Ginkgo biloba
67963
224766038
2008-07-10T09:29:06Z
Casliber
1381068
[[Category:Plants used in bonsai]]
{{otheruses4|the tree|the Goethe poem|Gingo biloba}}
{{expert-verify|date=November 2007}}
{{Taxobox
| name = ''Ginkgo biloba''
| fossil_range = {{fossil range|199.6}}[[Jurassic]] - [[Pliocene]]<ref name=ZhouZheng/>
| status = EN
| status_system = iucn2.3
| status_ref = <ref name="iucn">{{IUCN2006|assessors=Sun|year=1998|id=32353|title=Ginkgo biloba|downloaded=11 May 2006}} Listed as Endangered (EN B1+2c v2.3) </ref>
| image = Ginkgo_Biloba_Leaves_-_Black_Background.jpg
| image_width = 240px
| image_caption = Ginkgo leaves
| regnum = [[Plant]]ae
| divisio = [[Ginkgophyta]]
| classis = [[Ginkgoopsida]]
| ordo = [[Ginkgoales]]
| familia = [[Ginkgoaceae]]
| genus = ''[[Ginkgo]]''
| species = '''''G. biloba'''''
| binomial = ''Ginkgo biloba''
| binomial_authority = [[Carolus Linnaeus|L.]]
}}
The '''Ginkgo''' ('''''Ginkgo biloba'''''; in Chinese 銀杏, [[pinyin]] romanization, '''yín xìng'''), frequently misspelled as "Gingko", and also known as the '''Maidenhair Tree''' after ''[[Adiantum]]'', is a unique [[tree]] with no close living relatives. The ginkgo is classified in its own [[Division (biology)|division]], the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family [[Ginkgoaceae]], genus ''Ginkgo'' and is the only [[Extant_taxon|extant species]] within this group. It is one of the best-known examples of a [[living fossil]], because Ginkgoales are not known from the fossil record after the [[Pliocene]].<ref name=ZhouZheng>{{cite journal
|journal=Nature
|issue=423
|pages=821–822
|date=2003-06-19
| doi=10.1038/423821a
|title=Palaeobiology: The missing link in Ginkgo evolution
|author=Zhiyan Zhou and Shaolin Zheng
| volume = 423
}}</ref>{{Verify source|date=July 2007}}<ref name="ucmp">{{cite web
| url = http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgofr.html
| title = Ginkgoales: Fossil Record
| accessdate = 2008-06-03
| author = Julie Jalalpour, Matt Malkin, Peter Poon, Liz Rehrmann, Jerry Yu
| year = 1997
| format = HTML
| publisher = [[University of California, Berkeley]]
}}</ref>
For centuries it was thought to be extinct in the wild, but is now known to grow in at least two small areas in [[Zhejiang]] province in Eastern [[China]], in the [[Tian Mu Shan Reserve]]. However, recent studies indicate high genetic uniformity among ginkgo trees from these areas, arguing against a natural origin of these populations. Therefore, it has been suggested that the ginkgo trees in these areas appear to have been planted and preserved by Chinese monks over a period of about 1000 years. <ref name="Shen et al">{{cite journal | author= L Shen, X-Y Chen, X Zhang, Y-Y Li, C-X Fu, Y-X Qiu| title= Genetic variation of Ginkgo biloba L. (Ginkgoaceae) based on cpDNA PCR-RFLPs: inference of glacial refugia | journal= Heridity| year= 2005| volume=94|pages=396–401|url=http://www.nature.com/hdy/journal/v94/n4/full/6800616a.html#bib48| doi= 10.1038/sj.hdy.6800616}}</ref> Whether native ginkgo populations still exist has not been demonstrated unequivocally and is therefore uncertain.
The relationship of Ginkgo to other plant groups remains uncertain. It has been placed loosely in the divisions [[Spermatophyta]] and [[Pinophyta]], but no consensus has been reached. Since Ginkgo seeds are not protected by an [[ovary (plants)|ovary]] wall, it can morphologically be considered a [[gymnosperm]]. The apricot-like structures produced by female ginkgo trees are technically not [[fruit]]s, but are the seeds having a shell that consists of a soft and fleshy section (the [[sarcotesta]]), and a hard section (the [[sclerotesta]]).
