The pistachio a member of the cashew family, is a small tree originating from Central Asia and theMiddle East.The tree produces seeds that are widely consumed as food.
Pistacia vera often is confused with other species in the genus Pistacia that are also known as pistachio. These other species can bedistinguished by their geographic distributions (in the wild) and their seeds which are much smaller and have a soft shell.
The bush grows up to 10 m (33 ft) tall. It has deciduous pinnate leaves 10–20 centimeters (4–8 inches) long. The plants are dioecious, with separate male and female trees. The flowers are apetalous and unisexual, and borne in panicles.
The fruit is a drupe, containing an elongated seed, which is the edible portion. The seed, commonly thought of as a nut, is a culinary nut, not a botanical nut. The fruit has a hard, creamish exterior shell. The seed has a mauvish skin and light green flesh, with a distinctive flavor. When the fruit ripens, the shell changes from green to an autumnal yellow/red, and abruptly splits part way open (see photo). This is known as dehiscence, and happens with an audible pop. The splitting open is a trait that has been selected by humans. Commercial cultivars vary in how consistently they split open.
Each pistachio tree averages around 50 kilograms (110 lb) of seeds, or around 50,000, every two years.