High Quality Content by WIKIPEDIA articles! The American Chestnut (Castanea dentata) is a large, deciduous tree of the beech family native to eastern North America. Before the species was devastated by the chestnut blight, a fungal disease, it was one of the most important forest trees throughout its range. There are now very few mature specimens of the tree within its historical range, although many small sprouts of the former live trees remain. 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.