Part of the cashew family, Pistacia is a genus containing 11 species of flowering plants. Mostly native to Europe and Asia, single species of the genus can be found natively in North America and the Canary Islands. Pistacia species may be trees or shrubs and some are used as landscaping trees or for their nuts, commonly called pistachios.
Members of the Pistacia genus are usually deciduous and able to survive in temperatures below freezing. They require bright sunlight and are often drought tolerant. Although they can survive in many soils, they do best in deep, well-drained areas. These plants have gender, and only when both male and female plants are present do trees bear fruit.
Two species, Pistacia lentiscus and Pistacia chinensis are primarily used for decorative purposes. Commonly called a mastic tree, lentiscus is an irregularly shaped evergreen shrub, but can be trained to appear tree-like. The leaves are oblong, about 2 inches (5 cm) long, and form three to five pairs on either side of the stem. Fruits are normally red or black berries. When left as a shrub, this plant is good for hedging, otherwise placement near a patio or a pool is ideal.
The mastic tree also produces a resin that has several medical uses. Called mastic, this resin has been used in dentistry to fill cavities and in surgery as a protective covering for wounds. Since the 13th century, it has been used in some countries to treat upset stomachs, as well as for high blood pressure.
The Pistacia chinensis or Chinese pistachio, is native to China but has been successfully transplanted to other parts of the world. The Chinese pistachio is especially prized for its brilliant red, yellow, or orange leaf coloring in autumn and the natural oval-shaped growth of its branches. The tree grows 25-35 feet (7.6-10.6 m) tall and produces small blue or red fruit. Its flowers are also small and greenish.
Used for commercial pistachio production, Pistacia vera is generally grown in orchards in the southwestern United States. Often called simply a pistachio plant, these trees may be up to 30 feet (9.1 m) tall, with grayish leaves. The nut is actually the seed of the red fruits, which appear on trees in grape-like clusters. The oblong nuts are encased in a ivory colored shell, and in good growing seasons, the shell will naturally split lengthwise before they are packaged and distributed. Pistachio nuts are oil-rich nuts, with 55 percent of their structure actually oil.