Cassava (Manihot esculenta), also called yuca or manioc, is a woody shrub of the Euphorbiaceae (spurge family) native to South America. Cassava is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. Nigeria is the world’s largest producer of cassava.
Cassava is the third-largest source of carbohydrates for meals in the world. Cassava is classified as sweet or bitter depending on the level of toxic cyanogenic glucosides; improper preparation of bitter cassava causes a disease called konzo. Nevertheless, farmers often prefer the bitter varieties because they deter pests, animals, and thieves.
Cassava is sometimes spelled cassaba or cassada. In English-language publications, the plant may be occasionally called by local names, such as mandioca, aipim, or macaxeira (Brazil), yuca (Bolivia, Colombia, Ecuador, The Dominican Republic, Panama, Peru, Venezuela), kassav (Haiti), mandi´o (Paraguay), akpu, ege or ugburu (Nigeria), bankye (Ghana), mogo or mihogo (Swahili-speaking Africa), pondu in (Lingala-speaking Africa), kappa (India), maniok (Sri Lanka), singkong (Indonesia), ubi kayu (Malaysia), kamoteng kahoy or balanghoy (Philippines), mushu (China), man sampalang (Thailand), củ sắn or khoai mì (Vietnam), and manioke , tapioka or manioka (Polynesia).
The cassava root is long and tapered, with a firm homogeneous flesh encased in a detachable rind, about 1mm thick, rough and brown on the outside. Commercial varieties can be 5 to 10 cm in diameter at the top, and around 15 cm to 30 cm long. A woody cordon runs along the root’s axis. The flesh can be chalk-white or yellowish. Cassava roots are very rich in starch, and contain significant amounts of calcium (50 mg/100g), phosphorus (40 mg/100g) and vitamin C (25 mg/100g). However, they are poor in protein and other nutrients. In contrast, cassava leaves are a good source of protein and rich in the amino acid lysine, though deficient in methionine and possibly tryptophan.
Wild populations of M. esculenta subspecies flabellifolia, shown to be the progenitor of domesticated cassava, are centered in west-central Brazil where it was likely first domesticated no more than 10,000 years BP. By 6,600 BC, manioc pollen appears in the Gulf of Mexico lowlands, at the San Andres archaeological site. The oldest direct evidence of cassava cultivation comes from a 1,400 year old Maya site, Joya de Cerén, in El Salvador. although the species Manihot esculenta likely[weasel words] originated further south in Brazil and Paraguay. With its high food potential, it had become a staple food of the native populations of northern South America, southern Mesoamerica, and the Caribbean by the time of the Spanish conquest, and its cultivation was continued by the colonial Portuguese and Spanish. Forms of the modern domesticated species can be found growing in the wild in the south of Brazil. While there are several wild Manihot species, all varieties of M. esculenta are cultigens.
Cassava was a staple food for pre-Columbian peoples in the Americas, and is often portrayed in indigenous art. The Moche people often depicted yuca in their ceramics