The United States (mainly California) is the world's leading producer of the English walnut (also called Persian walnut). It's grown in several other countries including China, France, India, Iran, Turkey and Yugoslavia. The English walnut has a wrinkled, tan-colored shell that encloses two large, double-lobed halves. Its sweet flavor makes it a delicious choice for out-of-hand eating, as well as a popular addition for all manner of foods sweet and savory. English walnuts are used to produce walnut oil; they also come in candied and pickled forms. They're available prepackaged or in bulk. English walnuts are a potent source of Omega-3 oils (see fats and oils). See also nuts; walnut.