Editing Acorn

{{short description|Nut of the oak tree}}
{{about|the nut|the squash|Acorn squash|other uses|Acorn (disambiguation)}}
{{Use dmy dates|date=October 2021}}
[[File:Quercus robur acorn - Keila.jpg|thumb|[[English oak]] acorn]]
[[File:Acorns small to large.jpg|thumb|Acorns of the willow oak in [[South Carolina]] (from small to large, counterclockwise from center): ''[[Quercus phellos|Q.&nbsp;phellos]]'' (willow oak), ''[[Quercus falcata|Q.&nbsp;falcata]]'' (southern red oak; top right), ''[[Quercus alba|Q.&nbsp;alba]]'' (white oak), and ''[[Quercus coccinea|Q.&nbsp;coccinea]]'' (scarlet oak). Scale bar at upper right is 1&nbsp;cm.]]

[[File:Acorn diagram.jpg|thumb|Diagram of the anatomy of an acorn: A.) [[Calybium and cupule|Cupule]] B.) [[Pericarp]] (fruit wall) C.) Seed coat ([[Testa (botany)|testa]]) D.) [[Cotyledons]] (2) E.) [[Plumule]] F.) [[Radicle]] G.) Remains of [[Gynoecium|style]]. Together D., E., and F. make up the embryo.]]

The '''acorn''' is the [[nut (fruit)|nut]] of the [[oak]]s and their close relatives (genera ''[[Quercus]]'', ''[[Notholithocarpus]]'' and ''[[Lithocarpus]]'', in the family [[Fagaceae]]). It usually contains a [[seedling]] surrounded by two [[cotyledon]]s (seedling leaves), enclosed in a tough [[Nutshell|shell]] known as the pericarp, and borne in a cup-shaped [[Calybium|cupule]].<ref>{{cite book |url=https://books.google.com/books?id=WYPfQo9lUzoC&pg=PA32 |page=32 |year=2009 |title=Hands-On Chemical Ecology:: Simple Field and Laboratory Exercises |author=Dietland Müller-Schwarze |publisher=Springer Science & Business Media|isbn=978-1-4419-0378-5 }}</ref><ref>{{Cite encyclopedia |title=Acorn {{!}} Definition & Facts |author= |encyclopedia=Encyclopedia Britannica |date= |access-date=28 April 2024 |url= https://www.britannica.com/science/acorn-nut}}</ref> Acorns are {{convert|1–6|cm|in|frac=2|abbr=on}} long and {{convert|0.8–4|cm|in|frac=8|abbr=on}} on the fat side. Acorns take between 5 and 24 months (depending on the species) to mature; see the [[List of Quercus species|list of ''Quercus'' species]] for details of oak classification, in which acorn [[morphology (biology)|morphology]] and [[phenology]] are important factors.

==Etymology==
The word ''acorn'' (earlier ''akerne'', and ''acharn'') is related to the [[gothic language|Gothic]] name ''akran'', which had the sense of "fruit of the unenclosed land".<ref>{{OEtymD|acorn}}</ref> The word was applied to the most important forest produce, that of the oak. [[Geoffrey Chaucer|Chaucer]] spoke of "achornes of okes" in the 14th century. By degrees, popular [[etymology]] connected the word both with "corn" and "oak-horn", and the spelling changed accordingly.<ref>{{EB1911|inline=1|wstitle=Acorn|volume=1|pages=152–153}} This cites the ''New English Dictionary'', now the ''[[Oxford English Dictionary]]''</ref> The current spelling (emerged {{Circa|15th–16th}} century) derives from association with ''ac'' (Old English: "oak") + ''corn''.<ref>{{Cite web |title=Online Etymology Dictionary |url=http://www.etymonline.com/index.php?allowed_in_frame=0&search=acorn&searchmode=none |access-date=15 April 2017 |website=etymonline.com |language=en}}</ref>

==Ecology==

[[File:Ponies eating acorns on Parkhill Lawn, New Forest - geograph.org.uk - 251840.jpg|thumb|[[Ponies]] eating acorns.  Acorns can cause painful death in [[equines]], especially if eaten in excess.]]

