View source for Biology:Four-leaf clover

{{short description|Variation of the common clover, rare and said to bring good luck}}
[[File:Four-leaf Clover Trifolium repens 2.jpg|thumb|Four-leaf white clover (''Trifolium repens'').]]
The '''four-leaf clover''' is a rare variation of the common three-leaf [[Biology:Clover|clover]]. According to traditional sayings, such clovers bring good luck,<ref>{{cite book |title= Black Cats & Four-Leaf Clovers: The Origins of Old Wives' Tales and Superstitions in Our Everyday Lives |author= Harry Oliver |edition= reprint |publisher= Penguin |year= 2010 |isbn= 9781101442814}}</ref> though it is not clear when or how this idea began. One early mention of "Fower-leafed or purple grasse" is from 1640 and simply says that it was kept in gardens because it was "good for [[Medicine:Purpura|the purples]] in children or others".<ref>Parkinson J. 1640. ''Theatrum Botanicum: The Theater of Plants or An Herball of Large Extent''. Tho. Cotes. Publisher, London, Pp 1110-1112.</ref>

==Occurrence==
A 2017 survey of approximately 7 million clovers in central Europe found the frequency to be about 5000 to 1 (one four-leaf clover for every ~5000 normal three-leaf clovers), twice the commonly stated probability of 10,000 to 1. According to this survey, the frequency of a five-leaf clover is ~24,400 to 1, and of a six-leaf clover is ~312,500 to 1.<ref name="auto">{{cite web |last1=Sperling |first1=Uli |title=How rare are four-leaf clovers really? |url=http://www.sharetheluck.ch/single-post/How-rare-are-four-leaf-clovers-really |website=Share the Luck |archive-url=https://web.archive.org/web/20201205113712/http://www.sharetheluck.ch/single-post/How-rare-are-four-leaf-clovers-really |archive-date=5 December 2020 |date=24 July 2017}}</ref>

Clovers can have more than four leaves. Five-leaf clovers are less commonly found naturally than four-leaf clovers;<ref>{{cite web |last1=Hershey |first1=David |title=Re: how common is a five leaf clover? |url=https://www.madsci.org/posts/archives/2000-03/953257839.Bt.r.html |website=MadSci Network |date=16 March 2000}}</ref><ref>{{cite web |title=Facts About Five-leaf Clovers |url=http://www.fourleafclover.com/5fact.html |website=Clovers Online |publisher=Clover Specialty Company |archive-url=https://web.archive.org/web/20081227003539/http://www.fourleafclover.com/5fact.html |archive-date=27 December 2008 |date=2004}}</ref> however, they, too, have been successfully cultivated.<ref>{{cite web |title=Five-leaf clover |url=http://register-news.com/local/x2143197334/Five-leaf-clover |publisher=Mt. Vernon Register-News |archive-url=https://archive.today/20120908020022/http://www.register-news.com/local/local_story_288095608.html |archive-date=8 September 2012 |date=14 October 2008}}</ref> Some four-leaf clover collectors, particularly in Ireland, regard the five-leaf clover, known as a rose clover, as a particular prize.<ref>Mabey, Richard, ''Flora Britannica'', p. 225 (citing Edward and Helene Wenis of Leonia, New Jersey, U.S., writing in ''BSBI News'', 56, 1990)</ref> The most leaves ever found on a single clover stem (''Trifolium repens L''.) is 56 and was discovered by Shigeo Obara of Hanamaki, Iwate, Japan, on 10 May 2009.<ref>{{cite web |title=Most leaves on a clover |url=https://www.guinnessworldrecords.com/world-records/most-leaves-on-a-clover/ |website=Guinness World Records |access-date=20 November 2011 |date=10 May 2009}}</ref><ref>{{cite web |title=WEEK IN PHOTOS: Unlucky Kangaroo, 56-Leaf Clover, More |url=http://news.nationalgeographic.com/news/2009/05/photogalleries/week-in-news-pictures-130/photo4.html |publisher=National Geographic |access-date=17 March 2019 |archive-url=https://web.archive.org/web/20090518200543/http://news.nationalgeographic.com/news/2009/05/photogalleries/week-in-news-pictures-130/photo4.html |archive-date=18 May 2009 |date=12 May 2009}}</ref>

