The cashew is the seed of a tropical tree, Anacardium occidentale, which originated in Central and South America (hence the name, which comes from caju or acaju in the language of the Tupi people of the Amazon basin), but is now grown extensively in Africa and India. The seed itself, which somewhat resembles a kidney-shaped peanut, grows as an incongruous-looking sprout at the extremity of a pear-shaped fruitlike receptacle (known as a cashew-apple); it was first described in English by William Dampier in A New Voyage Round the World (1703): ‘The Cashew is a Fruit as big as a Pippin, pretty long, and bigger near the Stem than at the other end. … The Seed of this Fruit grows at the end of it; 'tis of an Olive Colour shaped like a Bean.’
The shell of the nut has three layers, and its extraction is a highly labour-intensive business. The middle layer contains an acrid brown oil.
Subjects: Medicine and Health.