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Sweet orange+ (''Citrus × sinensis'' cultivar+)
Species+ and hybrids+
Important species:

''Citrus maxima'' – Pomelo+

''Citrus medica'' – Citron+

''Citrus micrantha'' – Papeda+

''Citrus reticulata'' – Mandarin orange+
Important hybrids:

''Citrus × aurantiifolia'' – Key lime+

''Citrus × aurantium'' – Bitter orange+

''Citrus × latifolia'' – Persian lime+

''Citrus × limon'' – Lemon+

''Citrus × limonia'' – Rangpur+

''Citrus × paradisi'' – Grapefruit+

''Citrus × sinensis'' – Sweet orange+

''Citrus × tangerina'' – Tangerine+

See also below+ for other species and hybrids.


and see text

'''''Citrus''''' is a genus+ of flowering+ trees+ and shrubs+ in the rue+ family, Rutaceae+. Plants in the genus produce '''citrus fruits''', including important crops+ like oranges+, lemon+s, grapefruit+, and limes+.

The most recent research indicates an origin in Australia+, New Caledonia+ and New Guinea+. Some researchers believe that the origin is in the part of Southeast Asia+ bordered by Northeast India+, Burma+ (Myanmar) and the Yunnan+ province of China+, and it is in this region that some commercial species such as oranges, mandarins, and lemons originated. Citrus fruit has been cultivated in an ever-widening area since ancient times.

At various times, citrus plants were thought to be native to Asia (where they were first domesticated), Europe, and Florida. But the European oranges (such as the bitter orange+) were originally brought from India at around the time of Alexander the Great+, and the "native" oranges of Florida actually originated with the Spanish+ Conquistadors+. The lemon reached Europe during the time of classical Rome+.

The generic name originated from Latin+, where it referred to either the plant now known as Citron+ (''C. medica'') or a conifer tree (''Thuja+''). It is somehow related to the ancient Greek+ word for cedar+, κέδρος (''kédros''). This may be due to perceived similarities in the smell of citrus leaves and fruit with that of cedar. Collectively, ''Citrus'' fruits and plants are also known by the Romance+ loanword+ '''agrumes''' (literally "sour fruits").

The large citrus fruit of today evolved originally from small, edible berries over millions of years. Citrus plants diverged from a common ancestor about 15 million years ago, which was about when it diverged from the closely related severinia+, for example the Chinese box orange+. About 7 million years ago, citrus plants diverged into two groups, the main citrus genus and the ancestors of the Trifoliate orange+ (poncirus), which is closely enough related that it can still be hybridized with all other citrus. These estimates are made using genetic mapping of plant chloroplast+s, and the evolution at that time is thought to either have occurred somewhere in southeastern Asia, or Australia.

The three original species in the citrus genus that have been hybridized into most modern commercial citrus fruit are the mandarin orange+, pummelo+, and citron+. Within the last few thousand years, all common citrus fruits (sweet oranges, lemons, grapefruit, limes, and so on) were created by crossing those original species. Something similar has occurred with the wide array of chili pepper+s originating in the hybridization of a few initial species.

PCA+ of SNP+ diversity).
''Citrus micrantha+'' (top right) is a papeda+.
Hybrids are expected to plot between their parents.
ML: ‘Mexican’ lime+; A: ‘Alemow+’; V: ‘Volkamer’ lemon+; M: ‘Meyer’ lemon+; L: Regular and ‘Sweet’ lemon+s; B: Bergamot orange+; H: Haploid clementine; C: Clementine+s; S: Sour orange+s; O: Sweet orange+s; G: Grapefruit+s.

The taxonomy+ and systematics+ of the genus are complex and the precise number of natural species+ is unclear, as many of the named species are hybrids+ clonally propagated through seeds (by apomixis+), and there is genetic+ evidence that even some wild, true-breeding species are of hybrid origin

Most cultivated ''Citrus'' seem to be natural+ or artificial hybrids+ of four core ancestral species — the citron+, pummelo+, mandarine+, and papeda+ (see image). Natural and cultivated citrus hybrid+s include commercially important fruit+ such as oranges+, grapefruit+, lemon+s, limes+, and some tangerine+s.