Collectors have reached records as high as 160,000 four-leaf clovers in a lifetime.<ref>{{cite news |last1=George |first1=Jason |title=160,000? That's a lot of luck |url=https://www.chicagotribune.com/news/ct-xpm-2008-03-17-0803160132-story.html |access-date=11 January 2020 |work=Chicago Tribune |date=17 March 2008}}</ref> The world record for number of four-leaf clovers collected in one hour is 166, set by American Katie Borka on June 23, 2018.<ref>{{cite web |last1=Ross |first1=Hailey |title=Spotsylvania girl charms her way into Guinness Book of World Records by finding 166 four-leaf clovers |url=https://fredericksburg.com/spotsylvania-girl-charms-her-way-into-guinness-book-of-world/article_42685430-1333-5d1f-87d2-a8b723c70788.html |website=Fredericksburg.com |publisher=The Free Lance-Star |date=25 June 2018 |url-access=subscription}}</ref>

==Cause==
[[File:Four Leaf Clover (7258825680).jpg|thumb|upright|A four-leaf clover amongst others with three leaves]]
It is debated whether the fourth leaf is caused genetically or environmentally. Its relative rarity (1 in 5,000 clovers<ref name="auto"/>) suggests a possible recessive gene appearing at a low frequency. Alternatively, four-leaf clovers could be caused by [[Biology:Somatic mutation|somatic mutation]] or a developmental error of environmental causes. They could also be caused by the interaction of several genes that happen to segregate in the individual plant. It is possible all four explanations could apply to individual cases. This means that multiple four-leaf clovers could be found in the same cloverplant.<ref>{{cite book |title= Compendium of Symbolic and Ritual Plants in Europe: Herbs |volume= 2 |author= Marcel Cleene, Marie Claire Lejeune |publisher= Man & Culture |year= 2002}}</ref>

Researchers from the University of Georgia have reported finding the gene that turns ordinary three-leaf clovers into the coveted four-leaf types. Masked by the three-leaf gene and strongly influenced by environmental condition, molecular markers now make it possible to detect the presence of the gene for four-leaves and for breeders to work with it. The results of the study, which also located two other leaf traits in the white-clover genome, were reported in the July/August 2010 edition of ''Crop Science'', published by the Crop Science Society of America.<ref>Tashiro, R.M., et al. ''[https://www.crops.org/publications/cs/abstracts/50/4/1260 Leaf Trait Coloration in White Clover and Molecular Mapping of the Red Midrib and Leaflet Number Traits]''. Crop Science 7 June 2010.</ref>

The other leaf traits, the red fleck mark and red midrib, a herringbone pattern that streaks down the center of each leaflet in a bold red color, were mapped to nearby locations, resolving a century-old question as to whether these leaf traits were controlled by one gene or two separate genes.

White clover has many genes that affect leaf color and shape, and the three in the study were very rare. These traits can be quite attractive, particularly if combined with others, and can turn clover into an ornamental plant for use in flower beds.<ref>[http://parrottlab.uga.edu/parrottlab/Clover/index.htm] The Georgia White Clover Ornamental Collection.</ref>

There are reports of farms in the US which specialize in four-leaf clovers, producing as many as 10,000 a day (to be sealed in plastic as "lucky charms") by introducing a [[Biology:Genetic engineering|genetically engineered]] ingredient to the plants to encourage the aberration (there are, however, widely available [[Biology:Cultivar|cultivar]]s that regularly produce leaves with multiple leaflets&nbsp;– see below).<ref>Mabey, Richard, Ibid, p. 225</ref>

==Multi-leaved cultivars==
[[File:Five-leaf clover.jpg|thumb|A five-leaf ''Trifolium repens'']]
There are some cultivars of white clover (''[[Biology:Trifolium repens|Trifolium repens]]'') which regularly produce more than three leaflets, including purple-leaved ''T. repens'' "Purpurascens Quadrifolium" and green-leaved ''T. repens'' "Quadrifolium".<ref>Lord, Tony (ed), ''RHS Plant Finder 2006–2007'', (20th edition), Dorling Kindersley, London, 2006, p. 743. {{ISBN|1-4053-1455-9}}</ref> Some clovers have more spade shape leaves, rather than the usual rounded ones. This may be a genetic mutation. Some genetic mutations in clovers include spade-like shaped leaves or a dotted rusty colour on the leaves.