__TOC__
==Description==
[[Image:Radziejowice ginkgo biloba01.jpg|left|thumb|Ginkgo tree in autumn]]
Ginkgos are very large trees, normally reaching a height of 20–35 m (66-115 feet), with some specimens in China being over 50 m (164 feet). The tree has an angular crown and long, somewhat erratic branches, and is usually deep rooted and resistant to wind and snow damage. Young trees are often tall and slender, and sparsely branched; the crown becomes broader as the tree ages. During autumn, the leaves turn a bright yellow, then fall, sometimes within a short space of time (1–15 days). A combination of resistance to disease, insect-resistant wood and the ability to form aerial roots and sprouts makes ginkgos very long-lived, with some specimens claimed to be more than 2,500 years old: A 3,000 year-old ginkgo has been reported in [[Shandong]] province in China.<ref>A. Lewington & E. Parker (1999). ''Ancient Trees.'' London: Collins & Brown Ltd. ISBN 1-85585-704-9. p. 183.</ref>
Some old Ginkgos produce aerial roots, known as ''chi chi'' (Japanese; "nipples") or ''zhong-ru'' (Mandarin Chinese), which form on the undersides of large branches and grow downwards. Chi chi growth is very slow, and may take hundreds of years to occur. The function, if any, of these thick aerial roots is unknown.
[[Image:Ginkgo Tree Ginkgo biloba Trunk Bark 2000px.jpg|right|thumb|Trunk bark]]
===Stem===
Ginkgo branches grow in length by growth of shoots with regularly spaced leaves, as seen on most trees. From the [[axil]]s of these leaves, "spur shoots" (also known as short shoots) develop on second-year growth. Short shoots have very short internodes (so that several years' growth may only extend them by a centimeter or two) and their leaves are ordinarily unlobed. They are short and knobby, and are arranged regularly on the branches except on first-year growth. Because of the short internodes, leaves appear to be clustered at the tips of short shoots, and reproductive structures are formed only on them (see picture to above left— seeds and leaves are visible on short shoots). In Ginkgos, as in other plants that possess them, short shoots allow the formation of new leaves in the older parts of the crown. After a number of years, a short shoot may change into a long (ordinary) shoot, or vice versa.
===Leaves===
The [[leaf|leaves]] are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting) but never [[anastomosis|anastomosing]] to form a network.<ref name="More on Morphology">[http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgomm.html Ginkgoales: More on Morphology]</ref> Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as dichotomous venation. The leaves are usually 5-10 cm (2-4 inches), but sometimes up to 15 cm (6 inches) long. The old popular name "Maidenhair tree" is because the leaves resemble some of the pinnae of the [[Maidenhair fern]] ''Adiantum capillus-veneris''.
Leaves of long shoots are usually notched or lobed, but only from the outer surface, between the veins. They are borne both on the more rapidly-growing branch tips, where they are alternate and spaced out, and also on the short, stubby spur shoots, where they are clustered at the tips.
===Reproduction===
Ginkgos are [[plant sexuality|dioecious]], with separate sexes, some trees being [[female]] and others being [[male]]. Male plants produce small [[conifer cone|pollen cones]] with [[sporophyll]]s each bearing two [[microsporangium|microsporangia]] spirally arranged around a central axis.
Female plants do not produce cones. Two [[ovule]]s are formed at the end of a stalk, and after [[pollination]], one or both develop into seeds. The seed is 1.5-2 cm long. Its fleshy outer layer (the [[sarcotesta]]) is light yellow-brown, soft, and [[fruit]]-like.