Apart from these four core citrus species, there are Australian lime+s and the recently discovered Mangshanyegan+. Kumquat+s and ''Clymenia sp.+'' are now generally considered to belong within the citrus genus. Trifoliate orange+, which is often used as commercial rootstock+, is an outgroup and may or may not be categorized as a citrus.

These plants are large shrub+s or small to moderate-sized trees, reaching The flower+s are solitary or in small corymb+s, each flower diameter, with five (rarely four) white petals and numerous stamens; they are often very strongly scented.

The fruit+ is a ''hesperidium+'', a specialised berry, globose to elongated, zest. The middle layer of the pericarp is the mesocarp, which in citrus fruits consists of the white, spongy "albedo", or "pith". The innermost layer of the pericarp is the endocarp. The segments are also called "liths+", and the space inside each lith is a locule+ filled with juice vesicles+, or "pulp". From the endocarp, string-like "hairs" extend into the locules, which provide nourishment to the fruit as it develops.

Citrus fruits are notable for their fragrance, partly due to flavonoid+s and limonoid+s (which in turn are terpene+s) contained in the rind, and most are juice-laden. The juice contains a high quantity of citric acid+ giving them their characteristic sharp flavour. The genus is commercially important as many species are cultivated for their fruit, which is eaten fresh, pressed for juice+, or preserved in marmalade+s and pickles+.

They are also good sources of vitamin C+ and flavonoids. The flavonoids include various flavanone+s and flavone+s.

Citrus trees hybridise+ very readily – depending on the pollen+ source, plants grown from a Persian lime+'s seeds can produce fruit similar to grapefruit. Thus all commercial citrus cultivation uses trees produced by grafting+ the desired fruiting cultivar+s onto rootstocks+ selected for disease resistance and hardiness.

The colour of citrus fruits only develops in climates with a (diurnal+) cool winter. In tropical regions with no winter at all, citrus fruits remain green until maturity, hence the tropical "green oranges". The Persian lime in particular is extremely sensitive to cool conditions, thus it is not usually exposed to cool enough conditions to develop a mature colour. If they are left in a cool place over winter, the fruits will change colour to yellow.

The terms "ripe" and "mature" are usually used synonymously, but they mean different things. A mature fruit is one that has completed its growth phase. Ripening+ is the changes that occur within the fruit after it is mature to the beginning of decay. These changes usually involve starches converting to sugars, a decrease in acids and a softening and change in the fruit's colour.

Citrus fruits are non-climacteric+ and respiration slowly declines and the production and release of ethylene is gradual. The fruits do not go through a ripening process in the sense that they become "tree ripe." Some fruits, for example cherries, physically mature and then continue to ripen on the tree. Other fruits, like pears, are picked when mature but before they ripen, then continue to ripen off the tree. Citrus fruits pass from immaturity to maturity to over-maturity while still on the tree. Once they are separated from the tree, they will not increase in sweetness or continue to ripen. The only way change may happen after being picked is that they will eventually start to decay.

With oranges, colour cannot be used as an indicator of ripeness because sometimes the rinds turn orange long before the oranges are ready to eat. Tasting them is the only way to know whether or not they are ready to eat.

Citrus trees are not generally frost+ hardy. Mandarin orange+s (''C. reticulata'') tend to be the hardiest of the common ''Citrus'' species and can withstand short periods down to as cold as , but realistically temperatures not falling below are required for successful cultivation. Tangerine+s, tangors and yuzu+ can be grown outside even in regions with more marked sub-freezing temperatures in winter, although this may affect fruit quality. A few hardy hybrids can withstand temperatures well below freezing, but do not produce quality fruit. Lemons can be commercially grown in cooler-summer/moderate-winter, coastal Southern California, because sweetness is neither attained nor expected in retail lemon fruit. The related trifoliate orange+ (''Citrus trifoliata'') can survive below ; its fruit are astringent and inedible unless cooked but a few better-tasting cultivars and hybrids have been developed (see citrange+s).