''Trifolium repens'' "Good Luck" is a cultivar which has three, four, or five green, dark-centered leaflets per leaf.<ref>[http://www.killerplants.com/weird-plants/20030710.asp Killerplants.com] {{webarchive|url=https://web.archive.org/web/20081011052758/http://www.killerplants.com/weird-plants/20030710.asp |date=2008-10-11 }} (photo)</ref>

==Other species==
Other plants may be mistaken for, or misleadingly sold as, "four-leaf clovers"; for example, ''[[Biology:Oxalis tetraphylla|Oxalis tetraphylla]]'' is a species of wood sorrel with leaves resembling a four-leaf clover.<ref>''[https://www.amazon.com/dp/0762414731 The Four Leaf Clover Kit (Mega Mini Kits) (Paperback)]''. Amazon review. 12 September 2006.</ref><ref>''[http://www.fourleafclover.com/cgi-bin/i-merchant/i-merchant.cgi?page=seed.html Good Luck Plant Kit] {{webarchive|url=https://web.archive.org/web/20081227084529/http://www.fourleafclover.com/cgi-bin/i-merchant/i-merchant.cgi?page=seed.html |date=2008-12-27 }}''. FourLeafClover.com. Retrieved 7 December 2008.</ref> Other species that have been sold as "four-leaf clovers" include ''[[Biology:Marsilea quadrifolia|Marsilea quadrifolia]]''.<ref>''[http://www.lollysmith.com/allabsham.html All About Shamrocks Four-Leaf Clovers] {{webarchive|url=https://web.archive.org/web/20081214082912/http://www.lollysmith.com/allabsham.html |date=2008-12-14 }}''. LollySmith.com. Retrieved 7 December 2008.</ref><ref>Keenan, Susan M. ''[http://www.hotfact.com/the-four-leaf-clover.html The Four Leaf Clover] {{webarchive|url=https://web.archive.org/web/20090130091837/http://www.hotfact.com/the-four-leaf-clover.html |date=2009-01-30 }}''. HotFact.com. 11 March 2008.</ref>

==As a good luck charm==
A description from 1869 says that four-leaf clovers were "gathered at night-time during the full moon by sorceresses, who mixed it with vervain and other ingredients, while young girls in search of a token of perfect happiness made quest of the plant by day".<ref>Masters MT. 1869. ''Vegetable Teratology, An Account of the Principal Deviations from the Usual Construction of Plants''. Robert Hardwicke Publisher, London, P 356.</ref>

In an 1877 letter to ''St.{{nbs}}Nicholas Magazine'', an 11-year-old girl wrote, "Did the fairies ever whisper in your ear, that a four-leaf clover brought good luck to the finder?"<ref>Child, Madge. 1877. In a letter titled "Four-Leaved Clovers," (St. Nicholas; an Illustrated Magazine for Young Folks), Volume 4, pp. 634-5, in the subsection of letters called "Jack-in-the-Pulpit", July 1877.</ref>

