Longan: Difference between revisions
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{{Short description|Species of tropical fruit-bearing tree}} |
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{{about|the fruit and tree|other uses|Long'an (disambiguation)}} |
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{{About|the fruit and tree|other uses|Long'an (disambiguation)|places in China|Longnan|and|Longyan}} |
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{{distinguish|Loganberry}} |
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{{Distinguish|Loganberry}} |
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{{speciesbox |
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{{Use dmy dates|date=August 2021}} |
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{{Speciesbox |
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|name = Longan |
|name = Longan |
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|image = Longan tree at Pine Island Nursery.jpg |
|image = Longan tree at Pine Island Nursery.jpg |
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|image_alt = Photograph of a broadly spreading tree |
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|image2 = Dimocarpus_longan_fruits.jpg |
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|status = DD |
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|image2_caption = Longan fruit |
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|status_system = IUCN3.1 |
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|status = LR/nt |
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|status_ref =<ref name=IUCN>{{cite iucn | author = Barstow, M. | title = ''Dimocarpus longan'' | page = e.T32399A67808402 | year = 2022 | access-date = 29 January 2023}}</ref> |
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|status_system = IUCN2.3 |
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|status_ref = <ref name=IUCN>{{cite journal | title = ''Dimocarpus longan'' | journal = [[IUCN Red List of Threatened Species]] | volume= 1998 | page = e.T32399A9698234 | publisher = [[IUCN]] | year = 1998 | url = http://www.iucnredlist.org/details/32399/0 | doi = 10.2305/IUCN.UK.1998.RLTS.T32399A9698234.en | accessdate = 5 Sep 2016}}</ref> |
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|genus = Dimocarpus |
|genus = Dimocarpus |
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|species = longan |
|species = longan |
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|authority = [[João de Loureiro|Lour.]]<ref name=TPL>{{ThePlantList | |
|authority = [[João de Loureiro|Lour.]]<ref name=TPL>{{ThePlantList | access-date=5 September 2016}}</ref> |
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|synonyms = |
|synonyms = |
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{{Plainlist | style = margin-left: 1em; text-indent: -1em; | |
{{Plainlist | style = margin-left: 1em; text-indent: -1em; | |
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*''Dimocarpus undulatus'' <small>Wight</small> |
*''Dimocarpus undulatus'' <small>Wight</small> |
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*''Euphoria cinerea'' <small>(Turcz.) Radlk.</small> |
*''Euphoria cinerea'' <small>(Turcz.) Radlk.</small> |
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*''Dimocarpus leichhardtii''<small>S.T. Reynolds</small> |
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*''Euphoria glabra'' <small>Blume</small> |
*''Euphoria glabra'' <small>Blume</small> |
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*''Euphoria gracilis'' <small>Radlk.</small> |
*''Euphoria gracilis'' <small>Radlk.</small> |
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*''Nephelium longana'' <small>Cambess.</small> |
*''Nephelium longana'' <small>Cambess.</small> |
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}} |
}} |
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|synonyms_ref = |
|synonyms_ref =<ref name=TPL/> |
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}} |
}} |
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{{Infobox Chinese |
{{Infobox Chinese |
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|p=lóngyǎn |
|p=lóngyǎn |
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|w=lung<sup>2</sup>-yen<sup>3</sup> |
|w=lung<sup>2</sup>-yen<sup>3</sup> |
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|bpmf=ㄌㄨㄥˊ ㄧㄢˇ |
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|mi={{IPAc-cmn|l|ong|2|.|yan|3}} |
|mi={{IPAc-cmn|l|ong|2|.|yan|3}} |
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|suz=lón-ngê |
|suz=lón-ngê |
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|ci={{IPAc-yue|l|ung|4|.|ng|aan|5}} |
|ci={{IPAc-yue|l|ung|4|.|ng|aan|5}} |
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|poj=lêng-géng |
|poj=lêng-géng |
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|tl=lîng-gíng |
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|l="dragon eye" |
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|l='dragon eye' |
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}} |
}} |
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'''''Dimocarpus longan''''', commonly known as the '''longan''' ( |
'''''Dimocarpus longan''''', commonly known as the '''longan''' ({{IPAc-en|ˈ|l|ɒ|ŋ|a:|n|}}) and '''dragon's eye''', is a tropical tree species that produces edible fruit.<ref name="Julia Morton">{{Cite book|title=Longan; In: Fruits of Warm Climates|last=Morton|first=Julia F.|publisher=NewCrop, Center for New Crops and Plant Products, Department of Horticulture and Landscape Architecture, Purdue University|year=1987|location=W. Lafayette, IN, USA|pages=259–262|url=https://hort.purdue.edu/newcrop/morton/longan.html}}</ref> It is one of the better-known tropical members of the soapberry family [[Sapindaceae]], to which the [[lychee]] and [[rambutan]] also belong.<ref name="Julia Morton" /> The fruit of the longan is similar to that of the lychee, but is less aromatic in taste.<ref name="Fruiting pattern">{{Cite journal|last1=Pham|first1=V.T.|last2=Herrero|first2=M.|title=Fruiting pattern in longan, Dimocarpus longan: from pollination to aril development|journal=Annals of Applied Biology|volume=169|issue=3|pages=357–368|doi=10.1111/aab.12306|year=2016|hdl=10261/135703|url=https://digital.csic.es/bitstream/10261/135703/1/HormazaI_AnnApplBiol_2016.pdf|hdl-access=free}}</ref> |
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The longan (from [[Vietnamese language|Vietnamese]] ''long nhãn''<ref name="Lour1790">{{cite book|last=Loureiro|first=J. de|year=1790|title=Flora Cochinchinensis|volume=I|location=Lisbon|publisher=Ulyssipone|url=https://www.biodiversitylibrary.org/item/192210#page/259/mode/1up|language=la}}</ref> or [[Cantonese]] ''lùhng ngáahn'' {{lang|zh|龍眼}}, literally 'dragon eye'), is so named because the black seed within the shelled fruit creates the appearance of an eyeball. The plant is native to tropical Asia and China.<ref>{{GRIN|access-date=11 December 2017}}</ref> |
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The longan (from [[Cantonese]] ''lùhng-ngáahn'' {{lang|zh|龍眼}}, literally "dragon eye"), is so named because it resembles an eyeball when its fruit is shelled (the black seed shows through the translucent flesh like a pupil/iris). The seed is small, round and hard, and of an enamel-like, lacquered black. The fully ripened, freshly harvested fruit has a bark-like shell, thin, and firm, making the fruit easy to peel by squeezing the pulp out as if one is "cracking" a sunflower seed. When the shell has more moisture content and is more tender, the fruit becomes less convenient to shell. The tenderness of the shell varies due to either premature harvest, variety, weather conditions, or transport/storage conditions. |
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== |
== Description == |
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Depending upon climate and soil type the tree may grow to over {{Convert|100|ft|m}}<ref>{{cite web | |
Depending upon climate and soil type the tree may grow to over {{Convert|100|ft|m|order=flip}}<ref>{{cite web |last1=Crane |first1=Jonathan H. |last2=Balerdi |first2=Carlos F. |last3=Sargent |first3=Steven A. |last4=Maguire |first4=Ian |date=November 1978 |title=Longan Growing in the Florida Home Landscape |url=http://edis.ifas.ufl.edu/mg049 |access-date=4 April 2017 |website=University of Florida |edition=2016}}</ref> in height, but it typically stands {{Convert|30|-|40|ft|0|abbr=on|order=flip}} in height and the [[Crown (botany)|crown]] is round.<ref name="Julia Morton" /><ref name="Crane Balerdi">{{cite web |last1=Crane |first1=Jonathan |last2=Balerdi |first2=Carlos |last3=Sarge |first3=Steven |last4=Maguire |first4=Ian |date=2015 |title=Longan Growing in the Florida Home Landscape |url=http://www.edis.ifas.ufl.edu/mg049 |access-date=5 April 2017 |website=IFAS University of Florida}}</ref> The trunk is {{Convert|80|cm|ft|abbr=on|frac=2}} thick<ref name="Julia Morton" /> with corky [[bark (botany)|bark]].<ref name="Crane Balerdi" /> The branches are long and thick, typically drooping.<ref name="Julia Morton" /> |