[[File:Quercus robur - sprouting acorn.jpg|thumb|Sprouting acorn of ''[[Quercus robur]]'']]

Acorns play an important role in [[forest ecology]] when oaks are plentiful or dominant in the landscape.<ref name="USDA">{{Cite book |url=http://www.fs.fed.us/psw/publications/documents/psw_gtr044/psw_gtr044.pdf |title=Proceedings of the symposium on the ecology, management, and utilization of California oaks, June 26–28 |publisher=USDA Forest Service General Technical Report PSW-044 |year=1980 |editor-last=Plumb, Timothy R. |pages=1 to 368 |asin=B000PMY1P8}}</ref> The volume of the acorn crop may vary widely, creating great abundance or great stress on the many animals dependent on acorns and the predators of those animals.<ref name="NYT">{{Cite news |last=King, Richie S. |date=2 December 2011 |title=After Lean Acorn Crop in Northeast, Even People May Feel the Effects |work=The New York Times |url=https://www.nytimes.com/2011/12/03/nyregion/boom-and-bust-in-acorns-will-affect-many-creatures-including-humans.html |access-date=4 December 2011 |quote=there is nothing unusual about large fluctuations in the annual number of acorns.}}</ref> Acorns, along with other nuts, are termed [[mast (botany)|mast]].

Wildlife that consume acorns as an important part of their diets include birds, such as [[jay]]s, [[pigeon]]s, some [[duck]]s, and several species of [[woodpecker]]s. Small [[mammal]]s that feed on acorns include [[mouse|mice]], [[squirrel]]s and several other [[rodent]]s. One beetle species, ''[[Thorectes lusitanicus]]'', also feeds on acorns.<ref>{{Cite journal |last1=PéRez-Ramos |first1=Ignacio M. |last2=MarañóN |first2=Teodoro |last3=Lobo |first3=Jorge M. |last4=Verdú |first4=José R. |date=August 2007 |title=Acorn removal and dispersal by the dung beetle Thorectes lusitanicus : ecological implications |url=https://resjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2311.2007.00874.x |journal=Ecological Entomology |language=en |volume=32 |issue=4 |pages=349–356 |doi=10.1111/j.1365-2311.2007.00874.x |bibcode=2007EcoEn..32..349P |issn=0307-6946|hdl=10261/47760 |hdl-access=free }}</ref> Acorns have a large influence on small [[rodent]]s in their [[habitat]]s, as large acorn yields help rodent populations to grow.<ref>{{Cite web |title=Acorn Study {{!}} Research {{!}} Upland Hardwood Ecology and Management {{!}} SRS |url=https://www.srs.fs.usda.gov/uplandhardwood/research/article/acorn-study |access-date=2020-09-04 |website=srs.fs.usda.gov}}</ref>

Large mammals such as pigs, bears, and [[deer]] also consume large amounts of acorns; they may constitute up to 25% of the diet of deer in the autumn.<ref>{{Cite book |last=Barrett, Reginald H. |title=Proceedings of the symposium on the ecology, management, and utilization of California oaks, June 26–28 |publisher=USDA Forest Service General Technical Report PSW-044 |year=1980 |editor-last=Plumb, Timothy R. |pages=276–291 |chapter=Mammals of California Oak Habitats-Management Implications |chapter-url=http://www.fs.fed.us/psw/publications/documents/psw_gtr044/psw_gtr044.pdf}}</ref> In Spain, Portugal and the [[New Forest]] region of southern England, pigs are still turned loose in ''[[Dehesa (pastoral management)|dehesas]]'' (large oak [[grove (nature)|grove]]s) in the autumn, to fill and fatten themselves on acorns. Heavy consumption of acorns can, on the other hand, be toxic to other animals that cannot detoxify their [[tannin]]s, such as horses and cattle,<ref>{{Cite web |date=19 October 2011 |title=A bumper crop of acorns causes concern for those with horses |url=http://www.countryfile.com/news/bumper-crop-acorns-causes-concern-those-horses |access-date=27 January 2014 |website=Countryfile.com |publisher=Immediate Media Company}}</ref><ref name="Barringer">{{Cite web |last=Barringer |first=Sam |title=Acorns Can be Deadly |url=http://www.caf.wvu.edu/~forage/acorns/acorns.htm |url-status=dead |archive-url=https://web.archive.org/web/20140227141549/http://www.caf.wvu.edu/~forage/acorns/acorns.htm |archive-date=27 February 2014 |access-date=27 January 2014 |website=West Virginia University Extension Service}}</ref> especially if eaten in excess.<ref>{{Cite web |date=2013-11-27 |title=Acorns fatally poison 50 ponies in English forest |url=http://horsetalk.co.nz/2013/11/23/acorns-fatally-poison-50-ponies-english-forest/#axzz40efTYqgN |access-date=2017-01-06 |publisher=Horsetalk.co.nz}}</ref><ref>{{Cite web |title=Acorn Poisoning – Are Acorns Poisonous To Horses? |url=http://www.horse-advice.com/equestrian/equine-veterinary/acorns-poisonous.shtml |access-date=2017-01-06 |publisher=Horse-advice.com}}</ref><ref>{{Cite web |date=2002-09-15 |title=Acorns, Oaks and Horses: Tannin Poisoning |url=http://www.thewayofhorses.com/10_08_acorns.html |access-date=2017-01-06 |publisher=The Way of Horses}}</ref>

