Cashew is the common name of a tropical evergreen tree Anacardium occidentale, in the family Anacardiaceae. It is the source of the cashew nut (often simply called a 'cashew') and the cashew apple. The tree can grow as tall as .
The species is native to South America. The dwarf cultivars, growing up to , are the most profitable, maturing sooner and producing greater yields. In 2023, 3.9 million tons of cashew nuts were harvested globally, led by the Ivory Coast and India.
The nut is edible and is eaten on its own as a snack, used in recipes, or processed into cashew cheese or cashew butter. The cashew apple, an accessory fruit, is a light reddish to yellow fruit, the pulp and juice of which can be processed into a sweet, astringent fruit drink or fermented and distilled into liquor. Additionally, derivatives from the shell are used in products such as varnishes, lubricant, and paints.
The cashew tree is large and evergreen, growing to tall, with a short, often irregularly shaped trunk. The leaves are spirally arranged, leathery textured, elliptic to obovate, long and broad, with smooth margins. The flowers are produced in a panicle or corymb up to long; each flower is small, pale green at first, then turning reddish, with five slender, acute petals long. The largest cashew tree in the world covers an area around and is located in Parnamirim, Brazil.
The fruit of the cashew tree is an accessory fruit (sometimes called a pseudocarp or false fruit). What appears to be the fruit is an oval or pear-shaped structure, a hypocarpium, that develops from the pedicel and the receptacle of the cashew flower. Called the cashew apple, better known in Central America as , it ripens into a yellow or red structure about long.
The true fruit of the cashew tree is a kidney-shaped 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, anacardic acid - which is a potent skin irritant chemically related to the better-known and also toxic allergenic oil urushiol, which is found in the related poison ivy and lacquer tree.
The English name derives from the Portuguese name for the fruit of the cashew tree: (), also known as , which itself is from the Tupi word , literally meaning "nut that produces itself".
The generic name Anacardium is composed of the Greek prefix ana- (), the Greek cardia (), and the Neo-Latin suffix . It possibly refers to the heart shape of the fruit, to "the top of the fruit stem" or to the seed. The word anacardium was earlier used to refer to Semecarpus anacardium (the marking nut tree) before Carl Linnaeus transferred it to the cashew; both plants are in the same family. The epithet occidentale derives from the Western (or Occidental) world.
The species is native to tropical South America and later was distributed around the world in the 1500s by Portuguese explorers. Portuguese colonists in Brazil began exporting cashew nuts as early as the 1550s. The Portuguese took it to Goa, formerly Estado da ÃÂndia Portuguesa in India, between 1560 and 1565. From there, it spread throughout Southeast Asia and eventually Africa.