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The [[ |
The [[leaves]] are oblong and blunt-tipped, usually {{Convert|4|-|8|in|cm|0|order=flip}} long and {{Convert|2|in|cm|0|abbr=on|order=flip}} wide.<ref name="Julia Morton" /> The leaves are [[pinnately]] compounded and alternate.<ref name="Crane Balerdi" /> There are 6 to 9 pairs of leaflets per leaf<ref name="Crane Balerdi" /> and the upper surface is wavy and a dark, glossy-green.<ref name="Julia Morton" /> |
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The |
The longan tree produces light-yellow [[inflorescence]]s at the end of branches.<ref name="Julia Morton" /> The inflorescence is commonly called a [[panicle]]; they can be {{Convert|4|-|18|in|cm|abbr=on|order=flip}} long, and widely branched.<ref name="Crane Balerdi" /> The small [[flower]]s have 5 to 6 [[sepal]]s and [[petal]]s that are brownish-yellow.<ref name="Crane Balerdi" /> The flower has a two-lobed [[pistil]] and 8 [[stamen]]. There are three flower types, distributed throughout the panicle;<ref name="Julia Morton" /> staminate (functionally male), pistillate (functionally female), and [[Hermaphrodite|hermaphroditic]] flowers.<ref name="Crane Balerdi" /> Flowering occurs as a progression.<ref name="Crane Balerdi" /> |
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[[File:Frutos Exóticos-LONGAN.jpg|thumb|Longan fruit with flesh, seed, and peel visible.]] |
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The fruit hangs in drooping clusters that are circular and about {{Convert|1|in|cm|1|abbr=on}} wide. The peel is tan, thin, and leathery with tiny hairs.<ref name="Crane Balerdi" /> The flesh is translucent, and the [[seed]] is large and black with a circular white spot at the base.<ref name="Julia Morton" /><ref name="Crane Balerdi" /> This gives the illusion of an eye.<ref name="Julia Morton" /> The flesh has a musky, sweet taste, which can be compared to the flavor of lychee fruit.<ref name="Julia Morton" /> |
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The fruit are circular and about {{Convert|1|in|cm|1|abbr=on|order=flip}} wide; they hang in drooping clusters. The shell is tan, thin, and leathery with tiny hairs;<ref name="Crane Balerdi" /> when firm, it can be squeezed (as in the cracking of a [[sunflower seed]]) to shell the fruit.{{Citation needed|date=August 2024}} The flesh is translucent, and the [[seed]] is large and black with a circular white spot at the base.<ref name="Julia Morton" /><ref name="Crane Balerdi" /> This gives the illusion of an eye.<ref name="Julia Morton" /> The flesh has a musky, sweet taste, which can be compared to the flavor of [[lychee]] fruit.<ref name="Julia Morton" /> The seed is round, hard, and has a lacquered appearance.{{Citation needed|date=August 2024}} |
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The Longan tree is somewhat sensitive to [[frost]]. Longan trees prefer sandy soil. While the species prefers temperatures that do not typically fall below {{Convert|4.5|C|F|-1}}, it can withstand brief temperature drops to about {{Convert|-2|C|F}}.<ref>{{Cite book|title=The Deluxe Food Lover's Companion|last=Herbst|first=S. & R.|publisher=Barron's Educational Series|year=2009|isbn=|location=|pages=|quote=|via=Credo Reference}}</ref> Longans usually bear fruit slightly later than lychees.<ref>{{Cite journal|last=Jiang|first=Yueming|last2=Zhang|first2=Zhaoqi|date=November 2002|title=Postharvest biology and handling of longan fruit (Dimocarpus longan Lour.)|journal=Postharvest Biology and Technology|volume=26|issue=3|pages=241–252|doi=10.1016/s0925-5214(02)00047-9}}</ref> |
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The longan tree is somewhat sensitive to [[frost]]. While the species prefers temperatures that do not typically fall below {{Convert|4.5|C|F|-1}}, it can withstand brief temperature drops to about {{Convert|-2|C|F}}.<ref>{{Cite book |last=Herbst |first=S. & R. |title=The Deluxe Food Lover's Companion |publisher=Barron's Educational Series |year=2009 |via=Credo Reference}}</ref> Longan trees prefer sandy soil with mild levels of acidity and [[Soil#Soil organic matter|organic matter]].<ref name="Julia Morton" /> Longans usually bear fruit slightly later than lychees.<ref>{{Cite journal |last1=Jiang |first1=Yueming |last2=Zhang |first2=Zhaoqi |date=November 2002 |title=Postharvest biology and handling of longan fruit (Dimocarpus longan Lour.) |journal=Postharvest Biology and Technology |volume=26 |issue=3 |pages=241–252 |doi=10.1016/s0925-5214(02)00047-9}}</ref> |
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[[File:Longan Wiki1.webm|thumb|left|Video of longan being peeled and eaten.]] |
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{{gallery|mode=packed |
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The wild longan population have been decimated considerably by large-scale loggings in the past, and the species used to be listed as [[Vulnerable species|Vulnerable]] on the [[IUCN Red List]]. If left alone, longan tree stumps will resprout and the listing was upgraded to [[Near Threatened]] in 1998. Recent field data are inadequate for a contemporary IUCN assessment.<ref name=IUCN/> |
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|Longan (Dimocarpus longan) Tree lower trunk.jpg|Lower trunk |
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|Longan (Dimocarpus longan) Tree leaves.jpg|Tree leaves |
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|Longan (Dimocarpus longan) baby fruits and leaves.jpg|Branch of baby fruits |
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|Dimocarpus_longan_fruits.jpg|Bunch of fruit |
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|Frutos Exóticos-LONGAN.jpg|Fruit with flesh, seed, and peel visible |
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|Longan Wiki1.webm|Longan being peeled and eaten |
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}} |
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== |
==Taxonomy== |
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The longan is believed to originate from the mountain range between [[Myanmar]] and southern China. Other reported origins include [[India]], [[Sri Lanka]], upper Myanmar, north Thailand, [[Cambodia|Kampuchea]] (more commonly known as Cambodia), north [[Vietnam]] and [[New Guinea]].<ref name="TK Lim">{{Cite book|title=Edible Medicinal And Non-Medicinal Plants: Volume 6, Fruits|last=Lim|first=T.K.|publisher=Springer Science & Business Media|year=2013|isbn=|location=|pages=|quote=|via=Google Books}}</ref> |
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The longan is believed to originate from the mountain range between [[Myanmar]] and southern China. Other reported origins include Indonesia, India, [[Sri Lanka]], [[upper Myanmar]], north Thailand, [[Kampuchea]] (more commonly known as Cambodia), north [[Vietnam]] and [[New Guinea]].<ref name="TK Lim">{{Cite book |title=Edible Medicinal And Non-Medicinal Plants: Volume 6, Fruits |last=Lim |first=T.K. |chapter=Dimocarpus longan subsp. longan var. longan|publisher=Springer Science & Business Media |year=2013 |isbn=978-94-007-5628-1 |pages=18–29}}</ref> |
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Its earliest record of existence draws back to the [[Han dynasty|Han Dynasty]] in 200 BC. The emperor had demanded lychee and longan trees to be planted in his palace gardens in [[Shaanxi]], but the plants failed. Fortunately, four hundred years later, longan trees flourished in other parts of China like [[Fujian]] and [[Guangdong]], where longan production soon became an industry.<ref name="BPU">{{Cite book|title=Litchi and Longan: Botany, Production and Uses| last=Menzel| first=C.|last2=Waite |first2=G.K. |last3=Mitra |first3=S.K.|publisher=CAB International| year=2005| isbn=9781845930226| location=|pages=|quote=|via=ProQuest ebrary}}</ref> |
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Its earliest record of existence draws back to the [[Han dynasty]] in 200 [[BCE]]. The emperor had demanded lychee and longan trees to be planted in his palace gardens in [[Shaanxi]], but the plants failed. Four hundred years later, longan trees flourished in other parts of China like [[Fujian]] and [[Guangdong]], where longan production soon became an industry.<ref name="BPU">{{Cite book|title=Litchi and Longan: Botany, Production and Uses| last1=Menzel| first1=C.|last2=Waite |first2=G.K. |last3=Mitra |first3=S.K. |publisher=CAB International| year=2005| isbn=9781845930226|via=ProQuest ebrary}}</ref> |
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Later on, due to immigration and the growing demand for nostalgic foods, the longan tree was officially introduced to Australia in the mid-1800s, Thailand in the late-1800s, and Hawaii and Florida in the 1900s. The warm, sandy-soiled conditions allowed for the easy growth of longan trees. This jump-started the longan industry in these locations.<ref name="BPU"/> |