==Symbolic usage==
[[File:Lääne-Nigula valla vapp.svg|thumb|upright=0.7|Four-leaf clover pictured in the coat of arms of Lääne-Nigula Parish]]
[[File:Nordic Agrarian party logos.jpg|thumb|The Four leaf clover is used as a symbol by multiple agrarian political parties in Northern and Eastern Europe]]
* Italian automobile maker [[Company:Alfa Romeo|Alfa Romeo]] uses a ''quadrifoglio'' (four-leaf clover) icon to delineate its racing cars and performance-oriented road models. This tradition started in the 1923 Targa Florio race, when driver Ugo Sivocci decorated his car with a green clover on a white background.{{citation needed|date=May 2022}} As of 2022, the ''quadrifoglio'' is used on the company's race liveries.<ref>{{cite web|url=https://www.alfaromeo.com/alfa-romeo-world/passion/alfa-news/2022/F1#|title=The Alfa Romeo F1 Team ORLEN. C42 is born|website=Alfa Romeo|date=2022|accessdate=15 May 2022}}</ref>
* Los Angeles-based space exploration company [[Company:SpaceX|SpaceX]] includes a four-leaf clover on each space mission embroidered patch as a good luck charm. Inclusion of the clover has become a regular icon on SpaceX's flight patches ever since the company's first successful Falcon 1 rocket launch in 2008, which was the first mission to feature a clover "for luck" on its patch.<ref>"[http://www.space.com/25010-spacex-space-station-mission-patch.html SpaceX's 3rd Space Station Resupply Flight Gets 3-Sided Mission Patch]". space.com. Retrieved 23 February 2015</ref>
* Celtic Football Club, an association football team from Glasgow, Scotland, have used the four leaf clover as the club's official badge for over 40 years.
* Former Japanese game developer studio [[Company:Clover Studio|Clover Studio]] used a four-leaf clover as their logo.
* Several businesses and organisations use a four-leaf clover in their logos to signify Celtic origins.<ref>{{Cite web|url=http://www.cloverpark.k12.wa.us/|title=Clover Park School District Homepage|website=www.cloverpark.k12.wa.us}}</ref><ref>{{Cite web|url=https://cloverpub.com.br/|title=Clover Pub - European Pub|website=cloverpub.com.br}}</ref><ref>{{Cite web|url=http://www.celtic-computers.co.uk/|title=Celtic Computers &#124; Laptop & PC Computer Repair|website=www.celtic-computers.co.uk}}</ref>
* The global network of youth organizations 4-H uses a green four-leaf clover with a white H on each leaf.<ref>"[https://www.nal.usda.gov/exhibits/speccoll/exhibits/show/poster-collections/elsie-carper-collection-on-ext Elsie Carper Collection on Extension Service, Home Economics, and 4-H]". usda.gov. Retrieved 11 March 2016</ref>
* The logo of the New Jersey Lottery features an outline of the state in white on a green four-leaf clover printed on a lottery draw machine ball.
* The English-language imageboard [[Social:4chan|4chan]] features a four-leaf clover in its logo as a nod to its predecessor, the Japanese site Futaba Channel (2chan), whose name means two leaves, leading 4chan to be referred to in Japan as yotsuba, meaning four leaves.
* Traditional symbol of agrarian parties popularized by Republican Party of Farmers and Peasants, Bulgarian Agrarian National Union, People's Party and International Agrarian Bureau in interwar period. Used until today among others by Polish People's Party, [[Social:Estonian Centre Party|Estonian Centre Party]] and Nordic agrarian parties.
*In Japan, the Green Cars of [[Engineering:Shinkansen|Shinkansen]] use a four-leaf clover logo.
*Jewelry brand Van Cleef & Arpels the Alhambra lines feature motifs of four-leaf clover.<ref>{{Cite web |date=2022-09-14 |title=How Van Cleef & Arpels Got Its Four-Leaf Clover {{!}} Barnebys Magazine |url=https://www.barnebys.com/blog/how-van-cleef--arpels-got-its-four-leaf-clover |access-date=2024-01-09 |website=Barnebys.com |language=en-US}}</ref>

==Meanings==
Some folk traditions assign a different attribute to each leaf of a clover. The leaves have been used by Christians to represent hope, faith, love and luck.<ref>{{cite book |last1=Webster |first1=Richard |title=The Encyclopedia of Superstitions |date=2008 |publisher=[[Unsolved:Llewellyn Worldwide|Llewellyn Worldwide]] |isbn=9780738725611 |page=61 |url=https://books.google.com/books?id=m1-xCL47_7QC |access-date=18 July 2022}}</ref> Others say that four-leaf clovers granted the power to see fairies, or that they are related to Saint Patrick's use of the [[Religion:Shamrock|shamrock]] to explain the Christian doctrine of the Holy Trinity to the Irish.<ref>{{cite web|url=https://www.thebalanceeveryday.com/interesting-4-leaf-clover-facts-4117192|title=11 Juicy Facts About Four-Leaf Clovers|author=Grauschopf, Sandra|date=November 20, 2019|website=thebalanceeveryday.com}}</ref>{{better source needed|date=July 2022}}{{commons category}}

==See also==
*Fern flower

==References==
{{Reflist|30em}}

{{Superstitions}}

[[Category:Trifolium]]

de:Klee#Das vierblättrige Kleeblatt

{{Sourceattribution|Four-leaf clover}}