Ginkgo Biloba
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''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of tree native to
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. It is the last living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossils very similar to the living species, belonging to the genus ''
Ginkgo ''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus with ...
'', extend back to the
Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...
approximately 170 million years ago. The tree was cultivated early in
human history Human history, also called world history, is the narrative of humanity's past. It is understood and studied through anthropology, archaeology, genetics, and linguistics. Since the invention of writing, human history has been studied throug ...
and remains commonly planted. Ginkgo leaf
extract An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts, h ...
is commonly used as a dietary supplement, but there is no
scientific evidence Scientific evidence is evidence that serves to either support or counter a scientific theory or hypothesis, although scientists also use evidence in other ways, such as when applying theories to practical problems. "Discussions about empirical ev ...
that it supports human health or is effective against any disease.


Etymology

The genus name is regarded as a misspelling of the Japanese pronunciation ''gin kyo'' for the
kanji are the logographic Chinese characters taken from the Chinese family of scripts, Chinese script and used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese ...
銀杏 meaning "silver apricot", which is found in
Chinese herbology Chinese herbology () is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). A ''Nature'' editorial described TCM as "fraught with pseudoscience", and said that t ...
literature such as (Daily Use Materia Medica) (1329) and ''
Compendium of Materia Medica The ''Bencao gangmu'', known in English as the ''Compendium of Materia Medica'' or ''Great Pharmacopoeia'', is an encyclopedic gathering of medicine, natural history, and Chinese herbology compiled and edited by Li Shizhen and published in the ...
'' published in 1578.T. Hori, A historical survey of Ginkgo biloba based on Japanese and Chinese classical literatures, Plant Morphology, 2001, 31, 31-40 Despite its spelling, which is due to a complicated etymology including a transcription error, "ginkgo" is usually pronounced , which has given rise to the common alternative spelling "gingko". The
spelling pronunciation A spelling pronunciation is the pronunciation of a word according to its spelling when this differs from a longstanding standard or traditional pronunciation. Words that are spelled with letters that were never pronounced or that were not pronounc ...
is also documented in some dictionaries.
Engelbert Kaempfer Engelbert Kaempfer (16 September 16512 November 1716) was a German naturalist, physician, explorer and writer known for his tour of Russia, Persia, India, Southeast Asia, and Japan between 1683 and 1693. He wrote two books about his travels. ''A ...
first introduced the spelling ''ginkgo'' in his book ''Amoenitatum Exoticarum''. It is considered that he may have misspelled "Ginkyo" as "Ginkgo". This misspelling was included by
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in his book ''Mantissa plantarum II'' and has become the name of the tree's genus.


Description

Ginkgos are large trees, normally reaching a height of , with some specimens in China being over . The tree has an angular
crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...
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. A combination of resistance to disease, insect-resistant wood, and the ability to form
aerial root Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such as mangroves, banyan figs (''Fic ...
s and sprouts makes ginkgos durable, with some specimens claimed to be more than 2,500 years old.


Leaves

The
leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never
anastomosing An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...
to form a network. Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as
dichotomous venation A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
. The leaves are usually , but sometimes up to long. The old common name, ''maidenhair tree'', derives from the leaves resembling
pinnae The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna (Latin for "wing" or " fin", plural pinnae), a term that is used more in zoology. Structure The diagram shows the shape and location ...
of the maidenhair fern, ''
Adiantum capillus-veneris ''Adiantum capillus-veneris'', the Southern maidenhair fern, black maidenhair fern, maidenhair fern, and venus hair fern, is a species of ferns in the genus ''Adiantum'' and the family Pteridaceae with a subcosmopolitan worldwide distribution. I ...
''. Ginkgos are prized for their autumn foliage, which is a deep saffron yellow. 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. Leaves are green both on the top and bottom and have stomata on both sides. During autumn, the leaves turn a bright yellow and then fall, sometimes within a short space of time (one to 15 days).


