Editing Chestnut (section)

== Description ==
[[Image:Sweet chestnut DSCF0160.JPG|thumb|Bark of ''[[Castanea sativa|C. sativa]]'' (sweet chestnut)]]

Chestnut trees are of moderate growth rate (for the Chinese chestnut tree) to fast-growing for American and European species.<ref name="botanical" /> Their mature heights vary from the smallest species of chinkapins, often shrubby,<ref name="uniminnesota">[http://www.extension.umn.edu/yardandgarden/ygbriefs/h401chestnuts.html ''Chestnuts, Horse-Chestnuts, and Ohio Buckeyes''] {{webarchive|url=https://web.archive.org/web/20080916230008/http://www.extension.umn.edu/yardandgarden/ygbriefs/h401chestnuts.html|date=September 16, 2008}}. In Yard and Garden Brief, Horticulture department at University of Minnesota.</ref> to the giant of past American forests, ''[[American chestnut|C. dentata]]'' that could reach {{Convert|30|m|abbr=off}}.<ref>{{cite journal |last1=Collins |first1=Rachel J. |last2=Copenheaver |first2=Carolyn A. |last3=Kester |first3=Mary E. |last4=Barker |first4=Ethan J. |last5=DeBose |first5=Kyrille Goldbeck |title=American Chestnut: Re-Examining the Historical Attributes of a Lost Tree |journal=Journal of Forestry |date=2017 |doi=10.5849/JOF-2016-014}}</ref> Between these extremes are found the Japanese chestnut (''[[Castanea crenata|C. crenata]]'') at {{nowrap|10 m}} average;{{NoteTag|Some specimens can have greater bulk.<ref name="APS1">[http://www.apsnet.org/online/feature/chestnut/images/figure4.htm American Phytopathological Society] {{webarchive |url=https://web.archive.org/web/20080509091414/http://www.apsnet.org/online/feature/chestnut/images/figure4.htm |date=May 9, 2008 }}</ref>}} followed by the Chinese chestnut (''[[Castanea mollissima|C. mollissima]]'') at about {{nowrap|15 m}}, then the European chestnut (''[[Castanea sativa|C.&nbsp;sativa]]'') around {{nowrap|30 m}}.<ref name="nzcouncil">[http://www.nzcc.org.nz/factsheet.html Chestnuts worldwide and in New Zealand] {{Webarchive|url=https://web.archive.org/web/20080705110047/http://www.nzcc.org.nz/factsheet.html|date=2008-07-05}}. By the New Zealand Chestnut Council, 2000.</ref>

The Chinese and more so the Japanese chestnuts are both often multileadered and wide-spreading,<ref name="nzcouncil" /> whereas European and especially American species tend to grow very erect when planted among others, with little tapering of their [[columnar]] [[Trunk (botany)|trunks]], which are firmly set and massive. When standing on their own, they spread on the sides and develop broad, rounded, dense [[Crown (botany)|crowns]] at maturity.<ref name="botanical" /> The [[leaf|foliage]] of the European and American species has striking yellow autumn coloring.<ref name="harvard">[http://harvardforest.fas.harvard.edu/research/leaves/future.html Autumn Foliage Color:Past, Present, and Future.] {{webarchive|url=https://web.archive.org/web/20080513180502/http://harvardforest.fas.harvard.edu/research/leaves/future.html|date=May 13, 2008}} Harvard University.</ref>

Its bark is smooth when young,<ref name="chattooga">[http://www.chattoogariver.org/index.php?req=chestnut&quart=W2002 The American Chestnut Tree]. By Samuel B. Detwiler. Reprinted from American Forestry, October, 1915. Chattooga Conservancy.</ref> of a vinous [[Maroon (color)|maroon]] or red-brown color for the American chestnut,<ref name="2020site" /> grey for the European chestnut. With age, American species' bark becomes grey and darker, thick, and deeply [[furrow]]ed; the furrows run longitudinally, and tend to twist around the trunk as the tree ages, sometimes reminiscent of a large cable with twisted strands.<ref name="botanical" />

