Occurrence
An actual survey of approximately 7 million clovers found the frequency to be about 5000 to 1, 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.Cause
It is debated whether the fourth leaf is caused genetically or environmentally. Its relative rarity (1 in 5,000 clovers) suggests a possible recessive gene appearing at a low frequency. Alternatively, four-leaf clovers could be caused by 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. 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. 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. 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 genetically engineered ingredient to the plants to encourage the aberration (there are, however, widely availableMulti-leaved cultivars
There are some cultivars of white clover ('' Trifolium repens'') which regularly produce more than three leaflets, including purple-leaved ''T. repens'' "Purpurascens Quadrifolium" and green-leaved ''T. repens'' "Quadrifolium". 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.Other species
Other plants may be mistaken for, or misleadingly sold as, "four-leaf clovers"; for example, '' Oxalis tetraphylla'' is a species of wood sorrel with leaves resembling a four-leaf clover. Other species that have been sold as "four-leaf clovers" include ''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". In an 1877 letter to ''St.Nicholas Magazine'', an 11-year-old girl, who wrote, "Did the fairies ever whisper in your ear, that a four-leaf clover brought good luck to the finder?"Symbolic usage
* Italian automobile maker 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. As of 2022, the ''quadrifoglio'' is used on the company's race liveries. * Los Angeles-based space exploration company 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. * Celtic Football Club, anMeanings
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. Others say that four-leaf clovers granted the power to see fairies, or that they are related to Saint Patrick's use of the shamrock to explain the Christian doctrine of the Holy Trinity to the Irish.See also
* Fern flower * ShamrockReferences
{{Superstitions Trifolium Luck Lucky symbols de:Klee#Das vierblättrige Kleeblatt