Some wish to learn to identify trees for purely recreational reasons while others want to learn to select, plant, and care for trees and understand that identification skills are critical.
It is easier to identify trees and plants in the field than collecting a leaf sample for identification at home. There are often additional clues when we examine plants in their natural environments such as milky sap, odor, or growth habit. If we do take samples to identify at a later date, it is best to collect more than just a leaf. Take leaf, twig and fruit samples (if available). When learning to identify trees, it is best to learn leaf types and patterns, but we should always use several tree characteristics such as bark, buds, fruit, flowers, twigs and leaves.
The following websites will help you learn more about identification and contain many images of trees to view, but the best way to learn how to identify trees is walking through the woods or visiting plant collections at arboretums, parks or college campuses.