What are the differences between sweet potatoes and yams?

Sweet potatoes, which are root vegetables, and yams, which are tubers, are two types of herbaceous perennial vines that come from two different plant families native to different locations. Sweet potatoes and yams differ in size, taste, texture and nutritional content.

Sweet potatoes, hailing from the Convolvulaceae family, have white or orange flesh, smooth skin and a sweet flavor. They are typically short and blocky in shape. Sweet potatoes are rich in Vitamins A and C and beta carotene, while yams contain a smaller amount of Vitamin C and more potassium. Yams, from the Dioscoreaceae family, have purple, red or white flesh and a starchy flavor. They have rough, scaly skin and can grow up to 5 feet in length, depending on the variety.