun. The tree is about 30 or 35 ft. in height, and has pinnate leaves, of about three pair of leaflets and an odd one; the flowers in compound racemes, the fruit nearly globular. The kernel of the fruit is oleaginous and pleasant.—The BATOUM TREE (P. Attantica). a round-headed tree of about 40 ft. in height, a native of the n. of Africa, produces a fruit much used by the Arabs; and a gum-resin of pleasant aromatic smell and agreeable taste, which exudes from its stem and branches, is chewed to clean the teeth and impart a pleasant smell to the breath.—The fragrant oil of the kernels of P. olcosa, a native of Cochin China, is used by the people of that country to impart a perfume to ointments.