The [[larva]]e of some [[moth]]s and [[weevil]]s also live in young acorns, consuming the kernels as they develop.<ref>Brown, Leland R. (1979) ''Insects Feeding on California Oak Trees''in ''Proceedings of the Symposium on Multiple-Use Management of California's Hardwood Resources'', Timothy Plum and Norman Pillsbury (eds.).</ref>

Acorns are attractive to animals because they are large and thus efficiently consumed or cached. Acorns are also rich in nutrients. Percentages vary from species to species, but all acorns contain large amounts of [[protein]], [[carbohydrate]]s and [[fat]]s, as well as the minerals [[calcium]], [[phosphorus]] and [[potassium]], and the [[vitamin]] [[Niacin (nutrient)|niacin]]. Total [[food energy]] in an acorn also varies by species, but all compare well with other wild foods and with other nuts.<ref>{{Cite web |title=Nutrition Facts for Acorn Flour |url=http://www.nutritiondata.com/facts-001-02s02dn.html |access-date=2017-01-06 |publisher=Nutritiondata.com}}</ref>

Acorns also contain bitter [[tannin]]s, the amount varying with the species. Since tannins, which are plant [[polyphenol]]s, interfere with an animal's ability to [[metabolize]] protein, creatures must adapt in different ways to use the nutritional value acorns contain. Animals may preferentially select acorns that contain fewer tannins. When the tannins are metabolized in cattle, the tannic acid produced can cause [[ulceration]] and [[kidney]] failure.<ref name="Barringer" />

Animals that [[cache (biology)|cache]] acorns, such as jays and squirrels, may wait to consume some of these acorns until sufficient groundwater has [[percolate]]d through them to [[Leaching (chemical science)|leach]] out the tannins. Other animals buffer their acorn diet with other foods. Many insects, birds, and mammals metabolize tannins with fewer ill effects than do humans.

Species of acorn that contain large amounts of tannins are very bitter, [[astringent]], and potentially irritating if eaten raw. This is particularly true of the acorns of American [[Quercus rubra|red oaks]] and [[Pedunculate oak|English oaks]]. The acorns of [[white oak]]s, being much lower in tannins, are nutty in flavor; this characteristic is enhanced if the acorns are given a light roast before grinding.

Tannins can be removed by soaking chopped acorns in several changes of water, until the water no longer turns brown. Cold water leaching can take several days, but three to four changes of boiling water can leach the tannins in under an hour.<ref>{{Cite book |last=Tull |first=Delena |title=A practical guide to edible & useful plants : including recipes, harmful plants, natural dyes & textile fibers |date=1987 |publisher=Texas Monthly Press |isbn=9780877190226 |location=Austin, Tex. |oclc=15015652}}</ref> Hot water leaching (boiling) cooks the starch of the acorn, which would otherwise act like gluten in flour, helping it bind to itself. For this reason, if the acorns will be used to make flour, then cold water leaching is preferred.<ref>{{Cite news |title=Two Ways to Make Cold Leached Acorn Flour – Learn How with this Guide |work=The Spruce |url=https://www.thespruce.com/cold-leaching-and-preserving-acorn-flour-4007438 |access-date=2017-12-24 |archive-date=25 December 2017 |archive-url=https://web.archive.org/web/20171225035849/https://www.thespruce.com/cold-leaching-and-preserving-acorn-flour-4007438 |url-status=dead }}</ref>

