Nut trees are a type of tree that produce edible nuts. The term nut tree can refer to several different species, including the ALMOND, HAZEL, CASHEW, macadamia, ARECA, and PISTACHIO trees. Almonds are a type of nut tree that produces a small, oval-shaped nut with a hard shell. HAZEL trees produce a round nut with a thin, edible skin. Cashews are a type of nut tree that produces a kidney-shaped nut with a hard outer shell. Macadamia trees produce a round, creamy-white nut with a hard shell. ARECA trees produce a triangular-shaped nut with a hard shell. PISTACHIO trees produce a small, green nut with a soft, edible shell.