Branches

Ginkgo branches grow in length by growth of shoots with regularly spaced leaves, as seen on most trees. From the
axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
s of these leaves, "spur shoots" (also known as short shoots) develop on second-year growth. Short shoots have very short internodes (so they may grow only one or two centimeters in several years) and their leaves are usually 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 pictures below – 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. Ginkgo prefers full sun and grows best in environments that are well-watered and well-drained. The species shows a preference for disturbed sites; in the "semiwild" stands at
Tianmu Mountain Tianmu Mountain, Mount Tianmu, or Tianmushan () is a mountain in Lin'an County west of Hangzhou, Zhejiang, in eastern China. It is made up of two peaks: West Tianmu () and East Tianmu (). Twin ponds near the top of the peaks led to the name of ...
s, many specimens are found along stream banks, rocky slopes, and cliff edges. Accordingly, ginkgo retains a prodigious capacity for vegetative growth. It is capable of sprouting from embedded buds near the base of the trunk (
lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a response t ...
s, or basal chichi) in response to disturbances, such as soil erosion. Old individuals are also capable of producing aerial roots on the undersides of large branches in response to disturbances such as crown damage; these roots can lead to successful clonal reproduction upon contacting the soil. These strategies are evidently important in the persistence of ginkgo; in a survey of the "semiwild" stands remaining in
Tianmushan Tianmu Mountain, Mount Tianmu, or Tianmushan () is a mountain in Lin'an County west of Hangzhou, Zhejiang, in eastern China. It is made up of two peaks: West Tianmu () and East Tianmu (). Twin ponds near the top of the peaks led to the name o ...
, 40% of the specimens surveyed were multi-stemmed, and few saplings were present.


Reproduction

''Ginkgo biloba'' is
dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...
, with separate
sexes Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones ( ova, of ...
, some trees being
female Female (Venus symbol, symbol: ♀) is the sex of an organism that produces the large non-motile ovum, ova (egg cells), the type of gamete (sex cell) that fuses with the Sperm, male gamete during sexual reproduction. A female has larger gamet ...
and others being
male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot reproduce sexually without access to ...
. Male plants produce small pollen cones with
sporophyll A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or ...
s, each bearing two
microsporangia Microsporangia are sporangia that produce microspores that give rise to male gametophytes when they germinate. Microsporangia occur in all vascular plants that have heterosporic life cycles, such as seed plants, spike mosses and the aquatic fer ...
spirally arranged around a central axis. Female plants do not produce cones. Two
ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fe ...
s are formed at the end of a stalk, and after
wind pollination Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous plan ...
, one or both develop into seeds. The seed is 1.5–2 cm long. Its fleshy outer layer (the
sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument In biology, an integu ...
) is light yellow-brown, soft, and
fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
-like. It is attractive in appearance, but contains butyric acid (also known as butanoic acid) and smells like rancid
butter Butter is a dairy product made from the fat and protein components of churned cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condiment ...
or vomit when fallen. Beneath the sarcotesta is the hard sclerotesta (the "shell" of the seed) and a papery endotesta, with the
nucellus In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the '' nucellus'' (or remnant of the megasporangium), and the f ...
surrounding the female
gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...
at the center. The fertilization of ginkgo seeds occurs via
motile Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
sperm, as in cycads, ferns, mosses, and algae. The sperm are large (about 70–90 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. 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. Fertilization of ginkgo seeds occurs just before or after they fall in early autumn. Embryos may develop in the seeds before or after they drop from the tree.


Genome

Chinese scientists published a draft
genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
of ''Ginkgo biloba'' in 2016. The tree has a large genome of 10.6 billion DNA
nucleobase Nucleobases, also known as ''nitrogenous bases'' or often simply ''bases'', are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic b ...
"letters" (the human genome has three billion) and about 41,840 predicted
gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
s which enable a considerable number of antibacterial and chemical defense mechanisms. 76.58% of the assembled sequence turned out to be repetitive sequences. In 2020, a study in China of
ginkgo ''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus with ...
trees up to 667 years old showed little effects of aging, finding that the trees continued to grow with age and displayed no genetic evidence of
senescence Senescence () or biological aging is the gradual deterioration of functional characteristics in living organisms. The word ''senescence'' can refer to either cellular senescence or to senescence of the whole organism. Organismal senescence inv ...
, and continued to make phytochemicals indefinitely.