Being rich in fat, acorn flour can spoil or [[Mold (fungus)|mold]]er easily and must be carefully stored. Acorns are also sometimes prepared as a massage oil.

Acorns of the white oak group, ''Leucobalanus'', typically start rooting as soon as they are in contact with the soil (in the fall), then send up the leaf shoot in the spring.

===Dispersal agents===

Acorns are too heavy for [[wind dispersal]], so they require other ways to spread. Oaks therefore depend on [[Biological dispersal|biological seed dispersal]] agents to move the acorns beyond the mother tree and into a suitable area for germination (including access to adequate water, sunlight and soil nutrients), ideally a minimum of {{convert|20–30|m|ft|-1|abbr=on}} from the parent tree.{{Citation needed|date=January 2010}}

Many animals eat unripe acorns on the tree or ripe acorns from the ground, with no reproductive benefit to the oak, but some animals, such as [[squirrel]]s and [[jay]]s serve as seed dispersal agents. Jays and squirrels that scatter-hoard acorns in caches for future use effectively plant acorns in a variety of locations in which it is possible for them to germinate and thrive.

Even though jays and squirrels retain remarkably large mental maps of cache locations and return to consume them, the odd acorn may be lost, or a jay or squirrel may die before consuming all of its stores. A small number of acorns manage to germinate and survive, producing the next generation of oaks.

Scatter-hoarding behavior depends on jays and squirrels associating with plants that provide good packets of food that are nutritionally valuable, but not too big for the dispersal agent to handle. The beak sizes of jays determine how large acorns may get before jays ignore them.

Acorns germinate on different schedules, depending on their place in the oak family. Once acorns sprout, they are less nutritious, as the seed tissue converts to the indigestible [[lignin]]s that form the root.<ref>{{Citation |last=Janzen |first=Daniel H. |title=Seed Predation by Animals |journal=Annual Review of Ecology and Systematics |volume=2 |pages=465–492 |year=1971 |issue=1 |editor-last=Richard F. Johnson, Peter W. Frank and Charles Michner |doi=10.1146/annurev.es.02.110171.002341 |jstor=2096937|bibcode=1971AnRES...2..465J }}</ref>

{{nutritionalvalue
| name=Acorn, raw
| water=27.9 g
| kJ=1619
| protein=6.15 g
| fat=23.85 g
| satfat=3.102 g
| monofat = 15.109 g
| polyfat = 4.596 g
| carbs=40.75 g
| calcium_mg=41
| copper_mg = .621
| iron_mg=0.79
| magnesium_mg=62
| phosphorus_mg=79
| potassium_mg=539
| sodium_mg=0
| manganese_mg=1.337
| zinc_mg=0.51
| vitC_mg=0.0
| thiamin_mg=0.112
| riboflavin_mg=0.118
| niacin_mg=1.827
| pantothenic_mg=0.715
| vitB6_mg=0.528
| folate_ug=87
| vitA_ug=2
<!-- amino acids -->
| tryptophan=0.074 g
| threonine=0.236 g
| isoleucine=0.285 g
| leucine=0.489 g
| lysine=0.384 g
| methionine=0.103 g
| cystine=0.109 g
| phenylalanine=0.269 g
| tyrosine=0.187 g
| valine=0.345 g
| arginine=0.473 g
| histidine=0.170 g
| alanine=0.350 g
| aspartic acid=0.635 g
| glutamic acid=0.986 g
| glycine=0.285 g
| proline=0.246 g
| serine=0.261 g
| source_usda=1
| note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/170157/nutrients Link to USDA Database entry]
}}

==Uses==
In some cultures, acorns once constituted a dietary [[Staple food|staple]], though they have largely been replaced by [[Food grain|grain]]s and are now typically considered a relatively unimportant food, except in some Native American and Korean communities.

