Does a bristly acorn cap enclose 1/2 or more of the acorn, with little or no stalk; the leaves broadest above the middle, shallowly to deeply lobed,often with a pair of deep SINUSES just below the middle?
CLUE: The bark on twigs is often in corky ridges.

Does a slightly fringed acorn cap enclose 1/2 or less of the acorn with the acorn on a 1"-3" stalk; the leaves shallowly LOBED or with coarse rounded teeth?
CLUE: The bark peels on young branches.

Does the acorn cap nearly enclose the acorn, with the acorn stalk 1/2"-1"long?