Phytochemicals

Extracts of ginkgo leaves contain
phenolic acid Phenolic acids or phenolcarboxylic acids are types of aromatic acid compounds. Included in that class are substances containing a phenolic ring and an organic carboxylic acid function (C6-C1 skeleton). Two important naturally occurring types of ...
s,
proanthocyanidin Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More compl ...
s, flavonoid glycosides, such as
myricetin Myricetin is a member of the flavonoid class of polyphenolic compounds, with antioxidant properties. Common dietary sources include vegetables (including tomatoes), fruits (including oranges), nuts, berries, tea, and red wine. Myricetin is struc ...
,
kaempferol Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol, a type of flavonoid, found in a variety of plants and plant-derived foods including kale, beans, tea, spinach, and broccoli. Kaempferol is a yellow crystalline solid with a meltin ...
,
isorhamnetin Isorhamnetin is an O-methylated flavon-ol from the class of flavonoids. A common food source of this 3'-methoxylated derivative of quercetin and its glucoside conjugates are pungent yellow or red onions, in which it is a minor pigment, quercetin ...
, and
quercetin Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor ...
, and the
terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes ...
trilactones
ginkgolide Ginkgolides are biologically active terpenic lactones present in ''Ginkgo biloba''. They are diterpenoids with 20-carbon skeletons, which are biosynthesized from geranylgeranyl pyrophosphate. Examples Ginkgolide B Ginkgolide B, specificall ...
s and bilobalides. The leaves also contain unique ginkgo biflavones,
alkylphenol Alkylphenols are a family of organic compounds obtained by the alkylation of phenols. The term is usually reserved for commercially important propylphenol, butylphenol, amylphenol, heptylphenol, octylphenol, nonylphenol, dodecylphenol and related ...
s, and
polyprenol Polyprenols are natural long-chain isoprenoid alcohols of the general formula H-(C5H8)n-OH where n is the number of isoprene units. Any prenol with more than 4 isoprene units is a polyprenol. Polyprenols play an important function acting as natura ...
s.


Taxonomy

The older Chinese name for this plant is 銀果, meaning "silver fruit", pronounced ''yínguǒ'' in Mandarin or ''Ngan-gwo'' in Cantonese. The current commonly used names are 白果 (), meaning "white fruit", and (), meaning "silver apricot". The name 銀杏 was borrowed in
Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...
イチョウ () or ぎんなん () and
Korean Korean may refer to: People and culture * Koreans, ethnic group originating in the Korean Peninsula * Korean cuisine * Korean culture * Korean language **Korean alphabet, known as Hangul or Chosŏn'gŭl **Korean dialects and the Jeju language ** ...
은행 (), when the tree was introduced from China.
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
described the species in 1771, the
specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
''biloba'' derived from the
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''bis'', "twice" and ''loba'', "lobed", referring to the shape of the leaves. Two names for the species recognise the botanist Richard Salisbury, a placement by Nelson as ''Pterophyllus salisburiensis'' and the earlier ''Salisburia adiantifolia'' proposed by
James Edward Smith James Edward Smith may refer to: * James Edward Smith (botanist), English botanist and founder of the Linnean Society * James Edward Smith (murderer), American murderer * James Edward Smith (politician), Canadian businessman and mayor of Toronto * ...
. The epithet of the latter may have been intended to denote a characteristic resembling ''
Adiantum ''Adiantum'' (), the maidenhair fern, is a genus of about 250 species of ferns in the subfamily Vittarioideae of the family Pteridaceae, though some researchers place it in its own family, Adiantaceae. The genus name comes from Greek, meaning "un ...
'', the genus of maidenhair ferns. The scientific name ''Ginkgo'' is the result of a spelling error that occurred three centuries ago. ''
Kanji are the logographic Chinese characters taken from the Chinese family of scripts, Chinese script and used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese ...
'' typically have multiple pronunciations in Japanese, and the characters 銀杏 used for ''ginnan'' can also be pronounced ''ginkyō''.
Engelbert Kaempfer Engelbert Kaempfer (16 September 16512 November 1716) was a German naturalist, physician, explorer and writer known for his tour of Russia, Persia, India, Southeast Asia, and Japan between 1683 and 1693. He wrote two books about his travels. ''A ...
, the first Westerner to investigate the species in 1690, wrote down this pronunciation in the notes that he later used for the ''Amoenitates Exoticae'' (1712) with the "awkward" spelling "ginkgo". This appears to be a simple error of Kaempfer; taking his spelling of other Japanese words containing the syllable "kyō" into account, a more precise
romanization Romanization or romanisation, in linguistics, is the conversion of text from a different writing system to the Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and ...
following his writing habits would have been "ginkio" or "ginkjo". Linnaeus, who relied on Kaempfer when dealing with Japanese plants, adopted the spelling given in Kaempfer's "Flora Japonica" (''Amoenitates Exoticae'', p. 811). Kaempfer's drawing can be found in Hori's article.


