Also called corn smut, maize mushroom and huitlacoche, this gourmet rage is actually a bulbous fungus (technically known as Ustilago maydis) that attacks ears of corn and makes the kernels swell to 10 times their normal size. The corn's color turns an ugly medium- to dark-gray verging on black. Although most U. S. farmers consider it a plague and destroy infected ears, the Aztecs are said to have prized cuitlacoche (in Nahuatl cuitlatl means "excrement," cochi means "black"). Enthusiasts say that cuitlacoche has a smoky-sweet flavor that's a cross between that of corn and mushroom. Cuitlacoche is currently being cultivated in limited quantities in California, Florida, Georgia and Virginia. It's sold canned and frozen in some gourmet markets. It can occasionally be found in specialty produce and farmer's markets (during corn season) and can also be purchased by mail order. Cuitlacoche is used in a variety of dishes including sautés, soups, casseroles — in general, any preparation where cooked mushrooms would be appropriate.