Quercus macrocarpa, the bur oak, sometimes spelled burr oak, is a species of oak in the white oak section Quercus sect. Quercus, native to North America. This plant is also called mossycup oak and mossycup white oak.
Quercus macrocarpa is a medium to large sized deciduous oak of the white oak group that typically grows 60-80’ (less frequently to 150’) tall with a broad-spreading, rounded crown. Acorn cups are covered with a mossy scale or bur near the rim, hence the common names. It is native to a variety of habitats in central and eastern North America. Insignificant monoecious yellowish-green flowers in separate male and female catkins appear in spring as the leaves emerge. Fruits are oval acorns (to 1 1/2” long), with fringed, burry cups that extend to approximately 1/2 to 3/4 the acorn length. Acorns are an important source of food for wildlife. Leathery, dark green leaves (6-12” long) with 5-9 rounded lobes are variable in shape, but usually have a pair of deep central sinuses that extend nearly to the midrib giving the leaf a waisted appearance. Fall color is an undistinguished yellow-brown.