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Later on, due to immigration and the growing demand for nostalgic foods, the longan tree was officially introduced to Australia in the mid-1800s, Thailand in the late-1800s, and Hawaii and Florida in the 1900s. The warm, sandy-soiled conditions allowed for the easy growth of longan trees. This jump-started the longan industry in these locations.<ref name="BPU" /> |
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Despite its long success in China, the longan is considered to be a relatively new fruit to the world. It has only been acknowledged outside of China recently in the last 250 years.<ref name="BPU"/> The first European acknowledgement of the fruit was recorded by [[João de Loureiro|Joao de Loureiro]], a Jesuit botanist, in 1790. The first entry resides in his collection of works, ''Flora Cochinchinensis''.<ref name="Fruiting pattern"/> |
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Despite its long success in China, the longan is considered to be a relatively new fruit to the world. It has only been acknowledged outside of China in the last 250 years.<ref name="BPU" /> The first European acknowledgment of the fruit was recorded by [[João de Loureiro]], a Portuguese Jesuit botanist, in 1790. The first entry resides in his collection of works, ''Flora Cochinchinensis''.<ref name="Lour1790" /><ref name="Fruiting pattern" /> |
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[[File:Flora_Cochinchinensis,_t._1.jpg|thumb|222x222px|The longan was described in Joao de Loureiro's work, ''Flora Cochinchinensis'', published in 1790.]] |
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=== Subspecies === |
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Currently, longan crops are grown in southern China, Taiwan, northern Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam, India, Sri Lanka, [[Philippines]], Australia, U.S., and [[Mauritius]].<ref name="TK Lim" /> |
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[[Plants of the World Online]] lists:<ref>{{cite web |title=Dimocarpus longan Lour. | Plants of the World Online | Kew Science |url=http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:782795-1 |website=Plants of the World Online}}</ref> |
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* ''D. longan'' var. ''echinatus'' Leenhouts (Borneo, Philippines) |
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* ''D. longan'' var. ''longetiolatus'' Leenhouts (Viet Nam) |
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* ''D. longan'' subsp. ''malesianus'' Leenh. (widespread SE Asia) |
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* ''D. longan'' var. ''obtusus'' (Pierre) Leenh. (Indo-China) |
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== Conservation == |
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==Culinary uses== |
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The wild longan population have been decimated considerably by large-scale logging in the past, and the species used to be listed as [[Vulnerable species|Vulnerable]] on the [[IUCN Red List]]. If left alone, longan tree stumps will resprout and the listing was upgraded to [[Near Threatened]] in 1998. Recent field data are inadequate for a contemporary IUCN assessment.<ref name="IUCN" /> |
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The fruit is sweet, juicy and succulent in superior agricultural varieties. The seed and the shell are not consumed. Apart from being eaten fresh and raw, longan fruit is also often used in Asian soups, snacks, desserts, and [[sweet-and-sour]] foods, either fresh or dried, and sometimes preserved and canned in syrup. The taste is different from lychees; while longan have a drier sweetness, lychees are often messily juicy with a more tropical, sour sweetness. |
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== Diseases == |
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Dried longan are often used in [[Chinese cuisine]] and Chinese sweet dessert soups. In [[Chinese food therapy]] and [[Chinese medicine|herbal medicine]], it is believed to have an effect on relaxation.<ref>{{cite web|last1=Teeguarden|first1=Ron|title=Tonic Herbs That Every Qigong Practioner<nowiki>[sic]</nowiki> Should Know, Part 2|url=https://www.qi-journal.com/herbs.asp?Name=Tonic%20Herbs%20that%20Every%20Qigong%20Practitoners%20Should%20Know%20--Part%202&-token.D=Article|website=Qi Journal}}</ref> In contrast with the fresh fruit, which is juicy and white, the flesh of dried longans is dark brown to almost black. |
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Plant based diseases can affect both longan fruits and their trees, and the severity of these diseases can range from harmless cosmetic damage to rendering to the fruit inedible. |
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The most prevalent disease among longan plants is [[witch's broom]], which can be found in all major longan-producing Asian territories, including China, Thailand, and Vietnam.<ref>{{Cite journal |last1=Olesen |first1=T. |last2=Menzel |first2=C. M. |last3=Wiltshire |first3=N. |last4=McConchie |first4=C. A. |date=2002 |title=Flowering and shoot elongation of lychee in eastern Australia |url=http://dx.doi.org/10.1071/ar01179 |journal=Australian Journal of Agricultural Research |volume=53 |issue=8 |pages=977 |doi=10.1071/ar01179 |issn=0004-9409}}</ref> Witch's broom deforms longan skin, and at times causes the plant to prematurely drop its fruit, similar to the ''[[Phytophthora palmivora]]''.<ref>{{Cite journal |last1=So |first1=Vera |last2=Zee |first2=S.-Y. |date=September 1972 |title=A New Virus of Longan (''Euphoria longana'' Lam.) in Hong Kong |url=http://dx.doi.org/10.1080/09670877209411804 |journal=PANS Pest Articles & News Summaries |volume=18 |issue=3 |pages=283–285 |doi=10.1080/09670877209411804 |issn=0030-7793}}</ref> |
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== Folk medicine == |
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{{nutritional value | name=Longans, raw |
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Another common disease that longan trees can carry is the aptly named ''longan decline'', which is largely prevalent in Thailand, with reports finding that it could affect up to 40% of longan trees alone.<ref name=":0">{{Cite book |url=http://dx.doi.org/10.1079/9780851996967.0000 |title=Litchi and longan: botany, production and uses |date=2005 |isbn=9780851996967 |editor-last=Menzel |editor-first=C. M. |doi=10.1079/9780851996967.0000 |editor2-last=Waite |editor2-first=G. K.}}</ref> Affected trees are more vulnerable to common tree pests and algae, and often bear low-quality fruit unworthy of yield.<ref name=":0" /> |
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| image=Frutos Exóticos-LonganFruit-002.JPG |
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| caption = A peeled longan fruit |
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''Algal spot'' is another plant disease that can affect longan plants and trees. Common among tropical fruits, the disease mainly takes form as red-orange algae that can appear on a fruit-bearing tree's leaves or branches.<ref>{{Cite journal |last=Visarathanonth |first=N. |date=December 1990 |title=A Survey of Some Temperate Fruit Diseases in Thailand |url=http://dx.doi.org/10.17660/actahortic.1990.279.67 |journal=Acta Horticulturae |issue=279 |pages=609–618 |doi=10.17660/actahortic.1990.279.67 |issn=0567-7572}}</ref>''Algal spot'' on longan plants, like many other tropical fruits, is caused by ''[[Cephaleuros virescens]]''.<ref>{{Cite journal |last=Bache |first=Bryon |date=December 1994 |title=Compendium of Tropical Fruit Diseases, by R. C. Ploetz G. A. Zentmyer, W. T. Nishijima, K. G. Rohrbach & H. D. Ohr. viii + 88 pp. St Paul, Minnesota: American Phytopathological Society (1994). £30.00 (US) $37.00 (elsewhere) (paper back) {{text|ISBN}} 0 582 89054 162 0. |url=http://dx.doi.org/10.1017/s0021859600070520 |journal=The Journal of Agricultural Science |volume=123 |issue=3 |pages=419–420 |doi=10.1017/s0021859600070520 |issn=0021-8596}}</ref> |
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| kJ=251 |
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| protein=1.31 g |
