Glossary: yam

This thick, tropical-vine tuber is popular in South and Central America, the West Indies and parts of Asia and Africa. Although sweet potatoes and yams are similar in many ways and therefore often confused with one another, they are from different plant species. In the southern United States, sweet potatoes are often called yams and to add to the confusion, canned sweet potatoes are frequently labeled yams. True yams, however, are not widely marketed and are seldom grown in the United States. Though they can be similar in size and shape to sweet potatoes, yams contain more natural sugar and have a higher moisture content. On the downside, they're not as rich in vitamins A and C as sweet potatoes. There are over 150 species of yam grown throughout the world. They can range in size from that of a small potato to behemoths over 71a

From THE NEW FOOD LOVERS COMPANION, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.