Pachyrhizus Rich. ex DC.
Pachyrhizus is a small genus of five or six species of tropical and subtropical plants growing from large, often edible taproots.
The jícama (English pronunciation: /ˈhɪkəmə/) or yam bean (P. erosus) is a vine widely grown for its large (10-15 cm diameter and up to 20 kg weight), spherical or elongated taproot. After removal of the thick, fibrous brown skin, the white flesh of the root can be eaten cooked or raw. Crisp, moist, and slightly sweet, the flesh draws comparison with that of the apple. In contrast to the root, the remainder of the jícama plant is very poisonous.
Goiteño, nupe, jacatupe or Amazonian yam bean (Pachyrhizus tuberosus) is an annual vine that is characterized by a wrapped and herbaceous stem and a ligneous base. It has white and lilac flowers, pods from 10 to 20 cm in length and beans with a high protein content (32%). Each plant has two or more tubercles from 15 to 25 cm in length that are succulent, sweet and rich in starch and protein (9%). They are consumed both raw and cooked. The leaves (20 to 24% protein) and pods are also edible. This plant prospers in acid soils in South America's tropical rainforests. It is cultivated by the native peoples of the Amazonia, who practice shifting horticulture.
The ahipa or ajipa or Andean yam bean (Pachyrhizus ahipa) is very similar to the jicama and goitenyo in characteristics and uses. Unlike the jícama, it is not a vine and it grows up 2000 meters in the highest Bolivian mountains. The root is smaller and more elongated. It is little known outside of the Andes, where it is mostly grown for personal or local consumption. In the nineteenth century, British scientists introduced ahipa to the West Indies, where it is also enjoyed by the residents of those islands (Vietmeyer 1992).
Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License