It wasn't until 1876 that this fast-growing legume-family plant was introduced to the United States, where it's used primarily as pasturage and for erosion control. Kudzu, however, has been a popular food in Japan and China for thousands of years. Most of the plant can be eaten — the tender leaves and stems can be cooked as with other greens. However, it's the tuberous roots (which have been known to weigh up to 450 pounds and reach 7 feet in length) that offer this plant's real premium. These roots are dehydrated and pulverized, and it is this starchy kudzu powder that is used culinarily in myriad ways — from thickening soups and sauces to dredging foods to be deep-fried. Kudzu powder can be found in Asian markets and some health-food stores. It's high in fiber, protein and vitamins A and D.