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An oomycete disease that causes [[blight]] on leaves and foliage of a plant and affects the related lychee, ''Phytophthora palmivora'', can also appear on both longan plants and fruit,<ref name="Wang-et-al-20192">{{cite journal |last1=Wang |first1=Yan |last2=Tyler |first2=Brett M. |last3=Wang |first3=Yuanchao |date=2019-09-08 |title=Defense and Counterdefense During Plant-Pathogenic Oomycete Infection |journal=[[Annual Review of Microbiology]] |publisher=[[Annual Reviews (publisher)|Annual Reviews]] |volume=73 |issue=1 |pages=667–696 |doi=10.1146/annurev-micro-020518-120022 |issn=0066-4227 |pmid=31226025 |s2cid=195259901}}</ref> particularly in the Thailand region. When affecting longan, it can create brown spots on the fruit in an erratic fashion, and can also cause longan to drop prematurely from the plant. Early symptoms can also include a dark [[necrosis]] on the plant itself.<ref>{{Cite journal |last1=Sittigul |first1=C. |last2=Pota |first2=S. |last3=Visitpanich |first3=J. |last4=Nualbunruang |first4=P. |last5=Sookchaoy |first5=K. |date=January 2005 |title=The Brown Spot Disease of Longan in Thailand |url=http://dx.doi.org/10.17660/actahortic.2005.665.48 |journal=Acta Horticulturae |issue=665 |pages=389–394 |doi=10.17660/actahortic.2005.665.48 |issn=0567-7572}}</ref> |
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| fat=0.1 g |
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| carbs=15.14 g |
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Stem-end rot is a disease common amongst litchi and longan, and causes browning and rot on the stem of the fruit. Longan also suffer from various decay-accelerating fungi.<ref name=":0" /> |
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| fiber=1.1 g |
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| sugars=n/a |
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An oomycete disease that affects the related lychee, ''[[Phytophthora litchii]]'', also afflicts ''D. longan''.<ref name="Wang-et-al-20192" /> |
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| calcium_mg=1 |
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| iron_mg=0.13 |
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==Cultivation== |
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| magnesium_mg=10 |
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| phosphorus_mg=21 |
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Currently, longan crops are grown in southern China, [[Taiwan]], northern Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam, India, Sri Lanka, the [[Philippines]],<ref name="TK Lim" /> [[Bangladesh]],<ref name="KhatunKarim2012">{{cite journal |last1=Khatun |first1=MM |last2=Karim |first2=MR |last3=Molla |first3=MM |last4=Khatun |first4=MM |last5=Rahman |first5=MJ |year=2012 |title=Study on the physico-chemical characteristics of longan (Euphoria longana) germplasm |journal=Bangladesh Journal of Agricultural Research |volume=37 |issue=3 |pages=441–447 |doi=10.3329/bjar.v37i3.12087 |issn=0258-7122 |doi-access=free}}</ref> [[Mauritius]], the United States, and Australia.<ref name="TK Lim" /> |
|||
| potassium_mg=266 |
|||
| sodium_mg=0 |
|||
=== Growth === |
|||
| zinc_mg=0.05 |
|||
Longan, like its sister fruit lychee, thrives in humid areas or places with high rainfall, and can grow on most types of soil that does not induce issues with water drainage.<ref name=":1">{{Cite book |url=http://dx.doi.org/10.1079/9781845936723.0000 |title=Tropical fruits, Volume 1 |date=2011 |isbn=9781845936723 |editor-last=Paull |editor-first=R. E. |doi=10.1079/9781845936723.0000 |editor2-last=Duarte |editor2-first=O.}}</ref> Ample temperatures are also instrumental in longan growth: while longan can resist small stretches of cool temperatures, they can be damaged or killed in longer stretches of temperatures as high as −2 degrees Celsius. Younger plants tend to be more vulnerable to the cold than those more mature.<ref name=":1" /><ref>{{Cite book |last=Blancke |first=Rolf |url=http://dx.doi.org/10.7591/9781501704284 |title=Tropical Fruits and Other Edible Plants of the World |date=2017-03-17 |isbn=9781501704284 |doi=10.7591/9781501704284}}</ref> |
|||
| manganese_mg=0.052 |
|||
| vitC_mg=84 |
|||
{{nutritional value |
|||
| thiamin_mg=0.031 |
|||
| name = Longans, raw |
|||
| riboflavin_mg=0.14 |
|||
| image = Frutos Exóticos-LonganFruit-002.JPG |
|||
| niacin_mg=0.3 |
|||
| caption = A peeled longan fruit |
|||
<!-- amino acids --> |
|||
| kJ = 251 |
|||
| threonine=0.034 g |
|||
| |
| water = 83 g |
||
| |
| protein = 1.31 g |
||
| |
| fat = 0.1 g |
||
| |
| carbs = 15.14 g |
||
| |
| fiber = 1.1 g |
||
| sugars = n/a |
|||
| tyrosine=0.025 g |
|||
| calcium_mg = 1 |
|||
| valine=0.058 g |
|||
| |
| iron_mg = 0.13 |
||
| magnesium_mg = 10 |
|||
| histidine=0.012 g |
|||
| phosphorus_mg = 21 |
|||
| alanine=0.157 g |
|||
| potassium_mg = 266 |
|||
| aspartic acid=0.126 g |
|||
| |
| sodium_mg = 0 |
||
| |
| zinc_mg = 0.05 |
||
| |
| manganese_mg = 0.052 |
||
| |
| vitC_mg = 84 |
||
| thiamin_mg = 0.031 |
|||
| riboflavin_mg = 0.14 |
|||
| niacin_mg = 0.3 |
|||
<!-- amino acids -->| threonine = 0.034 g |
|||
| isoleucine = 0.026 g |
|||
| leucine = 0.054 g |
|||
| lysine = 0.046 g |
|||
| methionine = 0.013 g |
|||
| phenylalanine = 0.030 g |
|||
| tyrosine = 0.025 g |
|||
| valine = 0.058 g |
|||
| arginine = 0.035 g |
|||
| histidine = 0.012 g |
|||
| alanine = 0.157 g |
|||
| aspartic acid = 0.126 g |
|||
| glutamic acid = 0.209 g |
|||
| glycine = 0.042 g |
|||
| proline = 0.042 g |
|||
| serine = 0.048 g |
|||
| source_usda = 1 |
| source_usda = 1 |
||
| note=[ |
| note = [https://fdc.nal.usda.gov/fdc-app.html#/food-details/169089/nutrients Link to USDA Database entry]<br/> |
||
}} |
|||
}}Longan is commonly found in traditional Eastern folk medicine as opposed to modern Western medicine. This is not an unusual occurrence since, prior to the 1800s, longan was most prevalent in Asia.<ref name="BPU"/> |
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=== Harvest === |
|||
During harvest, pickers must climb ladders to carefully remove branches of fruit from longan trees. Longan fruit remain fresher if still attached to the branch, so efforts are made to prevent the fruit from detaching too early. Mechanical picking would damage the delicate skin of the fruit, so the preferred method is to harvest by hand. Knives and scissors are the most commonly used tools.<ref name="Muhammad Siddiq2">{{Cite book |last=Siddiq |first=Muhammad |title=Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging |publisher=John Wiley & Sons |year=2012 |via=Google Books}}</ref> |
|||
Fruit is picked early in the day to minimize water loss and to prevent high heat exposure, which would be damaging. The fruit is then placed into either plastic crates or bamboo baskets and taken to packaging houses, where the fruit undergo a series of checks for quality. The packaging houses are well-ventilated and shaded to prevent further decay. The process of checking and sorting are performed by workers instead of machinery. Any fruit that is split, under-ripe, or decaying is disposed of. The remaining healthy fruit is then prepared and shipped to markets.<ref name="BPU2">{{Cite book |last1=Menzel |first1=C. |title=Litchi and Longan: Botany, Production and Uses |last2=Waite |first2=G.K. |last3=Mitra |first3=S.K. |publisher=CAB International |year=2005 |isbn=9781845930226 |via=ProQuest ebrary}}</ref> |
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In ancient Vietnamese medicine, the "eye" of the longan seed is pressed against snakebites to absorb the venom. This was ineffective, but is still commonly used today.<ref>{{Cite book|title=Top 100 Exotic Food Plants|last=Small|first=Ernest|publisher=CRC Press|year=2011|via=Google Books}}</ref> |
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Many companies add preservatives to canned longan. Regulations control the preserving process. The only known preservative added to canned longan is [[sulfur dioxide]], to prevent discoloration.<ref name="BPU2" /> Fresh longan that is shipped worldwide is exposed to sulfur [[fumigation]]. Tests have shown that sulfur residues remain on the fruit skin, branches, and leaves for a few weeks. This violates many countries' limits on fumigation residue, and efforts have been made to reduce this amount.<ref name="BPU2" /> |
|||
==Cultivation, harvest and distribution== |
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It is found commonly in most of Asia, primarily in China, Taiwan, Vietnam and Thailand.<ref name="Antioxidant">{{Cite journal|title=Antioxidant and Anti-Inflammatory Properties of Longan (Dimocarpus longan Lour.) Pericarp|url=https://www.hindawi.com/journals/ecam/2012/709483/|journal=Evidence-Based Complementary and Alternative Medicine|volume=2012}}</ref> China, the main longan-producing country in the world, produced about 1,300 million [[tonne]]s of longan in 2010. Vietnam and Thailand had produced around 600 million and 500 million tonnes, respectively.<ref name="Fruiting pattern"/> Like Vietnam, Thailand's economy relies heavily on the cultivation and shipments of longan as well as lychee. This increase in the production of longan reflects recent interest in exotic fruits in other parts of the world. However, the majority of the demand comes from Asian communities in North America, Europe and Australia.<ref name="BPU"/> |