[[File:Chestnut flowers.jpg|thumb|''C. sativa'' male [[catkin]]s (pale buff) and female catkins (green, spiny, partly hidden by leaves)]]

The leaves are simple, [[Glossary of leaf morphology#ovate|ovate]] or [[lanceolate]], {{nowrap|10–30 cm|abbr=on}} long and {{nowrap|4–10 cm|abbr=on}} wide, with sharply pointed, widely spaced teeth, with shallow rounded [[Leaf#Margins (edge)|sinuates]] between.<ref name="answers">[http://www.answers.com/topic/chestnut Chestnut] in Answers.com.</ref>

The [[flower]]s follow the leaves, appearing in late spring or early summer<ref name="botanical" /> or into July.<ref name="uniminnesota" /> They are arranged in long [[catkin]]s of two kinds,<ref name="uniminnesota" /> with both kinds being borne on every tree.<ref name="2020site" /> Some catkins are made of only male flowers, which mature first. Each flower has eight [[stamen]]s, or 10 to 12 for ''C. mollissima''.<ref name="tai">{{cite web |title=電子書 台灣植物誌第二版 Flora of Taiwan, 2nd edition 2: 53 - Plants of Taiwan 台灣植物資訊整合查詢系統 |url=http://tai2.ntu.edu.tw/udth/bin/fot1.exe/browse?bid=2&page=53 |url-status=dead |archive-url=https://web.archive.org/web/20090720225715/http://tai2.ntu.edu.tw/udth/bin/fot1.exe/browse?bid=2&page=53 |archive-date=2009-07-20 |access-date=2008-08-11 |website=ntu.edu.tw}}</ref> The ripe [[pollen]] carries a heavy, sweet odor<ref name="uniminnesota" /> that some people find too sweet or unpleasant. Other catkins have these pollen-bearing flowers, but also carry near the [[twig]] from which these spring, small clusters of female or fruit-producing flowers. 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.<ref name="botanical" />

Chestnut flowers are not self-compatible, so two trees are required for [[pollination]]. All ''Castanea'' species readily hybridize with each other.

=== Fruit ===
The fruit is contained in a spiny (very sharp) [[Calybium and cupule|cupule]] {{nowrap|5–11 cm}} in diameter, also called "bur" or "[[burr (fruit)|burr]]".<ref name="cnr">[http://www.cnr.vt.edu/DENDRO/DENDROLOGY/syllabus/factsheet.cfm?ID=23 Chinese Chestnut] {{webarchive|url=https://web.archive.org/web/20081014174650/http://www.cnr.vt.edu/DENDRO/DENDROLOGY/syllabus/factsheet.cfm?ID=23|date=October 14, 2008}}, College of Natural Resources, Department of Forestry, VirginiaTech.</ref> The burrs are often paired or clustered on the branch<ref name="uniminnesota" /> and contain one to seven nuts according to the different [[species]], [[variety (botany)|varieties]], and [[cultivar]]s.<ref name="foc" /><ref name="fna" /><ref name="rushforth">''Trees of Britain and Europe''. By K. Rushforth. Collins. 1999. {{ISBN|0-00-220013-9}}.</ref><ref name="bean1">''Trees and Shrubs Hardy in the British Isles''. By W.J. Bean. 8th ed., vol. 1. John Murray. 1976. {{ISBN|0-7195-1790-7}}.</ref> Around the time the fruits reach maturity, the burrs turn yellow-brown and split open in two or four sections. They can remain on the tree longer than they hold the fruit, but more often achieve complete opening and release the fruits only after having fallen on the ground; opening is partly due to soil [[humidity]].<ref name="fao" />

