Identify trees by observing their bark, branches, seeds and leaves. Leaf identification can be one of the quickest ways to determine what type of tree you are looking at. There are three main types of oak trees: red oak, white oak and black oak. While their leaves are all slightly different, they are still similar enough that you will know they are all from an oak tree. Using a leaf identification key is the easiest way to label an oak leaf.
Pick up the leaf from the ground so you are better able to observe its characteristics. Determine if the leaf has fallen from a tree in the immediate area. Observe the stem characteristics of the tree the leaf fell from.
Observe the leaf branching on the tree. Oak trees have alternate branching. This means that each leaf grows from a separate location on the leaf stem in an alternating pattern.
Determine what type of leaf you are holding. There are two kinds: compound leaves and simple leaves. An oak tree has simple leaves. This means there is only one large leaf for each leaf stem. Compound leaves have many smaller leaves on each stem.
Look at the leaf edges. A leaf's edge will either be lobed or not lobed. An oak leaf's edge is lobed. This means there are large indentations in the leaf, which gives its edges a curvy appearance.
Rub your finger lightly along the lobe of your leaf. If the end of the lobe is pointed, the leaf is from a red oak. A leaf with a rounded end is from a white oak. A black oak leaf will also have pointed lobes. The difference between the black oak and the red oak leaves is the width of the lobes. A black leaf's lobes are narrower than a red oak's.