Pin oak, a tree that can reach 30m in height, is a monoecious tree. Its male catkins are hairy and 5-10cm, female flowers have wooly hairs and red stigmas. Its acorns are 1-2.5cm wide. The acorn cap is saucer-shaped with very small scales that are covered with tiny hairs, it covers 1/4-1/3 of the nut, which is 10-14mm wide. Its leaves are shiny, paler on the underside, often taper to a point at the base, wrap around the petiole slightly, with 2-3 pairs of toothed lobes, each lobe much longer than the center part of the leaf is wide. Its lower branches are slender, widely spreading, and bend slightly downward. Its bark is smooth with shallow furrows and flat ridges. Mature twigs are smooth. Winter buds are smooth and taper to a point with straight sides.
Its leaves appear similar to northern pin oak and scarlet oak, but pin oak can be distinguished from these species by its shallower acorn cap, covering only about 1/4 of the nut. Also, it is found in wet lowlands as oppose to well-drained uplands.
