(Quercus robusta)
Quercus robusta (also called robust oak) is a rare North American species of trees in the beech vamily. It has been found only in the Chisos Mountains inside Big Bend National Park in western Texas. Quercus robusta is a deciduous tree up to 13 meters (43 feet) tall. Bark is black or brown, twigs dark reddish brown. Leaves are up to 12 cm (4.8 inches) long, with a few teeth or small lobes along the edges. The tree grows in moist, wooded canyons.