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=== Distribution === |
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The longan industry is very new in North America and Australia. Commercial crops have only been around for twenty years. In Florida, the small quantity produced are sold only at local farmer's markets. In Australia, the crops are much bigger, stretching along the northern and eastern coasts. The weather is much better suited for longan growth.<ref name="BPU" /> |
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Longan is found commonly in most of Asia, primarily in mainland China, Taiwan, Vietnam and Thailand. China, the main longan-producing country in the world, produced about {{convert|1.9|e6MT|e6ST|abbr=off}} of longan in 2015–2017, accounting for 70% of the world's longan production and more than 50% of the world's longan plots.<ref>Luo, Jun, Can-fang Zhou, and Zhong Wan. "Analysis on the development status of lychee industry in Guangdong province in 2010." Guangdong Agric Sci 4 (2011): 16-8.</ref> Vietnam and Thailand produced around {{convert|500 and 980|e3MT|e3ST|abbr=off}}, respectively.<ref>{{cite web |last=Altendorf |first=Sabine |date=July 2018 |title=MINOR TROPICAL FRUITS Mainstreaming a niche market |url=http://www.fao.org/fileadmin/templates/est/COMM_MARKETS_MONITORING/Tropical_Fruits/Documents/Minor_Tropical_Fruits_FoodOutlook_1_2018.pdf |access-date=9 September 2020 |publisher=[[FAO]]}}</ref> Like Vietnam, Thailand's economy relies heavily on the cultivation and shipments of longan as well as lychee. This increase in the production of longan reflects recent interest in exotic fruits in other parts of the world. However, the majority of the demand comes from Asian communities in North America, Europe and Australia.<ref name="BPU2" /> |
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===Yield === |
|||
During harvest, pickers must climb ladders to carefully remove branches of fruit from longan trees. It has been found that longan fruit remain fresher when still attached to the branch, so efforts are made to prevent the fruit from detaching too early. Mechanical picking would damage the delicate skin of the fruit, so the preferred method is to harvest by hand. Knives and scissors are the most commonly used tools.<ref name="Muhammad Siddiq">{{Cite book|title=Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging|last=Siddiq|first=Muhammad|publisher=John Wiley & Sons|year=2012|via=Google Books}}</ref> |
|||
While longan yields average out to 2 to 5 tonnes per hectare, there have been observed yields of up to 19.5 tonnes per ha in [[Israel]].<ref>{{Citation |last1=Lora |first1=Jorge |title=Genetics and Breeding of Fruit Crops in the Sapindaceae Family: Lychee (Litchi chinensis Sonn.) and Longan (Dimocarpus longan Lour.) |date=2018 |work=Advances in Plant Breeding Strategies: Fruits |pages=953–973 |editor-last=Al-Khayri |editor-first=Jameel M. |url=http://link.springer.com/10.1007/978-3-319-91944-7_23 |access-date=2022-10-05 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-91944-7_23 |isbn=978-3-319-91943-0 |last2=Pham |first2=Van The |last3=Hormaza |first3=José I. |editor2-last=Jain |editor2-first=Shri Mohan |editor3-last=Johnson |editor3-first=Dennis V.}}</ref> |
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Advancements in [[selective breeding]] have allowed scientists to find a strain of longan containing a "high proportion of aborted seeds" at the end of a thirty-year breeding program in 2001.<ref>{{Cite journal |last1=Huang |first1=J.S. |last2=Xu |first2=X.D. |last3=Zheng |first3=S.Q. |last4=Xu |first4=J.H. |date=August 2001 |title=Selection for Aborted-Seeded Longan Cultivars |url=http://dx.doi.org/10.17660/actahortic.2001.558.14 |journal=Acta Horticulturae |issue=558 |pages=115–118 |doi=10.17660/actahortic.2001.558.14 |issn=0567-7572}}</ref> Studies in 2015 that aimed to aid longan breeding efforts discovered that −20 degrees Celsius is the optimal temperature for long-term storage of longan pollen, a key ingredient in enabling longan breeding programs.<ref>{{Cite journal |last1=Pham |first1=V.T. |last2=Herrero |first2=M. |last3=Hormaza |first3=J.I. |date=December 2015 |title=Effect of temperature on pollen germination and pollen tube growth in longan ( Dimocarpus longan Lour.) |url=http://dx.doi.org/10.1016/j.scienta.2015.10.007 |journal=Scientia Horticulturae |volume=197 |pages=470–475 |doi=10.1016/j.scienta.2015.10.007 |bibcode=2015ScHor.197..470P |issn=0304-4238 |hdl-access=free |hdl=10261/127752}}</ref> |
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It is also encouraged to pick the fruit earlier in the day in order to "minimize water loss" as well as prevent high heat exposure, which would be damaging. The fruit is then carefully placed into either plastic crates or bamboo baskets and taken to packaging houses, where the fruit undergo a series of checks for standards. The packaging houses are well-ventilated and shaded to prevent further decay. The process of checking and sorting are performed by workers instead of machinery. Any fruit that are split, under ripe, or decaying are disposed of. The remaining healthy fruit are then prepped and shipped to markets.<ref name="BPU" /> |
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== Uses == |
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In terms of distribution, many companies add preservatives and chemicals to canned longan. These chemicals have been popularly known to, though not yet officially proven, cause unpleasant sensations such as burning lips, tingling of the mouth and tongue, and poor digestion. Due to these discoveries, more regulations have been made to control the preserving process. So far, the only known chemical added to canned longan is [[sulfur dioxide]] to prevent discoloration. There have been no studies to ascertain whether it has harmful effects on consumers.<ref name="BPU" /> |
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=== Nutrition === |
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Use of chemicals is not limited only to canned longan. Fresh longan that is shipped worldwide is exposed to sulfur [[fumigation]]. Tests have shown that sulfur residues remain on the fruit skin, branches, and leaves for a few weeks. This violates many countries' limits on fumigation residue, but efforts have been made to reduce this amount.<ref name="BPU" /> |
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Raw longan fruit is 83% water, 15% [[carbohydrate]]s, 1% [[protein (nutrient)|protein]], and contains negligible [[fat]] (table). In a {{cvt|100|g}} reference amount, raw longan supplies 60 [[calorie]]s of food energy, 93% of the [[Daily Value]] (DV) of [[vitamin C]], 11% DV of [[riboflavin]], and no other [[micronutrient]]s in appreciable quantities (table). |
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=== Culinary === |
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[[Potassium chlorate]] has been found to cause the longan tree to blossom. However, this causes stress on the tree if it is used excessively, and eventually kills it. |
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The fruit is sweet, juicy, and succulent in superior agricultural varieties. The seed and the peel are not consumed. Apart from being eaten raw like other fruits, longan fruit is also often used in Asian soups, snacks, desserts, and [[sweet-and-sour]] foods, either fresh or dried, and sometimes preserved and canned in syrup. The taste is different from lychees; while longan has a drier sweetness similar to dates, lychees are often messily juicy with a more tropical, grape-like sour sweetness. |
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Dried longan are often used in [[Chinese cuisine]] and Chinese sweet dessert soups. In [[Chinese food therapy]] and [[Chinese medicine|herbal medicine]], it is believed to have an effect on relaxation.<ref>{{cite web|last1=Teeguarden|first1=Ron|title=Tonic Herbs That Every Qigong {{sic|Pract|ioner|nolink=y|expected=Practitioner}} Should Know, Part 2|url=https://www.qi-journal.com/herbs.asp?Name=Tonic%20Herbs%20that%20Every%20Qigong%20Practitoners%20Should%20Know%20--Part%202&-token.D=Article|website=Qi Journal|access-date=4 August 2016|archive-date=4 July 2019|archive-url=https://web.archive.org/web/20190704121122/http://www.qi-journal.com/herbs.asp?Name=Tonic%20Herbs%20that%20Every%20Qigong%20Practitoners%20Should%20Know%20--Part%202&-token.D=Article|url-status=dead}}</ref> In contrast with the fresh fruit, which is juicy and white, the flesh of dried longans is dark brown to almost black. |
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Once fermented, it can be made into [[longan wine]]. |
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==See also== |
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*''[[Lansium parasiticum]]'', the langsat or lanzones |
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*''[[Talisia esculenta]]'', a visually similar fruit from South America |
