Yam plants bear thick tubers, climbing stems, leaves, and flowers. The greater majority of yam plants are grown in warm regions of the tropics. In Africa and New Guinea, the yam is the primary agricultural commodity. In the United States, sweet potatoes outnumber yam plants and consumption. The flesh of the yam can be white, yellow, pink or purple.
Some yams are sweet, some are tasteless, and others are bitter.
Some varieties of yams grow up to 7 feet in length, and can weigh up to 150 pounds. All varieties of yams can be boiled, broiled, fried, roasted or baked. Because most varieties of yams are large in size, it is rare to find whole yams in any produce section in North America. Look for yams which are free of blemishes and bruises, and have tight, unwrinkled skins. The flesh of the yam should feel firm.