Cassava

A woody perennial shrub, scientific name Manihot esculenta Crantz, that is extensively cultivated for its starchy root. Originally from Brazil and Paraguay, the species is now believed to be extinct in the wild.

Grown as an annual crop, the root is dried and ground into flour, which can be used similarly to wheat (and is so used by some people with allergies to other grain crops). Cassava root is also made into tapioca.

External links:

Cassava - Purdue University Horticulture