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==References== |
==References== |
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{{ |
{{Reflist}} |
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==External links== |
==External links== |
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{{Commons category|Dimocarpus longan|''Dimocarpus longan''}} |
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* [http://www.hort.purdue.edu/newcrop/morton/longan.html Fruits of Warm Climates: Longan] |
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{{Wikispecies|Dimocarpus longan|''Dimocarpus longan''}} |
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* [http://www.fao.org/DOCREP/003/X6908E/x6908e00.htm#Contents Longan Production in Asia] from the [[Food and Agriculture Organization|Food and Agriculture Organization of the United Nations]] |
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* [http://www.fao.org/DOCREP/003/X6908E/x6908e00.htm#Contents Longan Production in Asia] from the [[Food and Agriculture Organization]] of the United Nations |
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{{Taxonbar}} |
{{Taxonbar|from=Q193449}} |
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{{Authority control}} |
{{Authority control}} |
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[[Category:Articles containing video clips]] |
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[[Category:Cantonese cuisine]] |
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[[Category:Chinese fruit]] |
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[[Category:Dimocarpus|longan]] |
[[Category:Dimocarpus|longan]] |
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[[Category:Trees of Bangladesh]] |
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[[Category:Trees of China]] |
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[[Category:Trees of India]] |
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[[Category:Trees of Indo-China]] |
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[[Category:Trees of Malesia]] |
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[[Category:Indomalaya ecozone flora]] |
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[[Category:Edible fruits]] |
[[Category:Edible fruits]] |
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[[Category:Flora of tropical Asia]] |
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[[Category:Fruits originating in East Asia]] |
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[[Category:Han dynasty]] |
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[[Category:Indomalayan realm flora]] |
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[[Category:Plants described in 1790]] |
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[[Category:Traditional Chinese medicine]] |
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[[Category:Trees of China]] |
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[[Category:Tropical fruit]] |
[[Category:Tropical fruit]] |
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[[Category:Fruits originating in Asia]] |
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[[Category:Cambodian cuisine]] |
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[[Category:Malaysian cuisine]] |
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[[Category:Vietnamese cuisine]] |
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[[Category:Near threatened plants]] |
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[[Category:Edible Sapindaceae]] |
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[[Category:Articles containing video clips]] |
Latest revision as of 21:46, 22 December 2024
Longan | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Sapindales |
Family: | Sapindaceae |
Genus: | Dimocarpus |
Species: | D. longan
|
Binomial name | |
Dimocarpus longan | |
Synonyms[2] | |
|
Longan | |||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Traditional Chinese | 龍眼 | ||||||||||||||||||||||||||||||
Simplified Chinese | 龙眼 | ||||||||||||||||||||||||||||||
Literal meaning | 'dragon eye' | ||||||||||||||||||||||||||||||
|
Dimocarpus longan, commonly known as the longan (/ˈlɒŋɑːn/) and dragon's eye, is a tropical tree species that produces edible fruit.[3] It is one of the better-known tropical members of the soapberry family Sapindaceae, to which the lychee and rambutan also belong.[3] The fruit of the longan is similar to that of the lychee, but is less aromatic in taste.[4]
The longan (from Vietnamese long nhãn[5] or Cantonese lùhng ngáahn 龍眼, literally 'dragon eye'), is so named because the black seed within the shelled fruit creates the appearance of an eyeball. The plant is native to tropical Asia and China.[6]
Description
[edit]Depending upon climate and soil type the tree may grow to over 30 metres (100 ft)[7] in height, but it typically stands 9–12 m (30–40 ft) in height and the crown is round.[3][8] The trunk is 80 cm (2+1⁄2 ft) thick[3] with corky bark.[8] The branches are long and thick, typically drooping.[3]
The leaves are oblong and blunt-tipped, usually 10–20 centimetres (4–8 in) long and 5 cm (2 in) wide.[3] The leaves are pinnately compounded and alternate.[8] There are 6 to 9 pairs of leaflets per leaf[8] and the upper surface is wavy and a dark, glossy-green.[3]
The longan tree produces light-yellow inflorescences at the end of branches.[3] The inflorescence is commonly called a panicle; they can be 10–46 cm (4–18 in) long, and widely branched.[8] The small flowers have 5 to 6 sepals and petals that are brownish-yellow.[8] The flower has a two-lobed pistil and 8 stamen. There are three flower types, distributed throughout the panicle;[3] staminate (functionally male), pistillate (functionally female), and hermaphroditic flowers.[8] Flowering occurs as a progression.[8]
The fruit are circular and about 2.5 cm (1 in) wide; they hang in drooping clusters. The shell is tan, thin, and leathery with tiny hairs;[8] when firm, it can be squeezed (as in the cracking of a sunflower seed) to shell the fruit.[citation needed] The flesh is translucent, and the seed is large and black with a circular white spot at the base.[3][8] This gives the illusion of an eye.[3] The flesh has a musky, sweet taste, which can be compared to the flavor of lychee fruit.[3] The seed is round, hard, and has a lacquered appearance.[citation needed]
The longan tree is somewhat sensitive to frost. While the species prefers temperatures that do not typically fall below 4.5 °C (40 °F), it can withstand brief temperature drops to about −2 °C (28 °F).[9] Longan trees prefer sandy soil with mild levels of acidity and organic matter.[3] Longans usually bear fruit slightly later than lychees.[10]
Taxonomy
[edit]The longan is believed to originate from the mountain range between Myanmar and southern China. Other reported origins include Indonesia, India, Sri Lanka, upper Myanmar, north Thailand, Kampuchea (more commonly known as Cambodia), north Vietnam and New Guinea.[11]
Its earliest record of existence draws back to the Han dynasty in 200 BCE. The emperor had demanded lychee and longan trees to be planted in his palace gardens in Shaanxi, but the plants failed. Four hundred years later, longan trees flourished in other parts of China like Fujian and Guangdong, where longan production soon became an industry.[12]
Later on, due to immigration and the growing demand for nostalgic foods, the longan tree was officially introduced to Australia in the mid-1800s, Thailand in the late-1800s, and Hawaii and Florida in the 1900s. The warm, sandy-soiled conditions allowed for the easy growth of longan trees. This jump-started the longan industry in these locations.[12]
Despite its long success in China, the longan is considered to be a relatively new fruit to the world. It has only been acknowledged outside of China in the last 250 years.[12] The first European acknowledgment of the fruit was recorded by João de Loureiro, a Portuguese Jesuit botanist, in 1790. The first entry resides in his collection of works, Flora Cochinchinensis.[5][4]
Subspecies
[edit]Plants of the World Online lists:[13]
- D. longan var. echinatus Leenhouts (Borneo, Philippines)
- D. longan var. longetiolatus Leenhouts (Viet Nam)
- D. longan subsp. malesianus Leenh. (widespread SE Asia)
- D. longan var. obtusus (Pierre) Leenh. (Indo-China)
Conservation
[edit]The wild longan population have been decimated considerably by large-scale logging in the past, and the species used to be listed as Vulnerable on the IUCN Red List. If left alone, longan tree stumps will resprout and the listing was upgraded to Near Threatened in 1998. Recent field data are inadequate for a contemporary IUCN assessment.[1]
Diseases
[edit]Plant based diseases can affect both longan fruits and their trees, and the severity of these diseases can range from harmless cosmetic damage to rendering to the fruit inedible.
