Yam, for one, is a type of TUBER and ROOT vegetable. It is a starchy, edible ROOT that is widely cultivated in tropical and subtropical regions around the world. Yams are typically long and cylindrical in shape, and can range in size from that of a small potato to over two meters in length. They have a rough, scaly skin and white, yellow, or purple flesh. Yams are a good source of dietary fiber, vitamins, and minerals, and are often used in dishes such as soups, stews, and curries.