From Cookipedia(Redirected from Arracha)
Apios Americana, sometimes called the potato bean, hopniss, Indian potato or groundnut (but not to be confused with other plants sometimes known by the name groundnut) is a perennial vine native to eastern North America, and bears edible beans and large edible tubers. It grows to 3-4 m long, with pinnate leaves 8-15 cm long with 5-7 leaflets. The flowers are red-brown to purple, produced in dense racemes. The fruit is a legume (pod) 6-12 cm long.
The tubers are crunchy and nutritious, with a high content of starch and especially protein. The plant was one of the most important food plants of pre-European North America, and is now being developed for domestication.
There is a very comprehensive list of corms and tubers here