Oca
Oxalis tuberosa

Family: Oxalidaceae

What it is like

A small annual herb up to 30 cm high with leaves of 3 leaflets. The stems are round and succulent. The leaves are spirally arranged. The flowers are orange-yellow. Three different kinds of flowers occur associated with three different kinds of tubers. The tubers have scales which cover long deep eyes. Tubers vary considerably in shape. The tubers are wrinkled and vary in colour between red, orange, yellow, or white. Some varieties have bitter tubers. They are about 5-8 cm long and 2-4 cm across. The plant rarely sets seed in the field but seed can be produced by self pollinating. When seed form, they occur in 5 celled locules with 1-3 tiny seeds in each.

There are about 500 Oxalis species.

Where it is found

A temperate plant. It mostly grows in the Andes from Colombia to Chile at between 3,500 and 3,800 m altitude. The plant is frost hardy. They grow in the high altitude tropics. (2,800 - 4,560 m in the Andes). In Argentina it grows between 1,200-2,800 m above sea level. In the hot tropical lowlands, tubers perish quickly. A daylength of 9 hours is best for tuber formation. Vegetative top growth occurs under long day lengths. It suits hardiness zones 7-11.

Countries/locations it is found in

Andes, Argentina, Australia, Bolivia (country/location of origin), Britain, Central America, Chile, Colombia, Ecuador, Europe, Mexico, New Zealand, North America, Pacific, Papua New Guinea, Peru, South America, Tasmania, USA, Venezuela

How it is used for food

The tubers are acid when fresh but are dried slightly then cooked and eaten. The bitter kinds are freeze dried and stored for later use. They can be used in soups and stews. The young leaves and shoots can be eaten. CAUTION Fresh tubers contain calcium oxalate.

It is a commercially cultivated vegetable. "Stew without chunu is like life without love!" It has only recently been introduced to Papua New Guinea to try it out. It is an important food in high altitude areas in the Andes.

Edible parts

Flowers, leaves, root, tubers, vegetable

How it is grown

Plants are grown from tubers or cut pieces of tubers which contain 1-3 eyes. Planting is normally done at the beginning of the rainy season and plants are weeded and soil mounded around them. A spacing of 20-40 cm x 20-36 cm is recommended.

Tubers mature in about 8 months. Average yields in the Andes are about 3.7 t / ha. After digging tubers are cured in the sun for several days.

Its other names

Local names

New Zealand yam, Peru, Samoa, Oqa, Apio blanca, Cuiba, Cuiva, Huisisai, Ibias, Macachin, Miquichi, New Zealand yam, Quiba, Ok'a, Apilla, Ibia, Ruba, Timbo, Quiba, Papa roja, Papa colorada, Papa extranjera, Truffette acide

Synonyms

Oxalis crenata Jacq.; Oxalis crassicaulis Zuccarini; Oxalis arracacha G. Don;