It is attractive in appearance, but contains [[butanoic acid]] and smells like rancid [[butter]] (which contains the same chemical) or feces<ref>Solomon, et al. "Biology" p.523 ISBN 0534492762</ref> when fallen. Beneath the sarcotesta is the hard [[sclerotesta]] (what is normally known as the "shell" of the seed) and a papery [[endotesta]], with the [[nucellus]] surrounding the female [[gametophyte]] at the center.<ref name="Lab IX">[http://www.ucmp.berkeley.edu/IB181/VPL/CorCon/CorCon2.html Laboratory IX -- ''Ginkgo'', ''Cordaites'', and the Conifers]</ref>
The fertilization of ginkgo seeds occurs via motile sperm, as in cycads, ferns, mosses and algae. The sperm are large (about 250-300 micrometres) and are similar to the sperm of cycads, which are slightly larger. Ginkgo sperm were first discovered by the Japanese botanist [[Sakugoro Hirase]] in 1896.<ref>[http://www.biologie.uni-hamburg.de/b-online/fo47/ginkgo/ogura.htm History of Discovery of Spermatozoids In Ginkgo biloba and Cycas revoluta]</ref> The sperm have a complex multi-layered structure, which is a continuous belt of basal bodies that form the base of several thousand flagella which actually have a cilia-like motion. The flagella/cilia apparatus pulls the body of the sperm forwards. The sperm have only a tiny distance to travel to the archegonia, of which there are usually two or three. Two sperm are produced, one of which successfully fertilizes the ovule. Although it is widely held that fertilization of ginkgo seeds occurs just before or after they fall in early autumn,<ref name="More on Morphology"/> <ref name="Lab IX"/> <ref>[http://mac122.icu.ac.jp/ginkgo/icho.html Brief Notes on Ginkgo biloba]</ref> embryos ordinarily occur in seeds just before and after they drop from the tree.<ref>Ben F. Holt, Gar W. Rothwell. Is Ginkgo biloba (Ginkgoaceae) Really an Oviparous Plant? American Journal of Botany, Vol. 84, No. 6 (Jun., 1997) , pp. 870-872</ref>
<gallery heights="140px" widths="180px">
Image:Ginkgo-biloba-male.JPG|Ginkgo pollen cones
Image:Ginkgo embryo and gametophyte.jpg|Female gametophyte, dissected from a seed freshly shed from the tree, containing a well-developed embryo
Image:Ginkgo biloba0.jpg|Ginkgo seeds and leaves
Image:Gingko fg01.jpg|autumn leaves and seeds
</gallery>
==Distribution and habitat==
Although ''Ginkgo biloba'' and other species of the genus were once widespread throughout the world, the tree currently occurs in the wild only in the northwest of [[Zhejiang province]] in the Tianmu Shan mountain reserve in eastern [[China]], but even its status as a naturally occurring species there is questionable. In other areas of China it has been long cultivated and it is common in the southern third of the country.<ref name=florachina>{{Citation| last=Fu| first=Liguo; Li, Nan; Mill, Robert R. | contribution =Ginkgo biloba| year=1999| title=Flora of China| editor-last=Wu| editor-first=Z. Y.; Raven, P.H.; Hong, D.Y.| volume=4| pages=8| place=Beijing| publisher=Science Press; St. Louis: Missouri Botanical Garden Press| contribution-url=http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200005235| accessdate =[[2008-03-31]]}}</ref> It has also been commonly cultivated in North America for over 200 years, but during that time it has never become significantly naturalised.<ref name=USflora>{{Citation| last =Whetstone| first =R. David| contribution =Ginkgo biloba| year =2006| title =Flora of North America| editor-last =Flora of North America Editorial Committee, eds. 1993+| volume =2| contribution-url =http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200005235| place=New York & Oxford| publisher =Oxford University Press}}</ref>
Where it occurs in the wild it is found infrequently in deciduous forests and valleys on acidic [[loess]] (i.e. fine, silty soil) with good drainage. The soil it inhabits is typically in the pH range of 5 to 5.5.<ref name=florachina/>
==Taxonomy and naming==
The species was initially described by the father of taxonomy [[Linnaeus]] in 1771, the specific epithet ''biloba'' derived from the [[Latin]] ''bis'' 'two' and ''loba'' 'lobed', referring to the shape of the leaves.<ref>{{cite book|author = Simpson DP| title = Cassell's Latin Dictionary | publisher = Cassell Ltd.| date = 1979|edition = 5|location = London|pages = 883| isbn=0-304-52257-0}}</ref>
===Etymology===
The older Chinese name for this plant is 銀果 ''yínguǒ'' ('silver fruit').