The trees thrive in a consistently sunny, humid environment with fertile soil and adequate rainfall or irrigation. Abandoned trees in valleys may suffer, yet survive, the dry summer of Central California's Inner Coast Range+s. At any age citrus grows well enough with infrequent irrigation in partial shade, but the fruit crop is smaller. Though broadleaved, they are evergreen and do not drop leaves except when stressed. The stems+ of many varieties have large sharp thorns+. The trees flower in the spring, and fruit is set shortly afterward. Fruit begins to ripen in fall or early winter months, depending on cultivar, and develops increasing sweetness afterward. Some cultivars of tangerines ripen by winter. Some, such as the grapefruit, may take up to eighteen months to ripen.

According to UN 2007 data, Brazil+, China+, the United States+, Mexico+, India+, and Spain+ are the world's largest citrus-producing countries.

Major commercial citrus growing areas include southern China, the Mediterranean Basin+ (including southern Spain), South Africa+, Australia+, the southernmost United States, Mexico and parts of South America+. In the United States, Florida+, California+, Arizona+, and Texas+ are major producers, while smaller plantings are present in other Sun Belt+ states and in Hawaii+.

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. An orangery+ was a feature of royal and aristocratic residences through the 17th and 18th centuries. The ''Orangerie'' at the Palace of the Louvre+, 1617, inspired imitations that were not eclipsed until the development of the modern greenhouse in the 1840s. In the United States the earliest surviving orangery is at the Tayloe House, Mount Airy, Virginia+. George Washington had an orangery at Mount Vernon+.

Some modern hobbyists still grow dwarf citrus in containers or greenhouses in areas where it is too cold to grow it outdoors. Consistent climate, sufficient sunlight, and proper watering are crucial if the trees are to thrive and produce fruit. Compared to many of the usual "green shrubs", citrus trees better tolerate poor container care. For cooler winter areas, limes+ and lemon+s should not be grown, since they are more sensitive to winter cold than other citrus fruits. Hybrids with kumquat+s (× ''Citrofortunella+'') have good cold resistance.

Citrus plants are very liable to infestation by aphid+s, whitefly+ and scale insect+s (e.g. California red scale+). Also rather important are the viral infections to which some of these ectoparasite+s serve as vectors+ such as the aphid-transmitted ''Citrus tristeza virus+'' which when unchecked by proper methods of control is devastating to citrine plantations. The newest threat to citrus groves in the United States is the Asian citrus psyllid+.

The Asian citrus psyllid is an aphid-like insect that feeds on the leaves and stems of citrus trees and other citrus-like plants – but the real danger lies in that it can carry a deadly, bacterial tree disease called , also known as citrus greening disease.

In August 2005 citrus greening disease was discovered in the south Florida region around Homestead and Florida City. It has since spread to every commercial citrus grove in Florida. In 2004-2005 USDA Ag statistics reported the total Florida citrus production to be 169.1 million boxes of fruit. The estimate for all Florida citrus production in the 2015-2016 season is 86.4 million boxes—a 51% drop.

In June 2008, the psyllid was spotted dangerously close to California – right across the international border in Tijuana+, Mexico. Only a few months later, it was detected in San Diego and Imperial counties, and has since spread to Riverside, San Bernardino, Orange, Los Angeles and Ventura counties sparking quarantines in those areas. The Asian citrus psyllid has also been intercepted coming into California in packages of fruit and plants, including citrus, ornamentals, herbs and bouquets of cut flowers, shipped from other states and countries.

The foliage is also used as a food plant by the larva+e of Lepidoptera+ (butterfly+ and moth+) species such as the Geometridae+ common emerald+ (''Hemithea aestivaria'') and double-striped pug+ (''Gymnoscelis rufifasciata''), the Arctiidae+ giant leopard moth+ (''Hypercompe scribonia''), ''H. eridanus+'', ''H. icasia+'' and ''H. indecisa+'', many species in the family Papilionidae (swallowtail butterflies), and the black-lyre leafroller moth+ (''"Cnephasia" jactatana''), a tortrix moth+.

Since 2000, the citrus leafminer+ (''Phyllocnistis citrella'') has been a pest in California, boring meandering patterns through leaves.

