Citrus fruits are the edible fruits of plants belonging to the genus Citrus and the closely related genus Fortunella, both of the family rutaceae. The plants are spiny evergreen shrubs or trees bearing white or purplish flowers. The fruits, classes botanically as a type of berry called a hesperidium, are leathery skinned with a fleshy interior divided into sections.
Citrus are native to Southeast Asia and the East Indies and have been cultivated in those areas for milennia. Most are introduced into Europe in the 12th century and are now grown in tropical and subtropical areas throughout the world, particularly in North and South America, the Mediteranean region, Australia, and South Africa.
The Important of Citrus Species
Commercially grown fruits belong to one of eight major citrus species. The most important is the sweet (Orange, C. sinensis, which includes the popular Valencia and navel in the United States, the "blood" (red-pigmented) oranges of the Mediteranean, and the Shamout; or Jaffa, orange of Israel.
Sour, or Seville, orange, C. aurantium, are grown principally in Seville region and are widely used in making marmalade. A sour orange variety, Bergamot, is grown in Italy for its aromatic rind.
Mandarins, or Tangerines. C. reticulata, have a smaller fruit and a looser peel than do orange varieties. Lemon, C. limon, are grown commercially in many varieties. Because the lemon is less hardy than the orange, it is cultivated mainly in regions of low frost hazard.
Limes, C. aurantiifolia; comprise two major groups, the small fruited West Indian, or Key, lime , and the larger Persian, or Tahiti, lime. The lime is the most frost tender of the citrus group and is cultivated primarily in tropical areas.
Citroen, C. medica, are grown for their peel, primarily in Italy, Corsica, and Israel. Pomelos, or shaddocks, C. maxima, are large, grape fruitlike fruit grown mostly in tropical Southeast Asia, although two new subtropical varieties have been develope in California.
Grapefruit, C. paradisi, are through to be a hybrid of the pomelo. In the United States they are most widely grown as a white, seedless fruits or as a red pigmented mutation.