A tree's leaf is also one major botanical marker that helps in keying out and identifying any species of tree that has a leaf. Most trees can be identified by the leaf alone - they are unique! Tree Leaves come in many shapes and sizes, many with similar structures but most with subtle differences. Even slight differences can determine an exact tree species identification.
True leaves are blade-like and have a connection to the twig called a stalk or petiole. The edges of all leaves are called margins and can be smooth or toothed but can also be entire (without lobes) or with a lobe and a sinus.