In eastern Australia, the bronze-orange bug+ (''Musgraveia sulciventris+'') can be a major pest of citrus trees, particularly grapefruit. In heavy infestations it can cause flower and fruit drop and general tree stress.

European brown snails (''Cornu aspersum+'') can be a problem in California, though laying female Khaki Campbell+ and other mallard+-related duck+s can be used for control.

Citrus plants can also develop a deficiency condition called chlorosis+, characterized by yellowing leavesOnline at SumoGardener highlighted by contrasting leaf vein+s. The shriveling leaves eventually fall, and if the plant loses too many, it will slowly die. This condition is often caused by an excessively high pH+ (alkaline soil+), which prevents the plant from absorbing iron+, magnesium+, zinc+, or other nutrients it needs to produce chlorophyll+. This condition can be cured by adding an appropriate acidic fertilizer formulated for citrus, which can sometimes revive a plant to produce new leaves and even flower buds within a few weeks under optimum conditions. A soil which is too acidic can also cause problems; citrus prefers neutral soil (pH between 6 and 8). Citrus plants are also sensitive to excessive salt+ in the soil. Soil testing+ may be necessary to properly diagnose nutrient deficiency diseases.

Many citrus fruits, such as oranges+, tangerine+s, grapefruit+s, and clementine+s, are generally eaten fresh. They are typically peeled and can be easily split into segments. Grapefruit is more commonly halved and eaten out of the skin with a spoon. There are special spoons (grapefruit spoon+s) with serrated tips designed for this purpose. Orange and grapefruit juices are also very popular breakfast+ beverages. More acidic citrus, such as lemon+s and limes+, are generally not eaten on their own. Meyer lemon+s can be eaten out of hand with the fragant skin; they are both sweet and sour. Lemonade+ or limeade+ are popular beverages prepared by diluting the juices of these fruits and adding sugar. Lemons and limes are also used as garnishes or in cooked dishes. Their juice is used as an ingredient in a variety of dishes; it can commonly be found in salad dressings and squeezed over cooked meat or vegetables.

A variety of flavours can be derived from different parts and treatments of citrus fruits. The rind+ and oil+ of the fruit is generally very bitter, especially when cooked, and so is often combined with sugar. The fruit pulp+ can vary from sweet and tart to extremely sour. Marmalade+, a condiment derived from cooked orange and lemon, can be especially bitter, but is usually sweetened to cut the bitterness and produce a jam-like result. Lemon or lime is commonly used as a garnish+ for water, soft drinks, or cocktails. Citrus juices, rinds, or slices are used in a variety of mixed drinks. The colourful outer skin of some citrus fruits, known as zest+, is used as a flavouring in cooking; the white inner portion of the peel, the pith, is usually avoided due to its bitterness. The zest of a citrus fruit, typically lemon or an orange, can also be soaked in water in a coffee filter+, and drunk.

Citrus fruit intake has been associated with a 10% reduction in odds of developing breast cancer.

Oranges were historically used for their high content of vitamin C+, which prevents scurvy+. Scurvy is caused by vitamin C deficiency, and can be prevented by having 10 milligrams of vitamin C a day. An early sign of scurvy is fatigue. If ignored, later symptoms are bleeding and bruising easily. British sailors were given a ration of citrus fruits on long voyages to prevent the onset of scurvy, hence the British nickname of Limey+.

Pectin+ is a structural heteropolysaccharide+ contained in the primary cell walls of plants. Limes and lemons as well as oranges and grapefruits are among the highest in this level.

After consumption, the peel is sometimes used as a facial cleanser.

Before the development of fermentation+-based processes, lemons were the primary commercial source of citric acid+.

Citrus fruit intake is associated+ with a reduced risk of stomach cancer+. Also, citrus fruit juices, such as orange, lime and lemon, may be useful for lowering the risk of specific types of kidney stone+s. Grapefruit is another fruit juice that can be used to lower blood pressure because it interferes with the metabolism of calcium channel blockers.
Lemons have the highest concentration of citrate of any citrus fruit, and daily consumption of lemonade+ has been shown to decrease the rate of kidney stone formation.

