The Pistachio a member of the cashew family, is a small tree originating from Central Asia and the Middle 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 be distinguished by their geographic distributions (in the wild) and their seeds which are much smaller and have a soft shell.
The shell of the Pistachio is naturally a beige color, but it is sometimes dyed red or green in commercial pistachios. Originally, dye was applied by importers to hide stains on the shells caused when the seeds were picked by hand. Most Pistachios are now picked by machine and the shells remain unstained, making dyeing unnecessary except to meet ingrained consumer expectations.