any of several species of North American timber trees, with chestnutlike leaves, belonging to the white oak group of the genus Quercus in the beech family (Fagaceae). Specifically, chestnut oak refers to Q. prinus (or Q. montana), also called rock chestnut oak, a tree found on rocky soils of the eastern United States and southern Canada. It is usually about 21 m (70 feet) tall but may grow to 30 m. It has blackish, tannin-rich bark, with deep longitudinal ridges; the chestnutlike, lance-shaped leaves, about 18 cm (7 inches) long, have 10 to 15 pairs of parallel veins, each ending at a rounded tooth. Yellow-green above, paler and fuzzy beneath, the leaves turn orange-red or rust brown in autumn.
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