''This is a list by scientific names; there exists a list by '''common names+''' ''

The genus ''Citrus'' has been suggested to originate in Southeast Asia+. Prior to human cultivation, it consisted of just a few species, namely:
check these spp for names and assignment. Many are likely hybrids.

C. alata - C. ampullacea - C. asahikan - C. assamensis - C. aurantiaca - C. aurata - C. aurea - C. balincolong - C. balotina - C. benikoji - C. boholensis - C. canaliculata - C. celebica - C. combara - C. crenatifolia - C. daoxianensis - C. davaoensis - C. erythrosa - C. excelsa - C. flavicarpa - C. funadoko - C. genshokan - C. glaberrima - C. gracilis - C. hainanensis - C. hanaju - C. hassaku - C. hiroshimana - C. hongheensis - C. hyalopulpa - C. inflata - C. intermedia - C. iwaikan - C. karna - C. keraji - C. kerrii - C. kinokuni - C. kotokan - C. leiocarpa - C. longilimon - C. longispina - C. lycopersiciformis - C. macrolimon - C. macrophylla - C. maderaspatana - C. madurensis - C. medioglobosa - C. megaloxycarpa - C. miaray - C. micrantha - C. montana - C. nana - C. nippokoreana - C. oblonga - C. obovoidea - C. odorata - C. oleocarpa - C. otachibana - C. oto - C. panuban - C. papaya - C. papillaris - C. paratangerina - C. platymamma - C. ponki - C. pseudogulgul - C. pseudolimon - C. pseudolimonum - C. pseudopapillaris - C. pseudoparadisi - C. pseudosunki - C. pyriformis - C. rokugatsu - C. rugulosa - C. semperflorens - C. shunkokan - C. sinograndis - C. southwickii - C. suavissima - C. succosa - C. suhuiensis - C. sulcata - C. taiwanica - C. takuma-sudachi - C. tamurana - C. tankan - C. tardiferax - C. tardiva - C. tarogayo - C. temple - C. tengu - C. tumida - C. ujukitsu - C. vitiensis - C. webberi - C. westeri - C. wilsonii - C. yamabuki - C. yatsushiro - C. yuko

* ''Citrus crenatifolia+'' – species name is unresolved, from Sri Lanka+
* ''Citrus mangshanensis+'' – species name is unresolved, from Hunan Province+, China.
* ''Citrus maxima'' – Pomelo+ (pummelo, shaddock), from the Malay Archipelago+
* ''Citrus medica+'' – Citron+, from India
* ''Citrus reticulata+'' – Mandarin orange+, from China+
* ''Citrus trifoliata+'' – Trifoliate orange+, from Korea and adjacent China (often separated as ''Poncirus'')
* Australian lime+s
** ''Citrus australasica+'' – Australian Finger Lime+
** ''Citrus australis+'' – Australian Round lime+
** ''Citrus glauca+'' – Australian Desert Lime+
** ''Citrus garrawayae+ '' – Mount White Lime+
** ''Citrus gracilis+'' – Kakadu Lime or Humpty Doo Lime+
** ''Citrus inodora+'' – Russel River Lime+
** ''Citrus warburgiana+ '' – New Guinea Wild Lime+
** ''Citrus wintersii+ '' – Brown River Finger Lime+
* ''Citrus japonica+'' – Kumquat+s, from East Asia ranging into Southeast Asia (sometimes separated in 4–5 ''Fortunella'' species)
* Papedas+, including
** ''Citrus halimii+'' – ''limau kadangsa+'', ''limau kedut kera+'', from Thailand+ and Malaya+
** ''Citrus indica+'' – Indian wild orange+, from the Indian subcontinent+
** ''Citrus macroptera+'' from Indochina and Melanesia
** ''Citrus micrantha+'' from the southern Philippines
** "Khasi Papeda" – ''Citrus latipes+'' from Assam+, Meghalaya+, Burma+

Sorted by parentage. As each hybrid is the product of (at least) two parent species, they are listed multiple times.