Several cultures have devised traditional acorn-leaching methods, sometimes involving specialized tools, that were traditionally passed on to their children by word of mouth.<ref>{{Cite web |title=Indigenous Food and Traditional Recipes |url=http://www.nativetech.org/recipes/recipe.php?recipeid=115 |access-date=2017-01-06 |publisher=NativeTech}}</ref><ref>{{Cite web |title=Cooking With Acorns |url=http://www.siouxme.com/acorn.html |access-date=2017-01-06 |publisher=Siouxme.com}}</ref>

===Culinary===
{{Cookbook}}

Acorns served an important role in early human history and were a source of food for many cultures around the world.<ref>{{Citation |last=Bainbridge |first=D. A. |title=Use of acorns for food in California: past, present and future |date=12–14 November 1986 |url=http://www.ecocomposite.org/native/UseOfAcornsForFoodInCalifornia.doc |access-date=1 September 2010 |archive-url=https://web.archive.org/web/20101027113825/http://ecocomposite.org/native/UseOfAcornsForFoodInCalifornia.doc |url-status=dead |place=San Luis Obispo, CA. |publisher=Symposium on Multiple-use Management of California's Hardwoods |archive-date=27 October 2010}}</ref> For instance, the [[Ancient Greek cuisine|Ancient Greek]] lower classes and the Japanese (during the [[Jōmon]] period)<ref name="HabuJunko2004">{{Cite book |last1=Junko Habu |url=https://books.google.com/books?id=vGnAbTyTynsC |title=Ancient Jomon of Japan |last2=Habu Junko |date=29 July 2004 |publisher=Cambridge University Press |isbn=978-0-521-77670-7}}</ref> would eat acorns, especially in times of famine.{{Citation needed|date=October 2008}} In ancient [[Iberia]] they were a staple food, according to [[Strabo]]. Despite this history, acorns rarely form a large part of modern diets and are not currently cultivated on scales approaching that of many other nuts. However, if properly prepared (by selecting high-quality specimens and [[leaching (chemistry)|leaching]] out the bitter tannins in water), acorn meal can be used in some recipes calling for grain flours. In antiquity, [[Pliny the Elder]] noted that acorn flour could be used to make bread.<ref name="Met">{{Cite web |last=Alphonso |first=Christina |date=5 November 2015 |title=Acres of Acorns |url=http://www.metmuseum.org/blogs/in-season/2015/acres-of-acorns |access-date=15 April 2017 |website=The Metropolitan Museum of Art, i.e. The Met Museum}}</ref> Varieties of oak differ in the amount of tannin in their acorns. Varieties preferred by Native Americans, such as ''[[Quercus kelloggii#Uses|Quercus kelloggii]]'' (California black oak), may be easier to prepare or more palatable.<ref>{{Cite book |last=Derby, Jeanine A. |title=Proceedings of the symposium on the ecology, management, and utilization of California oaks, June 26–28 |publisher=USDA Forest Service General Technical Report PSW-044 |year=1980 |editor-last=Plumb, Timothy R. |pages=360–361 |chapter=Acorns-Food for Modern Man |chapter-url=http://www.fs.fed.us/psw/publications/documents/psw_gtr044/psw_gtr044.pdf}}</ref>

In Korea, an edible jelly named ''[[dotorimuk]]'' is made from acorns, and ''[[dotori guksu]]'' are Korean noodles made from acorn flour or starch. In the 17th century, a juice extracted from acorns was administered to habitual drunkards to cure them of their condition or else to give them the strength to resist another bout of drinking.{{Citation needed|date=November 2010}}{{clarify|date=October 2020}}

