Although they're often substituted for them in recipes that call for yams, sweet potatoes have absolutely nothing in common with that African and Caribbean vegetable. Sweet potatoes have a sugary-tasting orange flesh and a thin, tan-coloured skin, while yams have a rough, reddish skin and a starchy, pale orange interior. Yams are the cylindrical tubers found in Chinese and Jamaican groceries. To add to the confusion, sweet potatoes are often called yams in the southern U.S. But they're two completely different plants.
This comfort-food recipe for sweet potato salad comes from the New York Times's Best Of Craig Claiborne (Random House) and calls for the real thing. In boiling water, cook 11/2 pounds of sweet potatoes until soft; drain. Once they're cool enough to handle, peel and quarter them lengthwise, then cut into 1-inch cubes. Place these in a salad bowl, sprinkle them with the juice of 4 limes and chill in the refrigerator. Peel, core and dice two large apples and add to the sweet potatoes along with 1 cup of thinly sliced, then chopped celery and 6 ounces of coarsely chopped cashews or pecans. Add enough mayonnaise to coat the veggies and nuts. Serves 4 to 6.