The most usual names today are 白果 ''bái guǒ'' ('white fruit') and {{lang|zh|銀杏}} ''yínxìng'' ('silver [[apricot]]'). The former name was [[loanword|borrowed]] directly in [[Vietnamese language|Vietnamese]] (as ''bạch quả'').
The latter name was borrowed in [[Japanese language|Japanese]] (as ぎんなん "ginnan") and [[Korean language|Korean]] (as 은행 "eunhaeng"), when the tree itself was introduced from China.
The scientific name ''Ginkgo'' appears to be due to a process akin to [[folk etymology]].
[[Kanji|Chinese characters]] typically have multiple pronunciations in Japanese, and the characters 銀杏 used for ''ginnan'' can also be pronounced ''ginkyō''.
[[Engelbert Kaempfer]], the first [[Westerner]] to see the species in [[1690]], wrote down this pronunciation in his ''Amoenitates Exoticae'' (1712); his ''y'' was misread as a ''g'', and the misspelling stuck.<ref>[http://www.flc.kyushu-u.ac.jp/~michel/serv/ek/amoenitates/ginkgo/ginkgo.html Faculty of languages and cultures, Kyushu University Japan]</ref>
== Prehistory ==
The Ginkgo is a [[living fossil]], with fossils recognisably related to modern Ginkgo from the [[Permian]], dating back 270 million years. They diversified and spread throughout [[Laurasia]] during the middle [[Jurassic]] and [[Cretaceous]], but became much rarer thereafter. By the [[Paleocene]], ''Ginkgo adiantoides'' was the only ''Ginkgo'' species left in the [[Northern Hemisphere]] (but see below) with a markedly different (but not well-documented) form persisting in the [[Southern Hemisphere]], and at the end of the [[Pliocene]] ''Ginkgo'' fossils disappeared from the fossil record everywhere apart from a small area of central China where the modern species survived. It is in fact doubtful whether the Northern Hemisphere fossil species of ''Ginkgo'' can be reliably distinguished; given the slow pace of evolution in the genus, there may have been only 2 in total; what is today called ''G. biloba'' (including ''G. adiantoides''), and ''G. gardneri'' from the [[Paleocene]] of [[Scotland]].
At least morphologically, ''G. gardneri'' and the Southern Hemisphere species are the only known post-Jurassic taxa that can be unequivocally recognised, the remainder may just as well have simply been [[ecotypes]] or [[subspecies]]. The implications would be that ''G. biloba'' had occurred over an extremely wide range, had remarkable genetic flexibility and though [[evolution|evolving]] genetically never showed much [[speciation]]. The occurrence of ''G. gardneri'', it seems a [[Caledonia]]n mountain endemic, and the somewhat greater diversity on the Southern Hemisphere, suggests that old mountain ranges on the Northern Hemisphere could hold other, presently undiscovered, fossil ''Ginkgo'' species. Since the distribution of ''Ginkgo'' was already relictual in late prehistoric times, the chances that ancient [[DNA]] from subfossils can shed any light on this problem seem remote. While it may seem improbable that a species may exist as a contiguous entity for many millions of years, many of the Ginkgo's life-history parameters fit. These are: extreme longevity; slow reproduction rate; (in Cenozoic and later times) a wide, apparently contiguous, but steadily contracting distribution coupled with, as far as can be demonstrated from the fossil record, extreme ecological conservatism (being restricted to light soils around rivers); and a low population density.
<gallery heights="140px" widths="180px">
Image:Ginkgo adiantoides.jpg|''Ginkgo adiantoides'' Eocene fossil leaf from the Tranquille Shale of British Columbia, Canada.
Image:Fossil Plant Ginkgo.jpg|Fossil ''Ginkgo'' leaves from the Jurassic of England
</gallery>
''Ginkgo'' has been used for classifying plants with [[Leaf|leaves]] that have more than four [[Leaf#Veins|veins]] per segment, while ''Baiera'' for those with less than four veins per segment. ''Sphenobaiera'' has been used to classify plants with a broadly wedge-shaped leaf that lacks a distinct leaf stem. ''Trichopitys'' is distinguished by having multiple-forked leaves with cylindrical (not flattened) thread-like ultimate divisions; it is one of the earliest fossils ascribed to the Ginkgophyta.