Roasted acorn flour is a main ingredient in sweet cakes special to [[Kurdish population|Kurdish]] areas of [[Iran]] and [[Iraq]].<ref>{{cite book |last1=Hooper |first1=David |last2=Field |first2=Henry |author2-link=Henry Field (anthropologist) |title=Plants and Drugs of Iran and Iraq |date=1937 |publisher=[[Field Museum of Natural History]] |page=161}}</ref><ref>{{cite journal |last1=Salih |first1=Rafiq Mohamed |last2=Sabir |first2=Dlir Amin |last3=Hawramee |first3=Othman K. |title=Effect of sweet acorn flour of common oak (''Quercus aegilops'' L.) on locally Iraqi pastry (kulicha) products |journal=Journal of Zankoy Sulaimani - Part A |date=October 2013 |volume=16 |issue=special |pages=244–249 |doi=10.17656/jzs.10327|doi-broken-date=20 March 2025 }}</ref>

Acorns have frequently been used as a [[coffee substitute]], particularly when [[coffee]] was unavailable or rationed. The [[Confederate States of America|Confederates]] in the [[American Civil War]] and [[Germany|Germans]] during [[World War I]] (when it was called ''[[Ersatz]]'' coffee), which were cut off from coffee supplies by [[Union blockade|Union]] and Allied [[blockade]]s respectively, are particularly notable past instances of this use of acorns.

====Use by Native Americans====
Acorns are a traditional food of many [[Indigenous peoples of the Americas|indigenous]] peoples of North America, and long served an especially important role for [[Indigenous peoples of California|Californian Native Americans]], where the ranges of several species of oaks overlap, increasing the reliability of the resource.<ref>{{Citation |last=Suttles |first=Wayne |title=(Review of) Ecological Determinants of Aboriginal California Populations, by Martin A. Baumhoff |work=American Anthropologist |volume=66 |issue=3 |pages=676 <!-- note that this article is a review of the Baumhoff article --> |year=1964 |doi=10.1525/aa.1964.66.3.02a00360 |doi-access=free}}</ref> One ecology researcher of [[Yurok people|Yurok]] and [[Karuk people|Karuk]] heritage reports that "his traditional acorn preparation is a simple soup, cooked with hot stones directly in a basket," and says he enjoys acorns eaten with "grilled [[salmon]], [[Huckleberry|huckleberries]] or [[seaweed]]."<ref>{{Cite web |last=Prichep |first=Deena |date=2014-11-02 |title=Nutritious Acorns Don't Have To Just Be Snacks For Squirrels |url=https://www.npr.org/blogs/thesalt/2014/10/24/358527018/nutritious-acorns-dont-have-to-just-be-snacks-for-squirrels |access-date=2014-11-03 |website=The Salt : NPR}}</ref>
Unlike many other plant foods, acorns do not need to be eaten or processed right away, but may be stored for a long time, much as [[squirrel]]s do. In years that oaks produced many acorns, Native Americans sometimes collected enough acorns to store for two years as insurance against poor acorn production years.

After drying in the sun to discourage [[Mold|mould]] and [[germination]], acorns could be cached in hollow trees or structures on poles to keep them safe from mice and squirrels. Stored acorns could then be used when needed, particularly during the winter when other resources were scarce. Acorns that germinated in the fall were shelled and pulverized before those germinating in spring.{{citation needed|date=December 2020}} Because of their high fat content, stored acorns can become rancid. Moulds may also grow on them.

The lighting of ground fires killed the larvae of [[Blastobasis glandulella|acorn moth]]s and [[acorn weevil]]s by burning them during their dormancy period in the soil.  The pests can infest and consume more than 95% of an oak's acorns.{{citation needed|date=April 2015}}

Fires also released the nutrients bound in dead leaves and other plant debris into the soil, thus fertilizing oak trees while clearing the ground to make acorn collection easier. Most North American oaks tolerate light fires, especially when consistent burning has eliminated woody fuel accumulation around their trunks. Consistent burning encouraged oak growth at the expense of other trees less tolerant of fire, thus keeping oaks dominant in the landscapes.{{citation needed|date=April 2015}}

In the [[San Francisco Bay Area]] acorns found were often associated with grinding tools. [[Stone tools]] like hammerstone and anvil, millingstones, and [[mortar and pestle]] help crack open the acron and grind the arcon into dust.<ref>Buonasera, T.Y. (2013). More than acorns and small seeds: A diachronic analysis of mortuary-associated ground stone from the south San Francisco Bay area. Journal of Anthropological Archaeology, 32(2), 190–211. https://doi.org/10.1016/j.jaa.2013.01.003
</ref>

Oaks produce more acorns when they are not too close to other oaks and thus competing with them for sunlight, water and soil nutrients. The fires tended to eliminate the more vulnerable young oaks and leave old oaks which created open [[oak savanna]]s with trees ideally spaced to maximize acorn production.

