Origin
Probably Peru. Andean regions of Peru and Ecuador

Historical background
Archaeological finds in Peruvian tombs (BRUCHER 1989) testify to its early use as a root vegetable in Pre-Columbian times. Its cultivation is mentioned in 1786 (ALTOLAGUIRRE). In 1659, 4 pounds of the tuber were sold for one 'real' (VELEZ & VELEZ 1990).

Occurrence
It is mainly cultivted in the Andean valleys of the Cloud forest regions in Colombia and Venezuela, as well as in the Cordillera de la Costa. Outside of Venezuela it is cultivated in the West-Indies, Central America, Africa, Sri Lanka, and on an industrialized range in the south of Brazil.

Ethnobotanical and general use
The roots which are mainly used for food reach 8-20 cm in length and 6-10 cm in thickness.

Nutritional use
The tubers, which are eaten, correspond to modified roots and serve as a food reservoir for the plant; the parenchyma functions as a storage tissue, mainly of starch (about 10-25 %). The tubers have an aromatic taste, due to the content of volatile oils in the secretory canals (e.g. carvone). They are eaten as a vegetable like potatoes, being used in stews and soups, boiled or fried, mashed as puree and even as a sweet cake. The plant is much used in the Venezuelan cuisine and recommended as palatable, tasty, wholesome, aromatic and abundant. The famous botanist DECANDOLLE considered the plant as a genuine enrichment of French cuisine! Besides, roots and leaves are a food for cattle and other animals.

Medical use
The leaves of the plant have antiinflammatory properties and are often used in the treatment of dental abscesses. The root has a slightly laxative effect.

Chemical contents
Volatile oils (carvone). The tuber is rich in carbohydrates (starch 25 %), calcium, phosphorus, niacin, vit. C and A., potash and sodium.

South American medicinal plants : botany, remedial properties, and general use / I. Roth, H. Lindorf. Berlin ; New York : Springer, c2002. -- p. 492.