Oak leaves are simple, pinnately veined and usually lobed. The small flowers are pollinated by the wind. The fruit (acorn) is classified as a nut. The acorns of the white oaks will ripen and germinate in one year. It takes two years for the black oak species to accomplish the same process.
The western oaks are not as valuable for lumber as the eastern varieties. The bark is high in tannin which is extracted for use in treating leather. The eastern oaks include the following kinds. The red oak is the largest, growing over 100 feet. The scarlet oak leaves turn bright red in fall. The live oak has evergreen leaves. The bur oak has large nuts which are eaten by animals. The blackjack oak leaves form a triangle. There are about 200 kinds of oak.