The burr oak is named for the burr-like appearance of the acorns, and can grow very tall and straight with stout limbs and short twigs. Acorns have little to no bitterness and are a valuable food source for deer, squirrels, and other wildlife.
Midwestern US, extending north to Canada, south to eastern Texas, and east to Pennsylvania. Spotty distribution in parts of the Southeast.
In the Midwest, burr oak can be found from ridge tops down to flat lands and is a very common oak tree. In the Southeast, it prefers to grow along streambanks and other areas near water.
Post Oak - the general appearance of the tree is similar, including the bark and the stout limbs with short twigs. However, post oak leaves have large, blocky lobes and are shiny and leathery. Burr oak leaves are more rounded, with deep sinuses near the base (petiole) and shallow to no sinuses near the apex. Post oak acorns are small and not shaggy, while burr oak acorns can reach massive sizes and have shaggy caps.
Sawtooth Oak - the only similarity is the shaggy acorn caps; the two trees look entirely different. Sawtooth acorn caps are made up of entirely shaggy scales, while burr oak acorn caps only have shaggy hairs around the outer edge of the cap.
Swamp White Oak - leaves may appear similar at a glance, but swamp white oak leaves lack the deep sinuses on the lower portion and generally have irregular shallow sinuses along the entire leaf margin. Swamp white oak acorns are also much smaller and lack the shaggy caps.
Swamp Chestnut Oak - Bark may be similar in some trees, and both species have large acorns. However, swamp chestnut oak leaves have a serrated margin that lacks the deep sinuses found in burr oak leaves. Swamp chestnut acorns do not have shaggy caps.