Other species are native to other parts of Asia, Europe, North America, and northern Africa. Maples are easy to recognize because their leaves grow in pairs on opposite sides of the branch, and each leaf has several lobes. No other North American tree has opposite, lobed leaves. Nearly all maples lose their leaves in the autumn. In numerous species of maples, the leaves turn bright orange, red, or yellow before they drop off.
Maples flower in the spring, either before or at the same time the leaves appear.
Most maples bear male and female flowers on the same tree. Maple seeds, sometimes called keys, grow in pairs and have flat, thin wings that make them whirl and float in the wind as they fall. Breezes can carry the seeds far from the parent tree, thus helping maples spread to new areas. Maples are an important source of lumber. Some species have very hard, strong wood.