The chestnut fruit has a pointed end with a small tuft at its tip (called "flame" in [[Italian language|Italian]]),<ref name="fao" /> and at the other end, a [[:wikt:hilum|hilum]] – a pale brown attachment scar. In many varieties, the fruit is flattened on one or two sides. It has two skins. The first one is a hard, shiny, brown outer hull or [[husk]], called the pericarpus;<ref name="laren43">[http://www.chestnutsaustralia.com.au/content/view/18/43/ ''Chestnut Know-How''] {{webarchive|url=https://web.archive.org/web/20080719000141/http://www.chestnutsaustralia.com.au/content/view/18/43/|date=2008-07-19}}. By David McLaren. Written for Chestnut Australia Inc. 1999.</ref> the industry calls this the "peel".<ref name="fao" /> Underneath the pericarpus is another, thinner skin, called the pellicle or episperm.<ref name="laren43" /> The pellicle closely adheres to the [[seed]] itself, following the grooves usually present at the surface of the fruit. These grooves are of variable sizes and depths according to the species and variety.

The fruit inside these shows a germ with two [[cotyledon]]s connected to creamy-white flesh throughout.<ref name="chestnutbrook">[https://web.archive.org/web/20120320094600/http://www.chestnutbrook.com.au/what-are-chestnuts.html ''What Are Chestnuts'']. Information page by a small Australian grower in [[Balingup, Western Australia]].</ref> Some varieties have consistently only one embryo per fruit (nut) or have only one large fruit per burr, well rounded (no flat face). The name of varieties with these characteristics may start with "marron"<ref name="fao" /> for example ''marron de Lyon'' in France, or ''Marrone di Mugello'' in Italy.

Chestnut fruit may not exhibit [[epigeal]] dormancy.  It may germinate right upon falling to the ground in the autumn, with the roots emerging from the seed right away and the leaves and stem the following spring. The germ can lose viability soon after ripening and under drying conditions.

The superior fruiting varieties among European chestnuts have good size, sweet taste, and easy-to-remove inner skins.<ref>{{Cite web |last=Gibson |first=Roger and Jean |title=New Zealand Chestnut Council - fact sheet |url=http://www.nzcc.org.nz/factsheet.html |url-status=dead |archive-url=https://web.archive.org/web/20180123120437/http://nzcc.org.nz/factsheet.html |archive-date=2018-01-23 |access-date=2018-01-10 |website=www.nzcc.org.nz}}</ref><ref>{{Cite book |last=Pareek |first=O.P. |title=Systematic Pomology |publisher=Scientific Publishers |year=2017 |page=428}}</ref> American chestnuts are usually very small (around {{nowrap|5 g}}), but sweet-tasting with easy-to-remove pellicles. Some Japanese varieties have very large nuts (around {{nowrap|40 g}}), with typically difficult-to-remove pellicles. Chinese chestnut pellicles are usually easy to remove, and their sizes vary greatly according to the varieties, although usually smaller than the Japanese chestnut.<ref name="nzcouncil" />

=== Similar species ===
The unrelated [[horse chestnut]]s (genus ''[[Aesculus]]'') are not true chestnuts, but are named for producing nuts of similar appearance that are mildly poisonous to humans. True chestnuts should also not be confused with [[Eleocharis dulcis|water chestnut]]s, which are tubers of an aquatic herbaceous plant in the sedge family [[Cyperaceae]].<ref name="answers" /><ref name="chestnutbrook" /> Other species commonly mistaken for chestnut trees are the chestnut oak (''[[Quercus prinus]]'') and the American beech (''[[Fagus grandifolia]]''),<ref name="chestnuttree">[http://www.chestnuttree.net/ Chestnut Tree] {{webarchive|url=https://web.archive.org/web/20080705113403/http://www.chestnuttree.net/|date=July 5, 2008}} in chestnuttree.net.</ref><ref name="nzcouncil" /> both of which are also in the Fagaceae family. [[Brazil nuts]], called "Brasil chestnuts" (''castañas de Brasil'' in Spanish) or "chestnuts from Pará" (''castanha-do-Pará'' in Portuguese) are also unrelated.