- Scientific name: Anacardium occidentale
- Family: Anacardiaceae
Tree up to 12m tall. Trunk rarely straight, smooth brown bark with occasional dark brown-black cracks where sap may have emerged. Leaves leathery (coriaceous), up to 22cm long, obovate to broadly elliptic. Collections of flowers (inflorescences) furry panicles or corymbs with each flower stalk measuring 2-5cm. Individual flowers small; smell of mango when crushed; petals linear, pale green striped with dark pink-red becoming entirely red; off-centre style.
- The cashew fruit is not a nut, but instead more of a drupe (a seed contained in a hard coating surrounded by flesh). This drupe forms first at the end of the inflating pedicel, which in turn forms the cashew apple.
- These fast-growing, drought-tolerant trees produce ‘nuts’ after three years and can live for 50.
- Cashews are more expensive than peanuts because roasting, shelling and cleaning of the kernels is a delicate and laborious process and the liquor produced by the shells is highly corrosive.
Where it grows
The cashew is native to tropical and subtropical South America, but is now cultivated worldwide. It can grow in warm temperate forests, dry tropical forests and tropical rainforests. Vietnam is the largest producer of cashews in the world; India, Mozambique and Tanzania are also major producers.
Cashew nuts are an extremely popular snack and ingredient worldwide. In Goa, India the swollen pedicel (cashew apple) is mashed and brewed into an alcoholic drink.
The shells produce cashew-nut shell liquor (CNSL), which is used in the tropics to treat ringworm and warts, and is also used globally in marine paints, heatproof enamels, brake pads and more recently as a resin in ‘ecocomposites’ (traditionally bio-composites are made from plant fibres, such as hemp, embedded into fossil-fuel-based resins).
Some African tribal cultures use cashew nuts as part of the scarification process, where people permanently mark their skin by cutting it. Ash, charcoal and cashew nuts are used to irritate wounds and get them to swell up so cuts heal as raised scars.
Cashews are generally pollinated by flying insects, but not all insects are helpful: ants have been studied 'ruining' the flowers.
- Corymb: flat-topped branched flower stalk.
- Obovate: two-dimensionally egg-shaped with widest part at the apex.
- Panicle: branched flower stalk.
- Pedicel: flower/floret stalk.
- Style: the tube connecting ovary and stigma.