<gallery widths="200px" heights="200px">
File:Acorn mortar holes friant ca.jpg|[[Mortar holes]] for pounding acorns into flour, [[Lost Lake, California]]
File:Photograph with text showing a Chuckachancy woman preparing acorns for grinding, California. This is from a survey... - NARA - 296297 (cropped).jpg|[[Yokuts people|Chuckachancy]] women pause in their work preparing acorns for grinding, California, {{circa| 1920}}
</gallery>

===In culture===
[[File:One of General Sherman's Campaign Hat.jpg|thumb|Campaign hat worn by [[William Tecumseh Sherman|General Sherman]]]]

====Art====
A [[Motif (art)|motif]] in [[Roman architecture]], also popular in Celtic and Scandinavian art, the acorn symbol is used as an [[Ornament (architecture)|ornament]] on [[cutlery]], furniture, and jewelry; it also appears on [[finial]]s at [[Westminster Abbey]].

In the [[Artemis Fowl]] book series, "The Ritual" describes the method used by faeries to regenerate their magical powers.<ref>{{Cite book |last=Colfer |first=Eoin |url=https://www.worldcat.org/title/46493219 |title=Artemis Fowl |date=2001 |publisher=Viking |isbn=9780670899623 |location=London |pages=277}}</ref>

====Military symbolism====

The acorn was used frequently by both [[Union (American Civil War)|Union]] and [[Military forces of the Confederate States|Confederate]] forces during the [[American Civil War]].<ref>{{Cite web |title=Chikamauga and Chattanooga |url=https://www.nps.gov/chch/faqs.htm |access-date=2022-10-27 |department=Frequently Asked Questions |publisher=U.S. Forest Service|date=2022-10-27}}</ref> Modern [[US Army]] Cavalry Scout [[campaign hat]]s still retain traces of the acorn today.

====Contemporary use as symbol====
The acorn is the symbol for the [[National Trails]] of [[England and Wales]], and is used for the [[waymarking|waymarks]] on these paths.<ref>{{Cite web |title=National Trail Acorn |url=http://www.nationaltrail.co.uk/hadrianswall/publications.asp?PageId=276 |url-status=dead |archive-url=https://web.archive.org/web/20120314170425/http://www.nationaltrail.co.uk/hadrianswall/publications.asp?PageId=276 |archive-date=14 March 2012 |access-date=9 October 2010 |website=National Trails}}</ref> The acorn, specifically that of the white oak, is also present in the symbol for the [[University of Connecticut]].<ref>{{Cite web |title=University of Connecticut |url=http://uconn.edu/ |url-status=live |archive-url=https://web.archive.org/web/20101104073123/http://www.uconn.edu/ |archive-date=4 November 2010 |access-date=5 November 2010}}</ref>

Acorns are also used as [[Charge (heraldry)|charges]] in [[heraldry]].

<gallery mode="packed">
Acorn Britain National Trails Symbol.svg|Acorn waymark for [[National Trails]] in England and Wales
1410EcudQ.svg|Acorn in the coat of arms of the du Quesne family
Tammela.vaakuna.svg|Oak branch with two acorns in the coat of arms of [[Tammela, Finland|Tammela]]
</gallery>

==See also==
* [[Knopper gall]]

==References==
{{Reflist}}

== External links ==
* {{Commons category-inline}}
* {{Cookbook-inline|Acorn}}

{{Nuts}}

{{Authority control}}

[[Category:Acorns| ]]
[[Category:Quercus]]
[[Category:Edible nuts and seeds]]
[[Category:Ornaments]]
[[Category:Pseudocereals]]
[[Category:Plants used in Native American cuisine]]
[[Category:Pre-Columbian Native American cuisine]]
[[Category:Post-Columbian Native American cuisine]]
[[Category:Heraldic charges]]
[[Category:Californian cuisine]]