E-Mail IMAGE: The edible yam tuber has a starchy, white flesh. Yams are a great source of fiber and potassium. view more Credit: S. Yamanaka Yams are a staple food in West Africa, which produces over 90% of the world's yams each year. Yams play a key role in the food security, economic income, and traditional culture for the region. While they are commonly assumed to be the same as sweet potatoes in the U.S., yams are a completely different plant. The yam tubers are much starchier and drier compared to sweet potatoes. Yams are native to Africa and Asia, and most Americans have never had a true yam.