Yuca

Yuca is also called Cassava, manioc,  balinghoy, mogo, mandioca, kamoteng kahoy, tapioca-root(predominantly in India) and manioc root. It is a woody shrub of the Euphorbiaceae (spurge) family native to South America. It is a good source of carbohydrates, but a poor source of protein. A diet consisting predominantly of cassava root can cause protein-energy malnutrition.

The cassava root is long and tapered, with a firm, homogeneous flesh encased in a detachable rind, about 1mm thick, rough and brown on the outside. Commercial varieties can be 5 to 10 cm in diameter at the top, and around 15 cm to 30 cm long. A woody cordon runs along the root’s axis. The flesh can be chalk-white or yellowish. Cassava roots are very rich in starch and contain significant amounts of calcium (50 mg/100g), phosphorus (40 mg/100g) and vitamin C (25 mg/100g). However, they are poor in protein and other nutrients.
(Info from http://en.wikipedia.org/wiki/Cassava)