Throughout most of the year, it is easy to forget the presence of the trees around you. Although they provide shade and block the wind from your home, they easily blend into the landscape, becoming part of the background of your life. But when autumn arrives, trees turn into a rainbow of colors, and leaves spiral to the ground within your reach. If autumn's splendor tempts you to become better acquainted with your trees, autumn leaf identification is a place to start.
Deciduous trees lose their leaves in the autumn to protect against water loss in the winter, when the sun causes water to evaporate from the leaves but the frozen ground won't yield replenishment. Leaves turn color in response to chemical changes inside of the leaf that prepares it to fall. For the would-be tree taxonomist, autumn color provides another clue to aid in identification.
When preparing to identify a leaf, you need little besides a field guide or good online reference for trees in your area. Many local extensions and university botany departments maintain interactive websites that guide you through identifying common trees in your region. Although autumn leaves are generally portable and can be collected and identified at home, taking notes on other characteristics of the tree from which the leaf came can help you if you get stuck trying to identify the tree from the leaf alone.
One of the advantages to identifying a leaf in the autumn is that the coloration provides a vibrant and easily observable extra clue about your leaf's identify. A tree species not only always produces the same color autumn leaves, but also the color change occurs at the same time of the year. Color alone can sometimes narrow down the possible identities of your leaf considerably.
In many cases, color alone isn't enough to definitively identify a tree. Also observe the type and shape of the leaf. Simple leaves occur individually, with a bud at the base of the stem, while compound leaves include multiple leaves on a stem. Individual leaflets do not have buds at their bases. If you have a bunch of leaves on a branch, note whether they emerge opposite each other or in an alternating pattern on the branch. Finally, observe the basic shape of the leaf. Common leaf shapes include elliptic, lobed and heart-shaped.
Observing other details about the tree that your leaf came from can further simplify identification. Notice the color and texture of the bark, the size and shape of the tree and the habitat in which it grows. Consult your field guide to find a species that matches all of the information you have collected.