Classification

The relationship of ginkgo to other plant groups remains uncertain. It has been placed loosely in the divisions
Spermatophyta A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...
and
Pinophyta Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extan ...
, but no consensus has been reached. Since its seeds are not protected by an
ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...
wall, it can morphologically be considered a
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, ''Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνό ...
. The apricot-like structures produced by female ginkgo trees are technically not
fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
s, but are seeds that have a shell consisting of a soft and fleshy section (the
sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument In biology, an integu ...
), and a hard section (the sclerotesta). The sarcotesta has a strong smell that most people find unpleasant. The ginkgo is classified in its own
division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting ...
, the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family
Ginkgoaceae The Ginkgoaceae is a family of gymnosperms which appeared during the Mesozoic Era, of which the only extant representative is ''Ginkgo biloba'', which is for this reason sometimes regarded as a living fossil A living fossil is an extant tax ...
, genus ''
Ginkgo ''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus with ...
'' and is the only
extant species Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, ''recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members st ...
within this group. It is one of the best-known examples of a
living fossil A living fossil is an extant taxon that cosmetically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossi ...
, because Ginkgoales other than ''G. biloba'' are not known from the fossil record after the
Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 File:Ginkgo yimaensis.jpg, Extinct ''
Ginkgo yimaensis ''Ginkgo yimaensis'' is an extinct ginkgo species in the family Ginkgoaceae. It is a gymnosperm, first described by Zhou and Zhang. Description ''Ginkgo yimaensis'' differs from the extant '' G. biloba'' only slightly. The leaves were deeply di ...
''Approximate reconstructions by B. M. Begović Bego and Z. Zhou, 2010/2011. Source: B.M. Begović Bego, (2011). Nature's Miracle ''Ginkgo biloba'', Book 1, Vols. 1–2, pp. 60–61. File:Ginkgo apodes.jpg, Extinct '' Ginkgo apodes'' File:Ginkgo adiantoides - G. cranii.jpg, Extinct ''
Ginkgo adiantoides ''Ginkgo adiantoides'' is an extinct ginkgo species in the family Ginkgoaceae from the Late Cretaceous to the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by ...
'', or possibly a new taxon from the US, '' G. cranei'' File:Ginkgo biloba (new form).jpg, Extant ''Ginkgo biloba''


Evolution

''Ginkgo biloba'' is a
living fossil A living fossil is an extant taxon that cosmetically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossi ...
, with fossils recognisably related to modern ginkgo from the early
Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...
(
Cisuralian The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the w ...
), with likely oldest record being that of '' Trichopitys'' from the earliest Permian (
Asselian In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between and million years ago (Ma) ...
) of France, over 290 million years old. The closest living relatives of the
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
are the
cycads Cycads are seed plants that typically have a stout and woody ( ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male o ...
, which share with the extant ''G. biloba'' the characteristic of
motile Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
sperm. Such plants with
leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
that have more than four
veins Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
per segment have customarily been assigned to the taxon ''Ginkgo'', while the taxon ''
Baiera ''Baiera'' is a genus of prehistoric gymnosperms in the order Ginkgoales. It is one of the oldest fossil foliage types of Ginkgoales, and is related to the genera ''Ginkgo'' and '' Ginkgoites''. Fossils of ''Baiera'' are found worldwide, and ha ...
'' is used to classify those with fewer than four veins per segment. ''
Sphenobaiera ''Sphenobaiera'' is a form genus for plant leaves found in rocks from Triassic to Cretaceous periods. The genus ''Sphenobaiera'' is used for plants with wedge-shaped leaves that can be distinguished from ''Ginkgo'', ''Ginkgoites'' and ''Baiera'' ...
'' has been used for plants with a broadly wedge-shaped leaf that lacks a distinct leaf stem.


Rise and decline

Fossils attributable to the genus ''Ginkgo'' first appeared in the
Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...
. The genus ''Ginkgo'' diversified and spread throughout
Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...
during the
Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
and
Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145  Ma to 100.5 Ma. Geology Pro ...
. The Ginkgophyta declined in diversity as the Cretaceous progressed, and by the
Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...
, ''
Ginkgo adiantoides ''Ginkgo adiantoides'' is an extinct ginkgo species in the family Ginkgoaceae from the Late Cretaceous to the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by ...
'' was the only ''Ginkgo'' species left in the
Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
, while a markedly different (and poorly documented) form persisted in the Southern Hemisphere. Along with that of ferns, cycads, and cycadeoids, the species diversity in the genus ''Ginkgo'' drops through the Cretaceous, at the same time the flowering plants were on the rise; this supports the hypothesis that, over time, flowering plants with better adaptations to disturbance displaced ''Ginkgo'' and its associates. At the end of the
Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58central China Central China () is a geographical and a loosely defined cultural region that includes the provinces of Henan, Hubei and Hunan. Jiangxi is sometimes also regarded to be part of this region. Central China is now officially part of South Central ...
, where the modern species survived.