'''''Citrus maxima''-based'''
* Amanatsu+, natsumikan – ''Citrus'' ×''natsudaidai'' (''C. maxima'' × unknown)
* Cam sành+ – (''C. reticulata'' × ''C.'' ×''sinensis'')
* Grapefruit+ – ''Citrus'' ×''paradisi'' (''C. maxima'' × ''C.'' ×''sinensis'')
* Imperial lemon+ – (''C.'' ×''limon'' × ''C.'' ×''paradisi'')
* Kinnow+ – (''C.'' ×''nobilis'' × ''C.'' ×''deliciosa'')
* Kiyomi+ – (''C.'' ×''sinensis'' × ''C.'' ×''unshiu'')
* Lemon+ – ''Citrus ×limon'' (probably ''C. maxima'' × ''C. medica'')
* Minneola tangelo+ – (''C. reticulata'' × ''C.'' ×''paradisi'')
* Orangelo+, Chironja – (''C.'' ×''paradisi'' × ''C.'' ×''sinensis'')
* Oroblanco+, Sweetie+ – (''C. maxima'' × ''C.'' ×''paradisi'')
* Sweet orange+ – ''Citrus'' ×''sinensis'' (probably ''C. maxima'' × ''C. reticulata'')
* Tangelo+ – ''Citrus'' ×''tangelo'' (''C. reticulata'' × ''C. maxima'' or ''C.'' ×''paradisi'')
* Tangor+ – ''Citrus'' ×''nobilis'' (''C. reticulata'' × ''C.'' ×''sinensis'')
* Ugli+ – (''C. reticulata'' × ''C. maxima'' or ''C.'' ×''paradisi'')

'''''Citrus medica''-based'''
* Buddha's hand+ – ''Citrus medica'' var. ''sarcodactylus'', a fingered citron.
* Citron+ varieties with sour pulp+Diamante citron+, Florentine citron+, Greek citron+ and Balady citron+
* Citron varieties with sweet pulp – Corsican citron+ and Moroccan citron+.
* Etrog+, a group of citron cultivars that are traditionally used for a Jewish ritual. ''Etrog'' is Hebrew+ for citron in general.
* Fernandina+ – ''Citrus'' ×''limonimedica'' (probably (''C. medica'' × ''C. maxima'') × ''C. medica'')
* Ponderosa lemon+ – (probably (''C. medica'' × ''C. maxima'') × ''C. medica'')
* Lemon+ – ''Citrus ×limon'' (probably ''C. medica'' × ''C. maxima'')
* Key lime+, Mexican lime, Omani lime - ''Citrus'' ×''aurantiifolia'' (''C. medica'' × ''C. micrantha'')
* Lumia+ - a pear shaped lemon hybrid, (probably ''C. medica'' x ''C. limon)
* Rhobs el Arsa+ - bread of the garden, a Moroccan+ citron x lemon hybrid.
* Yemenite citron+ – a pulpless true citron.

