Juglans regia L.
Also known as Persian and English walnut, the common walnut is the fruit of the walnut tree, ubiquitous in Southeast Asia, the Far East and the Americas. The hard shell stores a nut high in omega-3 polyunsaturated fat − which gives it a high nutritional content, but also favors rancidity. If kept in a cool, dark environment, it retains the flavor and is a good addition to savory and sweet dishes. It can be used in stews, farofas (seasoned manioc flour), salads, rice, in fillings for fresh pasta, sauces, breads, cakes, pies, ice creams, custards, trifles, and puddings. Candied walnuts give a crunchy touch to salads and desserts. They may also be eaten on their own. Walnuts are sold in Brazil both whole and shelled.