Limited number of species

It is doubtful whether the Northern Hemisphere fossil species of ''Ginkgo'' can be reliably distinguished. Given the slow pace of evolution and morphological similarity between members of the genus, there may have been only one or two species existing in the Northern Hemisphere through the entirety of the
Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...
: present-day ''G. biloba'' (including ''G. adiantoides'') and '' G. gardneri'' from the
Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...
of
Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
. 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 have been
ecotype In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a specie ...
s or
subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
. The implications would be that ''G. biloba'' had occurred over an extremely wide range, had remarkable genetic flexibility and, though
evolving Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
genetically, never showed much
speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...
. While it may seem improbable that a single species may exist as a contiguous entity for many millions of years, many of the ginkgo's life-history parameters fit: Extreme longevity; slow reproduction rate; (in Cenozoic and later times) a wide, apparently contiguous, but steadily contracting distribution; and (as far as can be demonstrated from the fossil record) extreme ecological conservatism (restriction to disturbed streamside environments).


Adaptation to a single environment

Given the slow rate of evolution of the genus, ''Ginkgo'' possibly represents a pre-
angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
strategy for survival in disturbed streamside environments. ''Ginkgo'' evolved in an era before flowering plants, when
fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...
s,
cycad Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...
s, and cycadeoids dominated disturbed streamside environments, forming low, open, shrubby canopies. ''Ginkgo'' large seeds and habit of "bolting" – growing to a height of 10 meters before elongating its side branches – may be adaptations to such an environment. Modern-day ''G. biloba'' grows best in environments that are well-watered and drained, and the extremely similar fossil ''Ginkgo'' favored similar environments: The sediment record at the majority of fossil ''Ginkgo'' localities indicates it grew primarily in disturbed environments, such as along streams. ''Ginkgo'', therefore, presents an "ecological paradox" because while it possesses some favorable traits for living in disturbed environments (clonal reproduction) many of its other life-history traits are the opposite of those exhibited by modern plants that thrive in disturbed settings (slow growth, large seed size, late reproductive maturity).


Distribution and habitat

Although ''Ginkgo biloba'' and other species of the genus were once widespread throughout the world, its range shrank and by two million years ago, it was restricted to a small area of
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. 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 Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Jiang ...
province in eastern China, in the
Tianmushan Tianmu Mountain, Mount Tianmu, or Tianmushan () is a mountain in Lin'an County west of Hangzhou, Zhejiang, in eastern China. It is made up of two peaks: West Tianmu () and East Tianmu (). Twin ponds near the top of the peaks led to the name o ...
Reserve. However, high genetic uniformity exists among ginkgo trees from these areas, arguing against a natural origin of these populations and suggesting the ginkgo trees in these areas may have been planted and preserved by Chinese monks over a period of about 1,000 years. This study demonstrates a greater genetic diversity in
Southwestern China Southwest China () is a region in the south of the People's Republic of China. Geography Southwest China is a rugged and mountainous region, transitioning between the Tibetan Plateau to the west and the Chinese coastal hills (东南丘陵) and ...
populations, supporting glacial refugia in mountains surrounding eastern
Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the Ti ...
, where several old-growth candidates for wild populations have been reported. Whether native ginkgo populations still exist has not been demonstrated unequivocally, but there is genetic evidence that these Southwestern populations may be wild, as well as evidence that the largest and oldest ''Ginkgo biloba'' trees may be older than surrounding human settlements. Where it occurs in the wild, it is found infrequently in deciduous forests and valleys on acidic
loess Loess (, ; from german: Löss ) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loess or similar deposits. Loess is a periglacial or aeolian ...
(i.e. fine, silty soil) with good drainage. The soil it inhabits is typically in the pH range of 5.0 to 5.5.


