Root vegetables are plant roots used as vegetables. Here "root" means any underground part of a plant.
Root vegetables are generally storage organs, enlarged to store energy in the form of carbohydrates. They differ in the concentration and the balance between sugars, starches, and other types of carbohydrate. Of particular economic importance are those with a high carbohydrate concentration in the form of starch. Starchy root vegetables are important staple foods, particularly in tropical regions, overshadowing cereals throughout much of West Africa, Central Africa, and Oceania, where they are used directly or mashed to make fufu or poi.
Botany distinguishes true roots such as tuberous roots and taproots from non-roots such as tubers, rhizomes, corms, and bulbs, though some contain both taproot and hypocotyl tissue, making it difficult to tell some types apart. In ordinary, agricultural, and culinary use, "root vegetable" can apply to all these types.