The leaves are from 10 to 25 cm (4 to 10 in) in length and about the same width.īlackjack oak stump, approx. īlackjack oaks in the Cross Timbers can grow from 15 to 18 m (50 to 60 ft) high but seldom reach more than 12 m (40 ft), with a trunk diameter of 41 cm (16 in). The acorn is small, 12–20 millimeters ( 1⁄ 2– 3⁄ 4 in) long and 10–18 mm ( 3⁄ 8– 3⁄ 4 in) broad like those of other red oaks, it takes 18 months to mature. They are dark green and glossy above, pubescent underneath, and often remain attached to the twigs through the winter after turning colors from red to brown in the fall. The leaves are 7–20 centimeters (3–8 inches) long and broad, and typically flare from a tapered base to a broad three-lobed bell shape with only shallow indentations. Quercus marilandica is a small deciduous tree growing to 15 meters (49 feet) tall, with bark cracked into rectangular black plates with narrow orange fissures. It is native to the eastern and central United States. Quercus marilandica, the blackjack oak, is a small oak, one of the red oak group Quercus sect. Generalized natural range of Quercus marilandica