Cultivation

Ginkgo has long been cultivated in China. It is common in the southern third of the country. 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 Engelbert Kaempfer (16 September 16512 November 1716) was a German naturalist, physician, explorer and writer known for his tour of Russia, Persia, India, Southeast Asia, and Japan between 1683 and 1693. He wrote two books about his travels. ''A ...
. Because of its status in
Buddhism Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religion or philosophical tradition based on teachings attributed to the Buddha. It originated in northern India as a -movement in the 5th century BCE, and gra ...
and
Confucianism Confucianism, also known as Ruism or Ru classicism, is a system of thought and behavior originating in ancient China. Variously described as tradition, a philosophy, a religion, a humanistic or rationalistic religion, a way of governing, or ...
, the ginkgo is also widely planted in Korea and in Japan since the 14th century; in both areas, some naturalization has occurred, with ginkgos seeding into natural forests. Ginkgo has been commonly cultivated in North America for over 200 years and in Europe for close to 300, but during that time, it has never become significantly naturalized. Many intentionally planted ginkgos are male
cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...
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. The disadvantage of male ''Ginkgo biloba'' trees is that they are highly allergenic. They have an OPALS (
Ogren Plant Allergy Scale The Ogren Plant Allergy Scale (OPALS) is an allergy rating system for plants that measures the potential of a plant to cause allergic reactions in humans. Scale system The OPALS allergy scale was first published in ''Allergy-Free Gardening'', b ...
) rating of 7 (out of 10), whereas female trees, which can produce no
pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
, have an OPALS allergy scale rating of 2. Female cultivars include 'Liberty Splendor', 'Santa Cruz', and 'Golden Girl', the latter so named because of the striking yellow color of its leaves in the fall; all female cultivars release zero pollen. Many cultivars are listed in the literature in the UK, of which the compact 'Troll' has gained the
Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...
's
Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...
. Ginkgos adapt well to the urban environment, tolerating pollution and confined soil spaces. They rarely have disease problems, even in urban conditions, and are attacked by few insects. Ginkgos are popular subjects for growing as miniature landscapes known as ''
penjing ''Penjing'', also known as ''penzai'', is the ancient Chinese art of depicting artistically formed trees, other plants, and landscapes in miniature. Penjing generally fall into one of three categories: * Shumu penjing (樹木盆景): Tree penjin ...
'' and ''
bonsai Bonsai ( ja, 盆栽, , tray planting, ) is the Japanese art of growing and training miniature trees in pots, developed from the traditional Chinese art form of ''penjing''. Unlike ''penjing'', which utilizes traditional techniques to produce ...
''; they can be kept artificially small and tended over centuries. The trees are easy to propagate from seed.


Hiroshima

Extreme examples of the ginkgo's tenacity may be seen in
Hiroshima is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui h ...
, Japan, where six trees growing between from the 1945 atom bomb explosion were among the few living
organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
s in the area to survive the blast. Although almost all other plants (and animals) in the area were killed, the ginkgos, though charred, survived and were soon healthy again, among other ''
hibakujumoku ''Hibakujumoku'' ( ja, 被爆樹木; also called survivor tree or A-bombed tree in English) is a Japanese term for a tree that survived the atomic bombings of Hiroshima and Nagasaki in 1945. The term is from ja, 被爆, hibaku, bombed, A-bomb ...
'' (trees that survived the blast). The six trees are still alive: They are marked with signs at temple (planted in 1850),
Shukkei-en is a historic Japanese garden in the city of Hiroshima, Japan. The Hiroshima Prefectural Art Museum is located adjacent to the garden. History Construction began in 1620 during the Edo period at the order of Asano Nagaakira, ''daimyō'' of the ...
(planted about 1740), Jōsei-ji (planted 1900), at the former site of Senda Elementary School near Miyukibashi, at the Myōjōin temple, and an
Edo period The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was characteriz ...
-cutting at Anraku-ji temple.


1000-year-old ginkgo at Tsurugaoka Hachimangū

The ginkgo tree that stood next to Tsurugaoka Hachiman-gū's stone stairway approximately from the Shinto shrine's foundation in 1063, and which appears in almost every old depiction of the shrine, was blown down on 10 March 2010. The remaining roots of the tree later sprouted vigorously. The shrine is in the city of Kamakura,
Kanagawa Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-densest at . Its geographic area of makes it fifth-smallest. Kana ...
,
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. The tree was nicknamed ''kakure-ichō'' (hiding ginkgo), derived from an
Edo period The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was characteriz ...
legend A legend is a Folklore genre, genre of folklore that consists of a narrative featuring human actions, believed or perceived, both by teller and listeners, to have taken place in human history. Narratives in this genre may demonstrate human valu ...
in which
Minamoto no Sanetomo was the third ''shōgun'' of the Kamakura shogunate. He was the second son of the Kamakura shogunate founder, Minamoto no Yoritomo. His mother was Hōjō Masako and his older brother was second Kamakura shogun Minamoto no Yoriie. His childhood ...
is assassinated on 13 February 1219 by his nephew, Kugyō, who had been hiding behind the tree. In fact ginkgos arrived from China in the 14th century, and a 1990 tree-ring measurement indicated the tree's age to be about 500 years.


Uses

The wood of ''Ginkgo biloba'' is used to make
furniture Furniture refers to movable objects intended to support various human activities such as seating (e.g., stools, chairs, and sofas), eating (tables), storing items, eating and/or working with an item, and sleeping (e.g., beds and hammocks). Fu ...
,
chessboard A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the bo ...
s, carving, and casks for making
saké Sake, also spelled saké ( ; also referred to as Japanese rice wine), is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indee ...
; the wood is fire-resistant and slow to decay.


