The apple tree is a deciduous tree in the rose family best known for its sweet, pomaceous fruit, the apple. It is cultivated worldwide as a fruit tree, and is the most widely grown species in the genus Malus. 1.More than 2,500 varieties of apples are grown in the United States, but only the crabapple is native to North America. 2.Apples contain no fat, sodium or cholesterol and are a good source of fiber. 3.Apple trees take four to five years to produce their first fruit. 4.Apples ripen six to 10 times faster at room temperature than if they are refrigerated.