[3] Grown primarily by Quechua and Aymara farmers, oca has been a staple of rural Andean diets for centuries.

[3] Oca is essential to local food security because of its role in crop rotations and its high nutritional content.

Andean farmers, including the indigenous Quechua and Aymara people, cultivate numerous varieties of oca.

[5] Oca diversity may be described with respect to morphological characters, local cultivar names, or molecular markers.

Oca-growing communities often name varieties based primarily on tuber morphology[8] and secondarily on flavor.

[2] For example, common names may include ushpa negra (black ash) or puka panti (red Cosmos peucedanifolius).

Molecular markers, such as allozymes (e.g., del Río, 1999[10]) and inter-simple sequence repeats (e.g., Pissard et al., 2006[11]), show oca diversity to be low relative to other crops, probably because of its vegetative mode of propagation.

[11][12] Oca is cultivated primarily for its edible stem tuber, but the leaves and young shoots can also be eaten as a green vegetable.

[13] Andean communities have various methods to process and prepare tubers, and in Mexico oca is eaten raw with salt, lemon, and hot pepper.

Cultivars in this use category are referred to in Quechua as khaya (name of the dried, processed product) or p'usqu (sour/fermented),[12] and in Aymara as luk’i.

[2] The traditional Andean preparation methods for this use category are also geared towards reducing the oxalate level of the harvested vegetable, but without dehydration.

[18] Oca is one of the important staple crops of the Andean highlands due to its easy propagation and tolerance for poor soil, high altitude, and harsh climates.

[12] Its highest abundance and most extraordinary diversity are in central Peru and northern Bolivia, the probable area of its domestication.

[3] Oca grows with very low production inputs, generally on plots of marginal soil quality, and tolerates acidities between about pH 5.3 and 7.8.

[22] Furthermore, on the rare occasion that oca plants do produce fruit, their loculicidal capsules dehisce spontaneously, making it difficult to harvest seed.

[21] Within this system, q’allpa is a Quechua term that signifies soil previously cultivated and prepared for the planting of a new crop.

[23] Monoculture predominates, but interplanting with several other tuber species, including mashua and olluco, in one field is common in Andean production.