Quercus velutina, the eastern black oak or more commonly known as simply black oak, is an oak in the red oak (Quercus sect. Lobatae) group of oaks. It is native to eastern North America from southern Ontario south to northern Florida and southern Maine west to northeastern Texas. It is a common tree in the Indiana Dunes and other sandy dunal ecosystems along the southern shores of Lake Michigan and to our area of northern Harford and Baltimore Counties in Maryland. Quercus velutina was previously known as yellow oak due to the yellow pigment in its inner bark, however nowadays this name is usually reserved for Chinkapin oak. It is a close relative of the western black oak (Quercus kelloggii) found in western North America.
In the northern part of its range, black oak is a relatively small tree, reaching a height of 20–25 m (65–80 ft) and a diameter of 90 cm (35 in), but it grows larger in the south and center of its range, where heights of up to 42 m (140 ft) are known. Black oak is well known to readily hybridize with other members of the red oak group of oaks being one parent in at least a dozen different named hybrids.
The leaves of the black oak are alternately arranged on the twig and are 10–20 cm (4–8 in) long with 5-7 bristle tipped lobes separated by deep U-shaped notches. The upper surface of the leaf is a shiny deep green, the lower is yellowish-brown. There are also stellate hairs on the underside of the leaf that grow in clumps.