Culinary

The nut-like
gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...
s inside the seeds are particularly esteemed in Asia, and are a traditional
Chinese food Chinese cuisine encompasses the numerous cuisines originating from China, as well as overseas cuisines created by the Overseas Chinese, Chinese diaspora. Because of the Chinese diaspora and historical power of the country, Chinese cuisine ha ...
. 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 Buddha's delight, often transliterated as ''Luóhàn zhāi'', ''lo han jai'', or ''lo hon jai'', is a vegetarian dish well known in Chinese and Buddhist cuisine. It is sometimes also called ''Luóhàn cài'' (). The dish is traditionally enjo ...
). Japanese cooks add ginkgo seeds (called ''ginnan'') to dishes such as ''
chawanmushi is an egg custard dish in Japanese cuisine. Unlike many other custards, it is usually eaten as a dish in a meal, as chawanmushi contains savory rather than sweet ingredients. The custard consists of an egg mixture flavored with soy sauce, dashi, ...
'', and cooked seeds are often eaten along with other dishes. When eaten in large quantities or over a long period, the gametophyte (meat) of the seed may cause poisoning by ginkgotoxin (4'-O-methylpyridoxine, MPN), as found in a few
case report In medicine, a case report is a detailed report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient. Case reports may contain a demographic profile of the patient, but usually describe an unusual or novel occurrence ...
s. A heat-stable compound not destroyed by cooking, MPN may cause convulsions, which were alleviated by treatment with pyridoxine
phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...
(vitamin B6), according to limited studies. Some people are sensitive to the chemicals in the
sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument In biology, an integu ...
, the outer fleshy coating. These people should handle the seeds with care when preparing the seeds for consumption, wearing disposable gloves. The symptoms are allergic contact
dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...
, or
blister A blister is a small pocket of body fluid (lymph, serum, plasma, blood, or pus) within the upper layers of the skin, usually caused by forceful rubbing (friction), burning, freezing, chemical exposure or infection. Most blisters are filled wi ...
s similar to that caused by contact with poison ivy.


Medical research

Although
extract An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts, h ...
s of ''Ginkgo biloba'' leaf are often marketed as cognitive enhancers, there is no evidence for effects on memory or attention in healthy people.
Systematic review A systematic review is a Literature review, scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from publ ...
s have shown there is no evidence for effectiveness of ginkgo in treating
high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...
,
menopause Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often ...
-related cognitive decline,
tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...
, post- stroke recovery, or
altitude sickness Altitude sickness, the mildest form being acute mountain sickness (AMS), is the harmful effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation. People can respond to high altitude in different ways. Sympt ...
. There is weak preliminary evidence for ginkgo affecting
dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
and
tardive dyskinesia Tardive dyskinesia (TD) is a disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips. Additionally, there may be rapid jerking movements or slow writhing movemen ...
symptoms in people with
schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...
.


Adverse effects

Side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s of using ginkgo supplements may include increased risk of bleeding, gastrointestinal discomfort,
nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
,
vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...
,
diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...
, headaches, dizziness, heart
palpitation Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart. Symptoms include a rapi ...
s, and restlessness. Although use of
standardized Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...
''Ginkgo biloba'' leaf extracts in moderate amounts appears to be safe, excessive use may have undesirable effects, especially in terms of
drug interaction Drug interactions occur when a drug's mechanism of action is disturbed by the concomitant administration of substances such as foods, beverages, or other drugs. The cause is often the inhibition of the specific receptors available to the drug, ...
s. The dosing of anticoagulants, such as
warfarin Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent st ...
or antiplatelet medication, may be adversely affected by using ginkgo supplements. According to a
systemic review A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on t ...
, the effects of ginkgo on pregnant women may include increased
bleeding time Bleeding time is a medical test done on someone to assess their platelets function. It involves making a patient bleed, then timing how long it takes for them to stop bleeding using a stopwatch or other suitable devices. The term template bleedin ...
, and there is inadequate information about safety during
lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...
. Ginkgo
pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
may produce
allergic reaction Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
s. ''Ginkgo biloba'' leaves and
sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument In biology, an integu ...
contain ginkgolic acids which are highly
allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...
ic long-chain alkylphenols, such as
bilobol Bilobol is an alkylresorcinol, a type of phenolic lipids composed of long aliphatic chains and phenolic rings. Chemically, it is similar in structure to urushiol, the irritant found in poison ivy; it is a strong skin irritant itself. Natura ...
or
adipostatin A Adipostatin A is an alkylresorcinol, a type of phenolic lipids composed of long aliphatic chains and phenolic rings. Chemically, it is similar in structure to urushiol, the irritant found in poison ivy. Adipostatin A can be found in ''Gingko ...
(bilobol is a substance related to anacardic acid from
cashew nut The cashew tree (''Anacardium occidentale'') is a tropical evergreen tree native to South America in the genus ''Anacardium'' that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as , but the dwarf cult ...
shells and
urushiol Urushiol is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae, especially '' Toxicodendron'' ''spp.'' (e.g., poison oak, Chinese lacquer tree, poison ivy, poison sumac), ''Comoclad ...
s present in poison ivy and other ''
Toxicodendron ''Toxicodendron'' is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oi ...
'' spp.) Individuals with a history of strong allergic reactions to poison ivy, mangoes, cashews and other alkylphenol-producing plants are more likely to experience an allergic reaction when consuming non-standardized ginkgo-containing preparations. The level of these allergens in standardized pharmaceutical preparations from ''Ginkgo biloba'' was restricted to 5 ppm by the
Commission E The German ''Commission E'' is a scientific advisory board of the Federal Institute for Drugs and Medical Devices formed in 1978. The commission gives scientific expertise for the approval of substances and products previously used in traditional, ...
of the former Federal German Health Authority. Overconsumption of seeds from ''Ginkgo biloba'' can deplete vitamin B6.


