Bur oak is a large, Deciduous tree (Having leaves that all fall off at the end of the growing season, or at least wither up and become lifeless.) with a very wide, open crown. Usually wider than tall, the tree can exceed 100 ft. in height and width. The massive trunk supports heavy, horizontal limbs and rough, deep-ridged bark. Leaves up to 9 inches long with a central midrib from which branch veins lead into rounded lobes. Lobes separated by deep sinuses reaching, in some cases, to within 1/2 inch of the midrib. Lobes beyond the midpoint of the blade wavy margined and longer and broader than those toward the base. Acorns large, up to 1 1/2 inches broad.