'''''Citrus reticulata''-based'''
* Bergamot orange+ – ''Citrus'' ×''bergamia'' (''C. limetta'' × ''C.'' ×''aurantium'')
* Bitter orange+, Seville Orange – ''Citrus'' ×''aurantium'' (''C. maxima'' × ''C. reticulata'')
* Blood orange+ – ''Citrus'' ×''sinensis'' cultivar+s
* Calamondin+, Calamansi – (''Citrus reticulata'' × ''Citrus japonica'')
* Cam sành+ – (''C. reticulata'' × ''C.'' ×''sinensis'')
* Chinotto+ – ''Citrus'' ×''aurantium'' var. ''myrtifolia'' or ''Citrus'' ×''myrtifolia''
* ChungGyun+ – ''Citrus reticulata'' cultivar
* Clementine+ – ''Citrus'' ×''clementina''
* Cleopatra Mandarin+ – ''Citrus'' ×''reshni''
* Siranui+ – ''Citrus reticulata'' cv. 'Dekopon' (ChungGyun × Ponkan)
* Daidai+ – ''Citrus'' ×''aurantium'' var. ''daidai'' or ''Citrus'' ×''daidai''
* Grapefruit+ – ''Citrus'' ×''paradisi'' (''C. maxima'' × ''C.'' ×''sinensis'')
* Hermandina+ – ''Citrus reticulata'' cv. 'Hermandina'
* Imperial lemon+ – ((''C. maxima'' × ''C. medica'') × ''C.'' ×''paradisi'')
* Kinnow+, Wilking – (''C.'' ×''nobilis'' × ''C.'' ×''deliciosa'')
* Kiyomi+ – (''C. sinensis'' × ''C.'' ×''unshiu'')
* Laraha+ – ''''C.'' ×''aurantium'' ssp. ''currassuviencis''
* Mediterranean mandarin+, Willow Leaf+ – ''Citrus'' ×''deliciosa''
* Meyer lemon+, Valley Lemon – ''Citrus'' ×''meyeri'' ((''C. maxima'' × ''C. medica'') × ''C.'' ×''paradisi'' or ''C.'' ×''sinensis'')
* Michal mandarin+ – ''Citrus reticulata'' cv. 'Michal'
* Mikan+, Satsuma – ''Citrus'' ×''unshiu''
* Naartjie+ – (''C. reticulata'' × ''C. nobilis'')
* Nova mandarin+, Clemenvilla+
* Orangelo+, Chironja+ – (''C.'' ×''paradisi'' × ''C.'' ×''sinensis'')
* Oroblanco+, Sweetie+ – (''C. maxima'' × ''C.'' ×''paradisi'')
* Ponkan+ – ''Citrus reticulata'' cv. 'Ponkan'
* Rangpur+, Lemanderin, Mandarin Lime – ''Citrus'' ×''limonia'' ((''C. reticulata'' × ''C. maxima'') × ''C. medica'')
* Sweet orange+ – ''Citrus'' ×''sinensis'' (probably ''C. maxima'' × ''C. reticulata'')
* Tangelo+ – ''Citrus'' ×''tangelo'' (''C. reticulata'' × ''C. maxima'' or ''C.'' ×''paradisi'')
* Tangerine+ – ''Citrus'' ×''tangerina''
* Tangor+ – ''Citrus'' ×''nobilis'' (''C. reticulata'' × ''C.'' ×''sinensis'')
* Ugli+ – (''C. reticulata'' × ''C. maxima'' or ''C.'' ×''paradisi'')
* Yuzu+ – ''Citrus'' ×''junos'' (''C. reticulata'' × ''C.'' ×''ichangensis'')
* Alemow+, Colo – ''Citrus'' ×''macrophylla''
* Djeruk limau+ – ''Citrus'' ×''amblycarpa''
* Gajanimma+, Carabao Lime+ – ''Citrus'' ×''pennivesiculata''
* Hyuganatsu+, Hyuganatsu pumelo – ''Citrus tamurana''
* Ichang lemon+, Ichang Papeda – ''Citrus'' ×''ichangensis''
* Imperial lemon+ – (''C.'' ×''limon × C.'' ×''paradisi'')
* Iyokan+, ''anadomikan'' – ''Citrus'' ×''iyo''
* Kabosu+ – ''Citrus'' ×''sphaerocarpa''
* Kaffir lime+, ''makrut'' – ''Citrus'' ×''hystrix''
* Limetta+, Sweet Lemon, Sweet Lime, mosambi – ''Citrus'' ×''limetta''
* – ''Citrus'' ×''limettioides'' Tanaka+
* Odichukuthi+ – ''Citrus Odichukuthi'' from Malayalam
* Ougonkan+ – ''Citrus flaviculpus'' hort ex.Tanaka
* Persian lime+, Tahiti Lime – ''Citrus'' ×''latifolia''
* Pompia+ – ''Citrus monstruosa'', a ''nomen nudum+''
* Rough lemon+ – ''Citrus'' ×''jambhiri'' Lush.
* Sakurajima komikan orange+
* Shekwasha+, Hirami Lemon, Taiwan Tangerine – ''Citrus'' ×''depressa''
* Shonan gold+ – (Ougonkan) ''Citrus flaviculpus'' hort ex. Tanaka × (Imamura unshiu), ''Citrus unshiu'' Marc
* Sudachi+ – ''Citrus'' ×''sudachi''
* Sunki+, Suenkat+ – ''Citrus'' ×''sunki''
* Tachibana orange+ – ''Citrus'' ×''tachibana'' (Mak.) Tanaka+
* Volkamer lemon+ – ''Citrus'' ×''volkameriana''

For hybrids with kumquat+s, see ×''Citrofortunella''+. For hybrids with the Trifoliate Orange+, see citrange+.