The most prevalent disease among longan plants is witch's broom, which can be found in all major longan-producing Asian territories, including China, Thailand, and Vietnam.[14] Witch's broom deforms longan skin, and at times causes the plant to prematurely drop its fruit, similar to the Phytophthora palmivora.[15]
Another common disease that longan trees can carry is the aptly named longan decline, which is largely prevalent in Thailand, with reports finding that it could affect up to 40% of longan trees alone.[16] Affected trees are more vulnerable to common tree pests and algae, and often bear low-quality fruit unworthy of yield.[16]
Algal spot is another plant disease that can affect longan plants and trees. Common among tropical fruits, the disease mainly takes form as red-orange algae that can appear on a fruit-bearing tree's leaves or branches.[17]Algal spot on longan plants, like many other tropical fruits, is caused by Cephaleuros virescens.[18]
An oomycete disease that causes blight on leaves and foliage of a plant and affects the related lychee, Phytophthora palmivora, can also appear on both longan plants and fruit,[19] particularly in the Thailand region. When affecting longan, it can create brown spots on the fruit in an erratic fashion, and can also cause longan to drop prematurely from the plant. Early symptoms can also include a dark necrosis on the plant itself.[20]
Stem-end rot is a disease common amongst litchi and longan, and causes browning and rot on the stem of the fruit. Longan also suffer from various decay-accelerating fungi.[16]
An oomycete disease that affects the related lychee, Phytophthora litchii, also afflicts D. longan.[19]
Cultivation
[edit]Currently, longan crops are grown in southern China, Taiwan, northern Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam, India, Sri Lanka, the Philippines,[11] Bangladesh,[21] Mauritius, the United States, and Australia.[11]
Growth
[edit]Longan, like its sister fruit lychee, thrives in humid areas or places with high rainfall, and can grow on most types of soil that does not induce issues with water drainage.[22] Ample temperatures are also instrumental in longan growth: while longan can resist small stretches of cool temperatures, they can be damaged or killed in longer stretches of temperatures as high as −2 degrees Celsius. Younger plants tend to be more vulnerable to the cold than those more mature.[22][23]
Nutritional value per 100 g (3.5 oz) | |||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Energy | 251 kJ (60 kcal) | ||||||||||||||||||||||||||||||||||||
15.14 g | |||||||||||||||||||||||||||||||||||||
Sugars | n/a | ||||||||||||||||||||||||||||||||||||
Dietary fiber | 1.1 g | ||||||||||||||||||||||||||||||||||||
0.1 g | |||||||||||||||||||||||||||||||||||||
1.31 g | |||||||||||||||||||||||||||||||||||||
Threonine | 0.034 g | ||||||||||||||||||||||||||||||||||||
Isoleucine | 0.026 g | ||||||||||||||||||||||||||||||||||||
Leucine | 0.054 g | ||||||||||||||||||||||||||||||||||||
Lysine | 0.046 g | ||||||||||||||||||||||||||||||||||||
Methionine | 0.013 g | ||||||||||||||||||||||||||||||||||||
Phenylalanine | 0.030 g | ||||||||||||||||||||||||||||||||||||
Tyrosine | 0.025 g | ||||||||||||||||||||||||||||||||||||
Valine | 0.058 g | ||||||||||||||||||||||||||||||||||||
Arginine | 0.035 g | ||||||||||||||||||||||||||||||||||||
Histidine | 0.012 g | ||||||||||||||||||||||||||||||||||||
Alanine | 0.157 g | ||||||||||||||||||||||||||||||||||||
Aspartic acid | 0.126 g | ||||||||||||||||||||||||||||||||||||
Glutamic acid | 0.209 g | ||||||||||||||||||||||||||||||||||||
Glycine | 0.042 g | ||||||||||||||||||||||||||||||||||||
Proline | 0.042 g | ||||||||||||||||||||||||||||||||||||
Serine | 0.048 g | ||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||
Other constituents | Quantity | ||||||||||||||||||||||||||||||||||||
Water | 83 g | ||||||||||||||||||||||||||||||||||||
†Percentages estimated using US recommendations for adults,[24] except for potassium, which is estimated based on expert recommendation from the National Academies.[25] |
Harvest
[edit]During harvest, pickers must climb ladders to carefully remove branches of fruit from longan trees. Longan fruit remain fresher if still attached to the branch, so efforts are made to prevent the fruit from detaching too early. Mechanical picking would damage the delicate skin of the fruit, so the preferred method is to harvest by hand. Knives and scissors are the most commonly used tools.[26]
Fruit is picked early in the day to minimize water loss and to prevent high heat exposure, which would be damaging. The fruit is then placed into either plastic crates or bamboo baskets and taken to packaging houses, where the fruit undergo a series of checks for quality. The packaging houses are well-ventilated and shaded to prevent further decay. The process of checking and sorting are performed by workers instead of machinery. Any fruit that is split, under-ripe, or decaying is disposed of. The remaining healthy fruit is then prepared and shipped to markets.[27]
Many companies add preservatives to canned longan. Regulations control the preserving process. The only known preservative added to canned longan is sulfur dioxide, to prevent discoloration.[27] Fresh longan that is shipped worldwide is exposed to sulfur fumigation. Tests have shown that sulfur residues remain on the fruit skin, branches, and leaves for a few weeks. This violates many countries' limits on fumigation residue, and efforts have been made to reduce this amount.[27]
Distribution
[edit]Longan is found commonly in most of Asia, primarily in mainland China, Taiwan, Vietnam and Thailand. China, the main longan-producing country in the world, produced about 1.9 million metric tons (2.1 million short tons) of longan in 2015–2017, accounting for 70% of the world's longan production and more than 50% of the world's longan plots.[28] Vietnam and Thailand produced around 500 and 980 thousand metric tons (550 and 1,080 thousand short tons), respectively.[29] Like Vietnam, Thailand's economy relies heavily on the cultivation and shipments of longan as well as lychee. This increase in the production of longan reflects recent interest in exotic fruits in other parts of the world. However, the majority of the demand comes from Asian communities in North America, Europe and Australia.[27]
Yield
[edit]While longan yields average out to 2 to 5 tonnes per hectare, there have been observed yields of up to 19.5 tonnes per ha in Israel.[30]
Advancements in selective breeding have allowed scientists to find a strain of longan containing a "high proportion of aborted seeds" at the end of a thirty-year breeding program in 2001.[31] Studies in 2015 that aimed to aid longan breeding efforts discovered that −20 degrees Celsius is the optimal temperature for long-term storage of longan pollen, a key ingredient in enabling longan breeding programs.[32]
Uses
[edit]Nutrition
[edit]Raw longan fruit is 83% water, 15% carbohydrates, 1% protein, and contains negligible fat (table). In a 100 g (3.5 oz) reference amount, raw longan supplies 60 calories of food energy, 93% of the Daily Value (DV) of vitamin C, 11% DV of riboflavin, and no other micronutrients in appreciable quantities (table).
Culinary
[edit]The fruit is sweet, juicy, and succulent in superior agricultural varieties. The seed and the peel are not consumed. Apart from being eaten raw like other fruits, longan fruit is also often used in Asian soups, snacks, desserts, and sweet-and-sour foods, either fresh or dried, and sometimes preserved and canned in syrup. The taste is different from lychees; while longan has a drier sweetness similar to dates, lychees are often messily juicy with a more tropical, grape-like sour sweetness.
Dried longan are often used in Chinese cuisine and Chinese sweet dessert soups. In Chinese food therapy and herbal medicine, it is believed to have an effect on relaxation.[33] In contrast with the fresh fruit, which is juicy and white, the flesh of dried longans is dark brown to almost black.
Once fermented, it can be made into longan wine.
