Bur oak (Quercus macrocarpa)

Bur oak photograph; MN DNR, Ellen Fuge

Form

Height 80' or more under favorable conditions with a diameter of 36" to 48" or more; under unfavorable conditions not over 15' in height with gnarled branches covered with corky tissues; in dense forests trunk is straight with short branches; however, tree usually has a broad top 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.

Bur oak photograph; MN DNR

Leaf

Simple, alternate on stem, length 6" to 12"; crowded at ends of twigs; has pair of deep indentations near base and wavy notches on broad middle and upper portions; shiny, dark green turning yellow or brown in autumn.

Fruit (seed)

Acorn set deeply or almost enclosed in a fringed cup; diameter may reach 1" or more, however, it varies widely in respect to size and the degree to which the nut is enclosed in the mossy fringed cup; seed is bitter.

Range

One of the most common trees in Minnesota, extending far out on the prairies in the western part of the state; usually grows singly in open stands and in fields; requires moist, well-drained soil; easily propagated but grows slowly; moderately shade tolerant.