{{-}}
==Cultivation and uses==
[[Image:Skku logo.png|right|thumb|In [[South Korea]], [[Sungkyunkwan University]]'s logo is a ginkgo leaf. Its main campus features several ginkgo trees that were planted in [[1519]] and still stand today.]]
Ginkgo has long been cultivated in [[China]]; some planted trees at temples are believed to be over 1,500 years old. The first record of Europeans encountering it is in [[1690]] in Japanese temple gardens, where the tree was seen by the German botanist Engelbert Kaempfer. Because of its status in [[Buddhism]] and [[Confucianism]], the Ginkgo is also widely planted in Korea and parts of Japan; in both areas, some naturalization has occurred, with Ginkgos seeding into natural forests.
In some areas, most intentionally planted Ginkgos are male [[cultivar]]s grafted onto plants propagated from seed, because the male trees will not produce the malodorous seeds. The popular cultivar 'Autumn Gold' is a clone of a male plant.
Ginkgos adapt well to the urban environment, tolerating pollution and confined soil spaces.<ref name="Gilman">{{cite web |url=http://hort.ufl.edu/trees/GINBILB.pdf |title=''Ginkgo biloba'' 'Autumn Gold' |author=Gilman, Edward F. and Dennis G. Watson|year=1993|accessdate=2008-03-29 |publisher=US Forest Service}}</ref> They rarely suffer disease problems, even in urban conditions, and are attacked by few insects.<ref name=Boland>{{cite book|author=Boland, Timothy, Laura E. Coit, Marty Hair |url=http://books.google.com.au/books?id=8Ymg47Ccz0kC&pg=PA199&vq=ginkgo&dq=ginkgo+tree+disease&source=gbs_search_r&cad=1_1&sig=usA0cDyB44rlPgbTG3kAwVZtUKI |title= Michigan Gardener's Guide|publisher=Cool Springs Press |year=2002 |id=ISBN 1930604203}}</ref><ref name=SULIS">{{cite web |url=http://www.sustland.umn.edu/design/insect.htm |title=Examples of Plants with Insect and Disease Tolerance|work= SULIS - Sustainable Urban Landscape Information Series|publisher=University of Minnesota |accessdate=2008-03-29 }}</ref> For this reason, and for their general beauty, ginkgos are excellent urban and shade trees, and are widely planted along many streets. The ginkgo is the official tree of the city of [[Kumamoto]], and two leaves form the symbol of the [[University of Tokyo]], the main campus of which is famous for its numerous ginkgos.{{Fact|date=June 2007}}
Ginkgos are also popular subjects for growing as [[penjing]] and [[bonsai]]; they can be kept artificially small and tended over centuries. Furthermore, the trees are easy to propagate from seed.
Extreme examples of the Ginkgo's tenacity may be seen in [[Hiroshima]], [[Japan]], where four trees growing between 1–2 km from the [[1945]] [[atom bomb]] explosion were among the few living things in the area to survive the blast ([http://www.xs4all.nl/~kwanten/hiroshima.htm photos & details]). While almost all other plants (and animals) in the area were destroyed, the ginkgos, though charred, survived and were soon healthy again. The trees are alive to this day.
{{-}}
===Culinary use===
[[Image:Ginkgo-penjing-montreal-botanical-gardens.jpg|thumb|Ginkgo as [[penjing]] in the [[Montreal Botanical Garden]]]]
The nut-like gametophytes inside the seeds are particularly esteemed in Asia, and are a traditional Chinese food. Ginkgo nuts are used in [[congee]], and are often served at special occasions such as weddings and the [[Chinese New Year]] (as part of the vegetarian dish called [[Buddha's delight]]). In Chinese culture, they are believed to have health benefits; some also consider them to have [[aphrodisiac]] qualities. Japanese cooks add Ginkgo seeds (called ''ginnan'') to dishes such as ''[[chawanmushi]]'', and cooked seeds are often eaten along with other dishes. The seeds are available canned, sold as "White Nuts", and can be found in many Asian food stores in the West.
