Click on the images help you identify a bur oak.
Form
Under favorable conditions, bur oaks can reach 80 feet or higher with a trunk diameter of 36 to 48 inches or more. Under unfavorable conditions, shorter in height with gnarled branches covered with corky tissue. In dense forests, the trunk is straight with short branches. In open conditions, bur oaks have broad tops of heavy spreading branches and a relatively short body.
Bark
Thick, deeply furrowed on surface with irregular platelike broken scales often slightly tinged with red. Image shows a harmless fungus that causes outer bark to slough off.
Leaf
Simple, alternate on stem. Length 6 to 12 inches. Several leaves grow from ends of twigs. Leaves have a pair of deep indentations near base and wavy notches on broad middle and upper portions. Summer color is shiny, dark green, turning yellow, brown, and rusty red in autumn.
Fruit (seed)
Acorn set deeply or almost enclosed in a fringed cup. Diameter may reach 1" or more. Size varies widely. Seed is bitter.
Range
One of the most common trees in Minnesota, bur oaks extend into the western prairies. Usually grows singly in open stands and in fields. While extremely drought tolerant, it favors moist, well-drained soil. Adapted to periodic fires, especially in savanna areas. Easily propagated but grows slowly. Moderately shade tolerant.
Wood uses
The heavy, hard, strong, tough, durable, rich brown wood is used for furniture, interior finish, flooring, structural material, and railroad ties.