Family: Fagaceae, Beech view all from this family
Description Formerly a large, deciduous tree native to eastern North America; devastated by the chestnut blight, a fungal disease, in the early 1900s; now reduced to small trees, sprouting on roots of dead trees, within its historical range. New shoots often sprout from the roots when the main stem dies, so the species has not yet become extinct. However, the stump sprouts rarely reach more than 6 meters (20 ft) in height before blight infection returns. However, there are (at least) hundreds of large (2 to 5 ft diameter) trees outside its historical range, in areas where less virulent (hypovirulent) strains of the pathogen are more common, such as the 600 to 800 large trees in northern lower Michigan.
A rapidly growing deciduous hardwood tree, it reached up to 30–45 meters (100–150 ft) tall and 3 meters (10 ft) in diameter, and ranged from Maine and southern Ontario to Mississippi, and from the Atlantic coast to the Appalachian Mountains and the Ohio Valley. There are several related chestnut species, such as the European Sweet Chestnut, Chinese Chestnut, and Japanese Chestnut, which are distinguishable only with difficulty from the American species. C. dentata can be best identified by the larger and more widely spaced saw-teeth on the edges of its leaves, as indicated by the scientific name dentata, Latin for "toothed". The leaves, which are 14–20 centimeters (5–8 in) long and 7–10 centimeters (3–4 in) broad, also tend to average slightly shorter and broader than those of the Sweet Chestnut. The blight-resistant Chinese Chestnut is now the most commonly planted chestnut species in the U.S. It can be distinguished from the American Chestnut by its hairy twig tips which are in contrast to the hairless twigs of the American Chestnut. The chestnuts are in the beech family along with beech and oak, and are not closely related to the horse-chestnut, which is in the family Sapindaceae.
The American Chestnut is a prolific bearer of nuts, usually with three nuts enclosed in each spiny green burr, and lined in tan velvet. The nuts develop through late summer, the burrs opening and falling to the ground near the first fall frost.