Sycamore and Sweet Gum
These two fairly common trees are easily identifiable by their leaf shapes. The Sycamore, Platanus occidentalis, is found almost everywhere in the deciduous forest areas of the United States. You can find them in cities, parks, and near the shores of small ponds and lakes. The Sweet Gum, Liquidambar Styraciflua, gets its name from the smell of its leaves. These leaves are star-shaped with 5 main lobes.
 

More Oaks
The last four leaves that we're going to look at are from four oak trees from around the country. The English Oak, Quercus Robur, has a small leaf that ranges from 2" to 4" with ear-like lobes. It has a very short stem. These trees got their name because colonists that settled in America during the 17th and 18th centuries brought them over from England. The Post Oak, Quercus stellata, is found on the edges of forests in the south and southeastern parts of the United States. You will usually find them in rocky or gravelly ground. It tolerates moderate shade. Notice that the three end lobes of its leaf are much larger than the other types of oak.  An interesting characteristic of the Bur Oak, Quercus macrocarpa, is that the leaf is cut nearly to the midrib in the middle of the leaf. The upper-half of this leaf is not as deeply lobed as the bottom half, as seen in the illustration. The White Oak, Quercus alba, is also found throughout the deciduous forests of the United States.
 

Want To Learn More?
If you want to learn more about how to identify North American trees by their leaves, you can read Tree Finder, A Manual for the Identification of Trees by Their Leaves written by May Theilgaard Watts. It's a mini-guide to over a hundred trees and their leaves.

Illustrations from Tree Finder by May Theilgaard Watts (c) 1963, 1991 Nature Study Guild, used by permission.