[4] Their mature heights vary from the smallest species of chinkapins, often shrubby,[5] to the giant of past American forests, C. dentata that could reach 60 metres (200 feet).

Two or three flowers together form a four-lobed prickly calybium, which ultimately grows completely together to make the brown hull, or husk, covering the fruits.

Genetics have indicated the California native "golden chinkapin" (Chrysolepis chrysophylla) is worthy of inclusion in a different genus along with a species from Coastal China.

[11] It has been a staple food in southern Europe, Turkey, and southwestern and eastern Asia[18][34] for millennia, largely replacing cereals where these would not grow well, if at all, in mountainous Mediterranean areas.

[32] Until the introduction of the potato, whole forest-dwelling communities which had scarce access to wheat flour relied on chestnuts as their main source of carbohydrates.

[39] In 1802, an Italian agronomist said of Tuscany that "the fruit of the chestnut tree is practically the sole subsistence of our highlanders",[40] while in 1879 it was said that it almost exclusively fed whole populations for half the year, as "a temporary but complete substitution for cereals".

[42] In France, the marron glacé, a candied chestnut involving 16 different processes in a typically French cooking style, is always served at Christmas and New Year's time.

Some slandered chestnut products in such words as the bread which "gives a sallow complexion" written in 1770,[44] or in 1841 "this kind of mortar which is called a soup".

[45] The last decades' worldwide renewal may have profited from the huge reforestation efforts started in the 1930s in the United States to establish varieties of C. sativa which may be resistant to chestnut blight, as well as to relieve the strain on cereal supplies.

[7] During British colonial rule in the mid-1700s to 1947, the sweet chestnut, C. sativa, was widely introduced in the temperate parts of the Indian subcontinent, mainly in the lower to middle Himalayas.

[50] In South Korea, roasted chestnuts (gunbam) are a popular winter snack, and serve as a symbol of abundance in ancestral rituals.

[53][54] Imported chestnuts (known as kastanyas in Tagalog, from Spanish castañas) are traditionally sold as street food in the Philippines during the Christmas season.

[58] In 1911, the food book The Grocer's Encyclopedia noted that a cannery in Holland included in its "vegetables-and-meat" ready-cooked combinations, a "chestnuts and sausages" casserole beside the more classic "beef and onions" and "green peas and veal".

This celebrated the chestnut culture that would bring whole villages out in the woods for three weeks each autumn (and keep them busy all winter), and deplored the lack of food diversity in the United States's shop shelves.

Within 40 years, the nearly four billion-strong American chestnut population in North America was devastated;[59] only a few clumps of trees remained in Michigan, Wisconsin, California, and the Pacific Northwest.

[38] Due to disease, American chestnut wood almost disappeared from the market for decades, although quantities can still be obtained as reclaimed lumber.

[60] Today, they only survive as single trees separated from any others (very rare), and as living stumps, or "stools", with only a few growing enough shoots to produce seeds shortly before dying.

Since the mid-20th century, most of the US imports are from Southern Italy, with the large, meaty, and richly flavored Sicilian chestnuts being considered among the best quality for bulk sale and supermarket retail.

[22] The Japanese chestnut (C. crenata) does well in wet and humid weather and in hot summers (about 30 °C); and was introduced to New Zealand in the early 1900s, more so in the upper North Island region.

[16] Most chestnut wood production is done by coppice systems, cut on a 12-year rotation to provide small timber which does not split as badly as large logs.

A study presented in 1997 has evaluated positively the potential increase in productivity with mixed stands and plantations, compared to plots of only one species.

[90] C. dentata seedlings in Ohio reforestation efforts are best achieved by planting them in places with little or no arboreous land cover, because of the need for light.

[38] They contain about 8% of various sugars, mainly sucrose, glucose, fructose, and in lesser amounts, stachyose and raffinose, which are fermented in the lower gut, producing gas.

In 1882 at Privas, he invented the technology to make marrons glacés on an industrial scale (although a great number of the more than 20 necessary steps from harvest to the finished product are still accomplished manually).

[100] In Spain, on 31 October on the eve of the All Saints' Day, Catalonia celebrates la castanyada, a festivity that consists of eating chestnuts, panellets, sweet potatoes and muscatell.

[106] The continental blockade following shortly after (1806–1814) increased the research into developing chestnuts as a source of sugar, but Napoleon chose beets instead.

[4] It grows so freely in Britain that it was long considered a truly native species, partly because the roof of Westminster Hall and the Parliament House of Edinburgh were mistakenly thought to be constructed of chestnut wood.

[111] The bark imparts a dark color to the tannin, and has a higher sugar content, which increases the percentage of soluble non-tans, or impurities, in the extract; so it was not employed in this use.

These properties make chestnut extract especially suitable for the tanning of heavy hides and to produce leather soles for high-quality shoes in particular.

[119] Chestnut buds have been listed as one of the 38 substances used to prepare Bach flower remedies,[120] a kind of alternative medicine promoted for its effect on health.