See also
[edit]- Lansium parasiticum, the langsat or lanzones
- Talisia esculenta, a visually similar fruit from South America
References
[edit]- ^ a b Barstow, M. (2022). "Dimocarpus longan". IUCN Red List of Threatened Species. 2022: e.T32399A67808402. Retrieved 29 January 2023.
- ^ a b "Dimocarpus longan". World Checklist of Selected Plant Families. Royal Botanic Gardens, Kew. Retrieved 5 September 2016 – via The Plant List. Note that this website has been superseded by World Flora Online
- ^ a b c d e f g h i j k l m Morton, Julia F. (1987). Longan; In: Fruits of Warm Climates. W. Lafayette, IN, USA: NewCrop, Center for New Crops and Plant Products, Department of Horticulture and Landscape Architecture, Purdue University. pp. 259–262.
- ^ a b Pham, V.T.; Herrero, M. (2016). "Fruiting pattern in longan, Dimocarpus longan: from pollination to aril development" (PDF). Annals of Applied Biology. 169 (3): 357–368. doi:10.1111/aab.12306. hdl:10261/135703.
- ^ a b Loureiro, J. de (1790). Flora Cochinchinensis (in Latin). Vol. I. Lisbon: Ulyssipone.
- ^ "Dimocarpus longan". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 11 December 2017.
- ^ Crane, Jonathan H.; Balerdi, Carlos F.; Sargent, Steven A.; Maguire, Ian (November 1978). "Longan Growing in the Florida Home Landscape". University of Florida (2016 ed.). Retrieved 4 April 2017.
- ^ a b c d e f g h i j Crane, Jonathan; Balerdi, Carlos; Sarge, Steven; Maguire, Ian (2015). "Longan Growing in the Florida Home Landscape". IFAS University of Florida. Retrieved 5 April 2017.
- ^ Herbst, S. & R. (2009). The Deluxe Food Lover's Companion. Barron's Educational Series – via Credo Reference.
- ^ Jiang, Yueming; Zhang, Zhaoqi (November 2002). "Postharvest biology and handling of longan fruit (Dimocarpus longan Lour.)". Postharvest Biology and Technology. 26 (3): 241–252. doi:10.1016/s0925-5214(02)00047-9.
- ^ a b c Lim, T.K. (2013). "Dimocarpus longan subsp. longan var. longan". Edible Medicinal And Non-Medicinal Plants: Volume 6, Fruits. Springer Science & Business Media. pp. 18–29. ISBN 978-94-007-5628-1.
- ^ a b c Menzel, C.; Waite, G.K.; Mitra, S.K. (2005). Litchi and Longan: Botany, Production and Uses. CAB International. ISBN 9781845930226 – via ProQuest ebrary.
- ^ "Dimocarpus longan Lour. | Plants of the World Online | Kew Science". Plants of the World Online.
- ^ Olesen, T.; Menzel, C. M.; Wiltshire, N.; McConchie, C. A. (2002). "Flowering and shoot elongation of lychee in eastern Australia". Australian Journal of Agricultural Research. 53 (8): 977. doi:10.1071/ar01179. ISSN 0004-9409.
- ^ So, Vera; Zee, S.-Y. (September 1972). "A New Virus of Longan (Euphoria longana Lam.) in Hong Kong". PANS Pest Articles & News Summaries. 18 (3): 283–285. doi:10.1080/09670877209411804. ISSN 0030-7793.
- ^ a b c Menzel, C. M.; Waite, G. K., eds. (2005). Litchi and longan: botany, production and uses. doi:10.1079/9780851996967.0000. ISBN 9780851996967.
- ^ Visarathanonth, N. (December 1990). "A Survey of Some Temperate Fruit Diseases in Thailand". Acta Horticulturae (279): 609–618. doi:10.17660/actahortic.1990.279.67. ISSN 0567-7572.
- ^ Bache, Bryon (December 1994). "Compendium of Tropical Fruit Diseases, by R. C. Ploetz G. A. Zentmyer, W. T. Nishijima, K. G. Rohrbach & H. D. Ohr. viii + 88 pp. St Paul, Minnesota: American Phytopathological Society (1994). £30.00 (US) $37.00 (elsewhere) (paper back) ISBN 0 582 89054 162 0". The Journal of Agricultural Science. 123 (3): 419–420. doi:10.1017/s0021859600070520. ISSN 0021-8596.
- ^ a b Wang, Yan; Tyler, Brett M.; Wang, Yuanchao (8 September 2019). "Defense and Counterdefense During Plant-Pathogenic Oomycete Infection". Annual Review of Microbiology. 73 (1). Annual Reviews: 667–696. doi:10.1146/annurev-micro-020518-120022. ISSN 0066-4227. PMID 31226025. S2CID 195259901.
- ^ Sittigul, C.; Pota, S.; Visitpanich, J.; Nualbunruang, P.; Sookchaoy, K. (January 2005). "The Brown Spot Disease of Longan in Thailand". Acta Horticulturae (665): 389–394. doi:10.17660/actahortic.2005.665.48. ISSN 0567-7572.
- ^ Khatun, MM; Karim, MR; Molla, MM; Khatun, MM; Rahman, MJ (2012). "Study on the physico-chemical characteristics of longan (Euphoria longana) germplasm". Bangladesh Journal of Agricultural Research. 37 (3): 441–447. doi:10.3329/bjar.v37i3.12087. ISSN 0258-7122.
- ^ a b Paull, R. E.; Duarte, O., eds. (2011). Tropical fruits, Volume 1. doi:10.1079/9781845936723.0000. ISBN 9781845936723.
- ^ Blancke, Rolf (17 March 2017). Tropical Fruits and Other Edible Plants of the World. doi:10.7591/9781501704284. ISBN 9781501704284.
- ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on 27 March 2024. Retrieved 28 March 2024.
- ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). "Chapter 4: Potassium: Dietary Reference Intakes for Adequacy". In Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). pp. 120–121. doi:10.17226/25353. ISBN 978-0-309-48834-1. PMID 30844154. Retrieved 5 December 2024.
- ^ Siddiq, Muhammad (2012). Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging. John Wiley & Sons – via Google Books.
- ^ a b c d Menzel, C.; Waite, G.K.; Mitra, S.K. (2005). Litchi and Longan: Botany, Production and Uses. CAB International. ISBN 9781845930226 – via ProQuest ebrary.
- ^ Luo, Jun, Can-fang Zhou, and Zhong Wan. "Analysis on the development status of lychee industry in Guangdong province in 2010." Guangdong Agric Sci 4 (2011): 16-8.
- ^ Altendorf, Sabine (July 2018). "MINOR TROPICAL FRUITS Mainstreaming a niche market" (PDF). FAO. Retrieved 9 September 2020.
- ^ Lora, Jorge; Pham, Van The; Hormaza, José I. (2018), Al-Khayri, Jameel M.; Jain, Shri Mohan; Johnson, Dennis V. (eds.), "Genetics and Breeding of Fruit Crops in the Sapindaceae Family: Lychee (Litchi chinensis Sonn.) and Longan (Dimocarpus longan Lour.)", Advances in Plant Breeding Strategies: Fruits, Cham: Springer International Publishing, pp. 953–973, doi:10.1007/978-3-319-91944-7_23, ISBN 978-3-319-91943-0, retrieved 5 October 2022
- ^ Huang, J.S.; Xu, X.D.; Zheng, S.Q.; Xu, J.H. (August 2001). "Selection for Aborted-Seeded Longan Cultivars". Acta Horticulturae (558): 115–118. doi:10.17660/actahortic.2001.558.14. ISSN 0567-7572.
- ^ Pham, V.T.; Herrero, M.; Hormaza, J.I. (December 2015). "Effect of temperature on pollen germination and pollen tube growth in longan ( Dimocarpus longan Lour.)". Scientia Horticulturae. 197: 470–475. Bibcode:2015ScHor.197..470P. doi:10.1016/j.scienta.2015.10.007. hdl:10261/127752. ISSN 0304-4238.
- ^ Teeguarden, Ron. "Tonic Herbs That Every Qigong Practioner [sic] Should Know, Part 2". Qi Journal. Archived from the original on 4 July 2019. Retrieved 4 August 2016.
External links
[edit]- Longan Production in Asia from the Food and Agriculture Organization of the United Nations