Are the leaves usually deeply lobed below the middle and shallowly lobed above; with a bristly acorn cap with little or no stalk that encloses ½ or more of the acorn?
CLUE: The bark on twigs is often in corky ridges.

Are the leaves shallowly lobed or coarsely toothed; with a slightly fringed acorn cap on a 1–3" stalk that encloses ½ or less of the acorn?
CLUE: The bark peels on young twigs.