Cashews Are Not Actually Nuts

Botanically speaking, cashews are seeds, not nuts. They grow attached to the bottom of cashew apples (which are edible fruits) and are encased in a double shell containing anacardic acid - the same irritating chemical found in poison ivy. This toxic shell must be carefully removed through a heating process, which is why you never see cashews sold in their shells like other nuts. The cashew apple itself is eaten fresh or used to make beverages in many tropical countries, but it's too delicate to export.