The Moroccan professor Henri Chapot discovered that the acidity in the more common citrons or lemon+s is represented by red on the inner coat of seeds specifically on the chalaza+l spot, violet pigmentation on the outer side of the flower blossom, and also by the new buds that are reddish-purplish. The acidless varieties of citrus are completely lacking the red color in all the mentioned spots. This designation was

* Japanese citrus+
* List of lemon dishes and beverages+

* (2002): ''Citrus''. Taylor and Francis. ISBN 0-415-28491-0
* (1985): Chapter 64. Rutaceae. ''In: Handbook of Seed Technology for Genebanks'' (Volume II: Compendium of Specific Germination Information and Test Recommendations). International Board for Plant Genetic Resources, Rome, Italy.
* (1991): ''FAO/IBPGR Technical Guidelines for the Safe Movement of Citrus Germplasm''. FAO, IOCV, IPGRI.
* (1999): Descriptors for Citrus (''Citrus spp.'').
* (2005): Purdue University+ Tropical Horticulture Lecture 32:
* (1995): RFLP analysis of cytoplasmic and nuclear genomes used for citrus taxonomy. ''In: Mandarines – développements scientifiques récents, résumés oraux et posters'': 12–13. CIRAD-FLHOR, San Nicolao, France.
* (2000): ''Citrus, Proceedings of a regional workshop on disease management of banana and citrus through the use of disease-free planting materials held in Davao City, Philippines, 14–16 October 1998''. INIBAP.
* (2005): ''Orange Empire: California and the Fruits of Eden''.
* (1967–1989): ''The Citrus Industry''.

* EOL:
* Pollination of Citrus by Honey Bees
* of IFAS+ (largest citrus research center in world)
* (Mark Rieger, Professor of Horticulture, University of Georgia)
* is an organization of citrus Brazil+ian producers and processors.
* fruit anatomy+ at GeoChemBio
* Season of Maturity • Seeds / Fruit Information • Fruit Size • Fruit and Tree Insight
* The history of citrus by Enrique García Ballesteros


Citrus+ Citrus is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops like oranges, lemons, grapefruit, and limes.
Citric acid+ Citric acid is a weak organic tricarboxylic acid having the chemical formula C6H8O7. It occurs naturally in citrus fruits.
 Citrus Connection+ Citrus Connection is the public transit system of Lakeland, Florida, operated by the Lakeland Area Mass Transit District (LAMTD).
Citrus County, Florida+ Citrus County is a county located in the U.S. state of Florida. As of the 2010 census, the population was 141,236. Its county seat is Inverness, and its largest community is Homosassa Springs.
 Citrus Bowl+ The Citrus Bowl, also known as the Buffalo Wild Wings Citrus Bowl for sponsorship purposes, is an annual college football bowl game played at Camping World Stadium in Orlando, Florida.
Citrullus colocynthis+ Citrullus colocynthis, with many common names including colocynth, bitter apple, bitter cucumber, desert gourd, egusi, vine of Sodom, or wild gourd, is a desert viny plant native to the Mediterranean Basin and Asia, especially Turkey (especially in regions such as İzmir), Nubia, and Trieste.
Citrus taxonomy+ Citrus taxonomy refers to the botanical classification of the species, varieties, cultivars, and graft hybrids within the genus Citrus, subgenus Papeda, and related genera, found in cultivation and in the wild.
CitrusTV+ CitrusTV is the completely student-run television studio of Syracuse University and the State University of New York College of Environmental Science and Forestry in Syracuse, New York.
Citrus unshiu+ Citrus unshiu is a seedless and easy-peeling citrus species, also known as unshu mikan, cold hardy mandarin, satsuma mandarin, satsuma orange, Christmas orange, and tangerine.
Citrus black spot+ Citrus Black Spot is a fungal disease caused by Guignardia citricarpa. This Ascomycete fungus affects citrus plants throughout subtropical climates, causing a reduction in both fruit quantity and quality.