Clover (Trifolium), or trefoil, is a genus of about 300 species of plants in the pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes on mountains in the tropics. They are small annual, biennial, or short-lived perennial herbaceous plants. The "shamrock" of popular iconography is sometimes considered to be young clover. The scientific name derives from the Latin tres, "three", and folium, "leaf", so called from the characteristic form of the leaf, which has three leaflets (trifoliate); hence the popular name trefoil. Clovers are used as food plants by the larvae of some Lepidoptera (butterfly and moth) [edit] Symbolism and mythology A four-leaf clover A five-leaf cloverShamrock, the traditional Irish symbol coined by Saint Patrick for the Holy Trinity, is commonly associated with clover, though sometimes with Oxalis species, which are also trifoliate (i.e., they have three leaves).Clovers occasionally have leaves with four leaflets, instead of the usual three. These four-leaf clovers, like other rarities, are considered lucky. Clovers can also have five, six, or more leaves, but these are more rare. The most ever recorded is twenty-one,[1] a record set in June 2008 by the same man who held the prior record and the current Guinness World Record of eighteen.[2] Unofficial claims of discovery have ranged as high as twenty-seven.[1]A common idiom is "to be in clover", meaning to be living a carefree life of ease, comfort, or prosperity. This stems from the historical use of clover as green manure planted after harvesting a crop; a farmer whose fields were "in the clover" was finished for the season.The cloverleaf interchange is named for the resemblance to the leaves of a (four-leafed) clover when viewed from the air.
