Over 100 hardwood tree species and more than 25 soft wood species are found in the state of Ohio, according to the Ohio Division of Natural Resources. These trees are a point of pride for the state, which boasts some of the finest hardwoods for commercial use. One of the easiest ways to identify these trees is through their leaves.
The state of Ohio contains over 7.9 million acres of forest, according to the Ohio State University Extension Office, equaling about 30 percent wooded land within the state. In addition to these vast tracts of forest, trees grow in yards, urban plots and alongside major roadways. Some of these trees are native, while others have become naturalized to the area and others are invasive. Some trees provide benefits to people, while others are considered harmful. Tree identification via leaves allows people to know what kind of tree they are looking at, as well as its benefits and potential downsides or dangers.
Learning to identify the trees of Ohio gives citizens and visitors a sense of the rich biological diversity of the state. Homeowners who learn to identify trees can determine what type of trees they have, as well as how to best use them to their advantage. Tree identification in Ohio serves to preserve threatened or endangered species and reduce invasive species that choke out the endemic population of trees. Those engaging in outdoor activities may also satisfy a sense of curiosity over a found leaf by identifying the tree it came from.
Trees are identified via their distinguishing characteristics. In the spring and summer months, trees are identified easily from their leaves, leaf buds and flowers. In the fall, the leaves and seeds of trees are noted. Winter identification includes looking at bud scars and leaf scars. The bark of a tree serves to identify trees year round. Using the leaves to identify the tree includes looking at the size, shape and margin, or edge of the leaf. The color of the leaf and any powders or coatings it has are also clues as to what kind of tree the leaf comes from. How the leaves are arranged on the branch is also helpful in identification.
The leaves of Ohio trees may be mistaken for the trees of another.
For example, the Ohio Buckeye, Aesculus glabra, is sometimes mistaken for the horse chestnut, Aesculus hippocastanum, due to similarities in bark and leaf type, as well as a similar looking seed. The leaves of the Ohio Buckeye are dark green, oppositely arranged and composed of palmately compound groups of five to seven leaflets of 3 to 6 inches in length. The leaves of the horse chestnut similar except for their yellow green color and the fact that the leaflets are 5 to 12 inches long. Ohio buckeyes are elliptical, and wider near the base, while horse chestnut leaves are obovate, and wider near the tip.
The wrong identification of a tree is especially dangerous when the person trying to identify the tree is doing so to harvest parts of the tree for culinary or medicinal purposes.
Local colleges and universities, as well as some local libraries, offer dendrology classes or lectures. Nature walks offered by libraries, civic associations and county extension offices are also ways to learn about tree identification and get hands-on experience working with tree identification, as well as pointing out types of trees found in your part of the state. If you come across an unknown tree and are unable to identify it, call your local cooperative or extension office, or speak to a representative from the Ohio Department of Natural Resources (ODNR) Division of Forestry.