The Cashew Nut Tree

One solitary cashew hangs from the flowers on the cashew nut tree, a relic of a past and showing me what a growing cashew nut looks like.

The cashew tree (Anacardium occidentale) is a tropical evergreen tree that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as 14 metres. The one here is very tall and mature.  The cashew seed is commonly considered a snack nut (cashew nut) eaten on its own, used in recipes, or processed into cashew cheese or cashew butter.  Like the tree, the nut is often simply called a cashew.

 As well as the nut and fruit, the plant has several other uses. The shell of the cashew seed yields derivatives that can be used in many applications including lubricants, waterproofing, paints, and, starting in World War II, arms production. The cashew apple is a light reddish to yellow fruit, whose pulp and juice can be processed into a sweet, astringent fruit drink or fermented and distilled into liquor.

The true fruit of the cashew tree is a kidney– or boxing-glove–shaped drupe that grows at the end of the cashew apple. The drupe first develops on the tree and then the pedicel expands to become the cashew apple.  The drupe becomes the true fruit, a single shell-encased seed, which is often considered a nut in the culinary sense. The seed is surrounded by a double shell that contains an allergenic phenolic resin,^[3]anacardic acid—which is a potent skin irritant^[6] chemically related to the better-known and also toxic allergenic oil urushiol, which is found in the related poison ivy and lacquer tree.