When eaten by children, in large quantities (over 5 seeds a day), or over a long period of time, the raw gametophyte (meat) of the seed can cause poisoning by MPN (4-methoxypyridoxine). MPN is heat-stable. Studies have demonstrated that convulsions caused by MPN can be prevented or terminated with [[pyridoxine]].
Some people are sensitive to the chemicals in the sarcotesta, the outer fleshy coating. These people should handle the seeds with care when preparing the seeds for consumption, wearing disposable gloves. The symptoms are [[dermatitis]] or [[blister]]s similar to that caused by contact with [[Poison-ivy (plant)|poison-ivy]]. However, seeds with the fleshy coating removed are perfectly safe to handle.
{{-}}
[[Image:Ginkgo biloba JPG1a.jpg|thumb|right|Remarkable Ginkgo biloba in [[Tournai]] ([[Belgium]]).|175px]]
===Medicinal uses===
The extract of the Ginkgo leaves contains [[flavonoid]] glycosides and terpenoids ([[ginkgolide]]s, [[bilobalide]]s) and has been used pharmaceutically. It has many alleged [[nootropic]] properties, and is mainly used as [[memory]]<ref name= Mahadevan>{{cite journal
| author= Mahadevan S, Park Y.| title=Multifaceted therapeutic benefits of Ginkgo biloba L.: chemistry, efficacy, safety, and uses. | journal=J Food Sci. | year=2008 | pages=73| volume=1 | issue=14-9 | pmid=18211362| doi=10.1111/j.1750-3841.2007.00597.x| doi_brokendate=2008-06-26}}</ref>
and [[attention|concentration]] enhancer, and anti-[[vertigo (medical)|vertigo]] agent. However, studies differ about its efficacy. [http://www.slate.com/id/2165042/pagenum/all/ Some controversy has arisen] over the conclusions drawn by some studies that were allegedly funded by a firm which marketed Ginkgo. [[Slate (magazine)|''Slate'']], an Internet-based magazine owned by The Washington Post Company, [http://www.slate.com/id/2165042/pagenum/all/ reported in April 2007]:
<blockquote>
In 2002, a long-anticipated paper appeared in ''JAMA'' ([http://jama.ama-assn.org/ ''Journal of the American Medical Association'']) titled "Ginkgo for memory enhancement: a randomized controlled trial." This Williams College study, sponsored by the National Institute on Aging rather than Schwabe, examined the effects of ginkgo consumption on healthy volunteers older than 60. The conclusion, now cited in the National Institutes of Health's [http://nccam.nih.gov/health/ginkgo/ginkgo.pdf ginkgo fact sheet], said: "When taken following the manufacturer's instructions, ginkgo provides no measurable benefit in memory or related cognitive function to adults with healthy cognitive function."
</blockquote>
Out of the many conflicting research results, Ginkgo extract may have three effects on the human body: improvement in blood flow (including microcirculation in small capillaries) to most tissues and organs; protection against oxidative cell damage from free radicals; and blockage of many of the effects of [[Platelet-activating_factor|platelet-activating factor]] (platelet aggregation, blood clotting)<ref>{{cite journal |author=Smith PF, Maclennan K, Darlington CL |title=The neuroprotective properties of the Ginkgo biloba leaf: a review of the possible relationship to platelet-activating factor (PAF) |journal=Journal of ethnopharmacology |volume=50 |issue=3 |pages=131–9 |year=1996 |pmid=8691847| doi = 10.1016/0378-8741(96)01379-7}}</ref> that have been related to the development of a number of cardiovascular, renal, respiratory and CNS (Central Nervous System) disorders. Ginkgo can be used for [[intermittent claudication]].
