Yam

Yams are high in Vitamin C, dietary fiber, Vitamin B6, potassium, and manganese; while being low in saturated fat and sodium,high in potassium and low in sodium, protect against osteoporosis and heart disease, provide a more sustained form of energy, and give better protection against obesity and diabetes^[8].

Yams are a primary agricultural commodity in West Africa and New Guinea.

read more at http://en.wikipedia.org/wiki/Yam_(vegetable)