Cassava is a tropical shrub whose large thick roots provide the third largest source of food carbohydrate in the tropics after rice and maize. It is a woody shrub of the spurge family and is native to South America.
Although a perennial plant, cassava is extensively cultivated as an annual crop in tropical and subtropical regions. The underground part of the cassava plant produces a tuber crop like potatoes and yams. These roots have a shape similar to sweet potatoes and are very rich in carbohydrate. However, they are poor in protein and most other nutrients except for small amounts of calcium, phosphorous, and vitamin C.
It is essential to peel and thoroughly wash cassava and never eat it raw. It contains dangerous levels of cyanide unless it is properly cooked before eating it. There are about 2,000 plant species that contain some level of cyanide. Neither animals nor humans would be tempted to eat most of them, so they don't commonly present any danger.
Cassava is one of the most drought-tolerant crops and is capable of growing on marginal soil and doesn't require much fertilizer. Most cassava is grown in West Africa and the joining Congo basin, tropical South America and South and Southeast Asia.
Cassava is predominately consumed after boiling or baking, but large quantities are also used to extract the starchy pulp, called tapioca.
Tapioca is eaten as a pudding or used as a thickening agent. It is also used as animal feed as well as for industrial purposes. In Africa, it is used to make a flour that can be used for all kinds of baked goods from bread and cookies to pancakes. In Asia, it is used in the production of monosodium glutamate (MSG), a flavoring used in cooking. The juice that can be extracted from the pulp is fermented into a strong liquor called kasini.
Nigeria is the world's largest producer of cassava, while Thailand is the largest exporter of cassava starch.