The Autograph tree gets its common name (also called the Signature Tree) because of the leaves. Each leaf is fairly large, 5 to 8 inches, oval, thick and sturdy. You can scratch the leaf with a sharp object and it will remove the dark green outer layer and reveal a light green inner layer. People write messages, their name, love notes and other types of graffiti into the leaves. The messages stay as long as the leaf is attached to the tree, often months. The leaves have also been used in the past as playing cards.