Don't think that there's only one variety of pistachio. There are round ones, long ones, red ones and green ones. These slim, oblong nuts, ranging from pale, creamy yellow to dark green, are kernels of small olive-like fruits. They grown in clusters, and are cultivated in the Middle East, some Mediterranean countries, and California.

The pistachio tree is a high tree that requires well-drained soil and hot summers (above 30° C) and cold winters (-7° C). It begins to produce after six years, though only reaches maturity after 12 years. Documents place its origins in western Asia and Asia Minor, where it was known as far back as 7000 BC.