Pistachio nut

Pistachio nut (Pistacia vera), seed of the pistachio tree in the cashew family. Pistachio trees grow in western Asia, the Mediterranean, and southwestern U.S. The nut, which is about 1 in (2.5 cm) long, consists of a hard shell, smooth husk, and an edible green kernel. The kernel, which has a mild flavor, can be eaten whole. When ground, kernels are used to flavor foods; when pressed, they produce a cooking oil.