The American chestnut (C. dentata), a fast-growing tree that often reached 30 metres (100 feet), formerly extended over a large area of eastern North America from which it has been virtually eliminated by chestnut blight, a fungal disease. Vigorous stump sprouts are found in many areas, but most harbour the fungus, and repeated attacks deter the cultivation of the species for its timber or nuts. Crosses of the remaining trees with resistant Asian species have produced a few blight-resistant hybrids, now being developed to replace the American chestnut.
The other North American member of the genus, the American chinquapin, also known as dwarf chestnut (C. pumila), is found throughout much of the eastern and southern United States. It ranges in size from a small shrub to a tree up to 14 metres (46 feet) high. It is also susceptible to chestnut blight, but some varieties have proven to be more resistant than the American chestnM
The European chestnut (C. sativa), 30 metres (100 feet) tall, is native to Eurasia and northern Africa; it is often called sweet, Spanish, or Eurasian chestnut. The Chinese chestnut (C. mollissima), usually less than 18 metres (about 60 feet) tall, grows at altitudes up to 2,440 metres (8,000 feet). The Japanese chestnut (C. crenata), a similar shrub or tree that may grow to 9 metres (30 feet) or more, is found at elevations of less than 915 metres (3,000 feet); it has heart-shaped leaves about 17 cm (7 inches) long. The nuts of the European, Chinese, and Japanese chestnuts have local importance as food and are exported in large quantities. Small nuts of the European chestnut are used as feed for livestock or are milled into flour; choice nuts, called marrons, come from varieties developed to produce one large nut in the bur. Varieties of all three trees are cultivated as ornamentals in Europe, North America, and Asia. The European chestnut produces useful timber as well.