Macadamia Nut, an oily, edible nut produced by several species of evergreen shrubs and trees. (Botanically, it is not actually a nut but the kernel of a fruit called a drupe.) The nut is spherical, with a diameter of 1/2 to 1 1/2 inches (13 to 38 mm), and is protected by a very tough shell. It has a sweet, buttery flavor and is usually eaten raw, roasted, or fried. The smooth-shelled macadamia nut, also called the Queensland, or Australian, nut, is produced by a tree that bears small white flowers and reaches a height of 60 feet (18 m). The tree producing the rough-shelled macadamia nut bears small pink flowers and grows to a height of 50 feet (15 m). Both species are grown commercially in Hawaii, California, and Australia.
The trees bearing macadamia nuts belong to the family Proteaceae. The tree of the smooth-shelled macadamia nut is Macadamia integrifolia; of the rough-shelled macadamia nut, M. tetraphylla.The macadamia nut has a hard, smooth shell with a white kernel.