Facts about Citrus
The earliest known mention of citrus (citrons and lemons) in Indian writings is from around 800 B.C.E.
The hybridized types of citrus may or may not be recognized as species according to different taxonomies.
Citrus is good source of vitamin C (ascorbic acid), which is needed for a range of essential metabolic reactions and is a critical cofactor in the formation of collagen.
Cultivated Citrus may be derived from as few as three or four ancestral species.
Citrus is a genus of flowering plants in the family Rutaceae (orange family) and a common name for edible fruits of this genus (and sometimes related genera).
All commercial citrus cultivation uses trees produced not by seeds but by grafting the desired fruiting cultivars onto rootstocks selected for disease resistance and hardiness.
Citrus is likely the most widely planted fruit for direct human consumption in the world (Katz and Weaver 2003).
The numerous Citrus hybrids of natural and cultivated origin include commercially important fruit such as the orange, lemon, lime, grapefruit, and some tangerines.
The color of citrus fruits only develops in climates with a (diurnal) cool winter.
Citrus fruits may be consumed fresh, as juice, or preserved.
Compared to many "normal green" shrubs, citrus better tolerates poor container care.
The citrus plants are small trees or large shrubs, reaching 5 to 15 meters tall, with spiny shoots and alternately arranged evergreen leaves with an entire margin.
Citrus fruits are notable for their fragrance, partly due to flavonoids (secondary metabolites) and limonoids ( phytochemicals) contained in the rind, and most are juice-laden.
Many citrus fruits are picked while still green, and ripened while in transit to supermarkets.
Major commercial citrus growing areas include southern China, the Mediterranean Basin (including Southern Spain), South Africa, Australia, the southernmost United States, and parts of South America.
Citrus trees grown in tubs and wintered under cover were a feature of Renaissance gardens, once glass-making technology enabled sufficient expanses of clear glass to be produced.
More astringent citrus, such as lemons and limes are generally not eaten on their own.
Some modern hobbyists still grow dwarf citrus in containers or greenhouses in areas where it is too cold to grow it outdoors.
The genus Citrus is generally divided into two subgenera, Citrus and Papeda (Katz and Weaver 2003).
A Chinese book by Han Yen Chih, dated to 1178 C.E., mentions 27 varieties of citrus (Katz and Weaver 2003).
Some citrus has a high pectin content, which contributes to soluble fiber consumption, which in turn is linked to cardiovascular health and reduced risk of certain cancers (Katz and Weaver 2003).
Citrus plants are very liable to infestation by aphids, whitefly, and scale insects (e.g.
Many citrus fruits, such as oranges, tangerines, grapefruits, and clementines (type of mandarin), are generally eaten fresh.
Citrus was brought by the Spanish and Portuguese to to the Caribbean, from where it was introduced to North and South America.
A variety of flavors can be derived from different parts and treatments of citrus fruits.
The oldest mention of citrus traces to the Yu Kung of China, a book of tributes to the Emperor Ta Yu, who lived from about 2205 to 2197 B.C.E.
Recent research has suggested that the closely related genus Fortunella, and perhaps also Poncirus and the Australian genera Microcitrus and Eremocitrus, should be included in Citrus.
More astringent citrus, such as lemons and limes are generally not eaten on their own.
Citrus fruits are a distinctive berry with the internal parts divided into segments and include oranges, lemons, limes, citrons, grapefruit, pomelos (pummelo, pommelo), and mandarins (tangerines).