According to some studies, in a few cases, Ginkgo can significantly improve attention in healthy individuals<ref>{{cite journal |author=Elsabagh S, Hartley DE, Ali O, Williamson EM, File Se |title=Differential cognitive effects of Ginkgo biloba after acute and chronic treatment in healthy young volunteers |journal=Psychopharmacology (Berl) |date=2005 May |volume=179 |issue=2 |pages=437–446 | pmid=15739076 | doi = 10.1007/s00213-005-2206-6}}</ref><ref>BBC News: Herbal remedies "boost brain power".[http://news.bbc.co.uk/2/hi/health/713087.stm]</ref>. The effect is almost immediate and reaches its peak in 2.5 hours after the intake<ref>[http://www.springerlink.com/content/ggk68t2cau2dpmrd/ Dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers.]</ref>.
A [[2004]] conference paper<ref name="alzheim">{{cite conference| author=L. Witkam and I. Ramzan| title=Ginkgo biloba in the treatment of Alzheimer’s disease: A miracle cure?| booktitle=From Cell to Society| year=2004}} [http://www.chs.usyd.edu.au/conf04/submit/minipost/bv-witka.pdf full text pdf] [http://www.chs.usyd.edu.au/conf04/ Conference page].</ref> summarizes how various trials indicate that Ginkgo shows promise in the treatment of [[Alzheimer's disease]], though a 2008 study found it ineffective at treating [[dementia]].<ref>{{cite news | url = http://news.bbc.co.uk/2/hi/health/7453167.stm | title = Ginkgo 'does not treat dementia' | work = BBC News | date = [[June 16]], [[2008]]}}</ref>
There have been studies [http://www.bixby.org/faq/tinnitus/treatmnt.html#gingko] which suggest there may be a link between ginkgo and the easing of the symptoms of [[tinnitus]].
Ginkgo is commonly added to [[energy drink]]s, but the amount is typically [[angel dusting|so low]] it does not produce a noticeable effect, except perhaps via a [[placebo effect]] from Ginkgo being listed on the label.{{Verify source|date=May 2008}}
Ginkgo supplements are usually taken in the range of 40–200 mg per day.
A 2003 study conducted by the Department of Dermatology, Postgraduate Institute of Medical Education and Research in Chandigarh, India concluded that Ginkgo is an effective treatment for arresting the development of vitiligo[http://www.ncbi.nlm.nih.gov/pubmed/12780716].
====Side effects====
Ginkgo may have some undesirable effects, especially for individuals with blood circulation disorders and those taking [[anticoagulant]]s such as [[ibuprofen]], [[aspirin]], or [[warfarin]], although recent studies have found that ginkgo has little or no effect on the anticoagulant properties or pharmacodynamics of [[warfarin]]<ref name="warfarin">{{cite journal | quotes=no | author= Xuemin Jiang ''et al''| title= Effect of ginkgo and ginger on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects | journal= British Journal of Clinical Pharmacology| year= 2005| volume= 59| issue= 4| pages= 425–432| doi= 10.1111/j.1365-2125.2005.02322.x }}</ref><ref name="review">{{cite journal | quotes=no | author= Ernst E, Canter PH, Coon JT| title= Does ginkgo biloba increase the risk of bleeding? A systematic review of case reports | journal= Perfusion| year= 2005| volume= 18| pages= 52–56 }}</ref>. Ginkgo should also not be used by people who are taking certain types of antidepressants ([[monoamine oxidase inhibitor|MAOIs]] and [[selective serotonin reuptake inhibitor|SSRIs]]<ref>{{cite web| title=MedlinePlus Herbs and Supplements: Ginkgo (Ginkgo biloba L.)| accessdate=2008-04-10| publisher=National Institutes of Health| url=http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-ginkgo.html#Interactions}}</ref><ref name="UofMarylandMC">{{cite web| title=Ginkgo biloba| accessdate=2008-04-10| publisher=University of Maryland Medical Center| url=http://www.umm.edu/altmed/articles/ginkgo-biloba-000247.htm}}</ref>) or by [[pregnancy|pregnant]] women without first consulting a doctor.
