Although there are many different types of oak trees, you can normally identify an oak tree by its leaf structure that has five or six lobes:
Sometimes a keeper here in Windsor Forest,
Doth all the winter-time, at still midnight,
Walk round about an oak, with great ragg'd horns;
And there he blasts the tree, and takes the cattle,
And makes milch-kine yield blood, and shakes a chain
In a most hideous and dreadful manner.
You have heard of such a spirit, and well you know
The superstitious idle-headed eld
Receiv'd, and did deliver to our age,
This tale of Herne the Hunter for a truth.
William Shakespeare, The Merry Wives of Windsor