Pistachios are the edible, green seeds of the Pistacia vera tree, native to Central Asia and the Middle East. They are known for their distinct flavor, a combination of sweet, slightly bitter, and mild nutty notes, and are often roasted and salted for consumption. Botanically, a pistachio is the seed of a drupe, a fleshy fruit with a hard outer shell that splits open when ripe to reveal the green seed inside.