Ginkgo side effects and cautions include: possible increased risk of bleeding, gastrointestinal discomfort, nausea, vomiting, diarrhea, headaches, dizziness, heart palpitations, and restlessness. <ref>[http://www.drugs.com/npp/ginkgo.html Complete Ginkgo information from Drugs.com<!-- Bot generated title -->]</ref><ref name="UofMarylandMC" /> If any side effects are experienced, consumption should be stopped immediately.
[[Image:Gingko biloba JPG2b.jpg|thumb|right|''Ginkgo biloba'' in [[Morlanwelz-Mariemont]] Park, [[Belgium]]]]
==See also==
*[[André Michaux]], ''introduced the ginkgo to North America''
*[[Antioxidant]]
*[[Ginkgo/Wanapum State Park]] in central [[Washington]], USA
*[[Herbalism]]
* [[List of edible seeds]]
*[[Naturopathic medicine]]
==References==
{{reflist}}
==External links==
{{wikispecies|Ginkgo biloba}}
{{commons|Ginkgo biloba}}
*[http://www.xs4all.nl/~kwanten The Ginkgo Pages]: all aspects, in English, German, French, Spanish and Dutch. This non-commercial homepage also provides a literature/reference page.
*[http://www.conifers.org/gi/gi/index.htm Gymnosperm Database]
*[http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgo.html Info] by the [[University of California Museum of Paleontology]]
*[http://www.phytochemicals.info/ginkgo.php Phytochemicals in ginkgo]
*[http://www.planet-weimar.de/english/index.html The Ginkgo Museum], [[Weimar, Germany]]
*[http://www.ottawahort.org/ginkgo.htm Growing Ginkgoes from seed]: by the Ottawa Horticultural Society
*[http://faculty.washington.edu/chudler/ginkgo.html Neuroscience for kids]: Refers to JAMA studies on efficacy
*[http://www.cas.vanderbilt.edu/bioimages/species/frame/gibi2.htm ''Ginkgo biloba'' images at bioimages.vanderbilt.edu]
*[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9611693 Ginkgo biloba for antidepressant-induced sexual dysfunction]
*[http://www.cirrusimage.com/tree_Ginkgo.htm Ginkgo biloba] Large format diagnostic photos, information.
*[http://www.naturaldatabase.com/nd/Search.aspx?sample=1&rh=1 Ginkgo Evidence-based Monograph] from ''Natural Medicines Comprehensive Database''
__notoc__
[[Category:Plants used in bonsai]]
[[Category:Gymnosperms]]
[[Category:Living fossils]]
[[Category:Medicinal plants]]
[[Category:Horticulture]]
[[Category:Ornamental trees]]
[[ar:جنكو]]
[[roa-rup:Ginkgo biloba]]
[[bg:Гинко]]
[[ca:Ginkgo]]
[[cs:Jinan dvoulaločný]]
[[cy:Coeden ginco]]
[[da:Tempeltræ]]
[[de:Ginkgo]]
[[et:Hõlmikpuu]]
[[el:Γκίγκο]]
[[es:Ginkgo biloba]]
[[eo:Ginko]]
[[fa:ژینکو]]
[[fr:Ginkgo biloba]]
[[gl:Xinkgo]]
[[ko:은행나무]]
[[id:Ginkgo]]
[[it:Ginkgo biloba]]
[[he:גינקגו דו-אונתי]]
[[ka:გინკგო]]
[[la:Ginkgo]]
[[lv:Ginki]]
[[lb:Ginkgo]]
[[lt:Dviskiautis ginkmedis]]
[[hu:Ginkgo biloba]]
[[nl:Ginkgo biloba]]
[[ja:イチョウ]]
[[no:Tempeltre]]
[[pl:Miłorząb dwuklapowy]]
[[pt:Ginkgo]]
[[ro:Ginkgo]]
[[ru:Гинкго]]
[[simple:Ginkgo]]
[[sk:Ginko dvojlaločné]]
[[sl:Dvokrpi ginko]]
[[sr:Гинко]]
[[fi:Neidonhiuspuut]]
[[sv:Ginkgo]]
[[th:แปะก๊วย]]
[[vi:Bạch quả]]
[[tr:Mabet ağacı]]
[[uk:Гінкго дволопатеве]]
[[zh:银杏]]