(n): a complex carbohydrate found chiefly in seeds, fruits, tubers, roots and stem pith of plants, notably in corn, potatoes, wheat, and rice; an important foodstuff and used otherwise especially in adhesives and as fillers and stiffeners for paper and textiles
(n): cassava root eaten as a staple food after drying and leaching; source of tapioca
(n): (botany) the usually underground organ that lacks buds or leaves or nodes; absorbs water and mineral salts; usually it anchors the plant to the ground
(n): any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch
(n): a low woody perennial plant usually having several major stems
Leaves are tasty too. Take the top ones from the growing tip or they can be quite bitter.