Traditional medicine

Ginkgo has been used in
traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action ...
since at least the 11th century C.E. Ginkgo seeds, leaves, and nuts have traditionally been used to treat various ailments, such as dementia, asthma, bronchitis, and kidney and bladder disorders. However, there is no conclusive evidence that ginkgo is useful for any of these conditions., s.v. ''Ginkgo biloba'' The
European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of medicinal products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products or Euro ...
Committee on Herbal Medicinal Products The Committee on Herbal Medicinal Products (HMPC), is the European Medicines Agency's committee A committee or commission is a body of one or more persons subordinate to a deliberative assembly. A committee is not itself considered to be a for ...
concluded that medicines containing ginkgo leaf can be used for treating mild age-related
dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
and mild
peripheral vascular disease Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular dise ...
in adults after serious conditions have been excluded by a physician.


Society and culture

The ginkgo leaf is the symbol of the
Urasenke is one of the main schools of Japanese tea ceremony. Along with and , it is one of the three lines of the family descending from , which together are known as the - or the "three houses/families" (). The name , literally meaning "rear hous ...
school of
Japanese tea ceremony The Japanese tea ceremony (known as or ) is a Japanese cultural activity involving the ceremonial preparation and presentation of , powdered green tea, the procedure of which is called . While in the West it is known as "tea ceremony", it is se ...
. The tree is the official tree of the Japanese capital of
Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
, and the symbol of Tokyo is a ginkgo leaf. Since 1948, the badge of
Tokyo University , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...
has been two ginkgo leaves (designed by Shoichi Hoshino), which became the university logo in 2004 with a redesign. The logo of
Osaka University , abbreviated as , is a public research university located in Osaka Prefecture, Japan. It is one of Japan's former Imperial Universities and a Designated National University listed as a "Top Type" university in the Top Global University Project. ...
has been a simplified ginkgo leaf since 1991 when designer Ikko Tanaka created it for the university's sixtieth anniversary.


Gallery

File:Ginkgo Tree Ginkgo biloba Trunk Bark 2000px.jpg, Trunk bark File:Ginkgo-biloba-male.JPG, Ginkgo pollen-bearing cones File:Ginko bud.jpg, Bud in spring File:GingkoFruitingTwigSpring.jpg, Ovules ready for fertilization File:Ginkgo embryo and gametophyte.jpg, Female gametophyte, dissected from a seed freshly shed from the tree, containing a well-developed embryo File:Ginkgo biloba0.jpg, Immature ginkgo ovules and leaves File:Gingko fg01.jpg, Autumn leaves and fallen seeds File:GinkgoSaplings.jpg, A forest of saplings sprout among last year's seeds File:2014-11-02 12 06 44 Ginkgo during autumn at the Ewing Presbyterian Church Cemetery in Ewing, New Jersey.jpg, Ginkgo tree in autumn File:2014-11-02 12 13 29 Ginkgo foliage and fruit during autumn at the Ewing Presbyterian Church Cemetery in Ewing, New Jersey.JPG, Seeds on tree File:Ginko biloba leaves.jpg, Ginkgo biloba leaves File:Ginkgo biloba. filare.jpg, Ginkgo in autumn in Florence (Italy)


See also

*
André Michaux André Michaux, also styled Andrew Michaud, (8 March 174611 October 1802) was a French botanist and explorer. He is most noted for his study of North American flora. In addition Michaux collected specimens in England, Spain, France, and even Per ...
, introduced the ginkgo to
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
* '' Bartheletia paradoxa'', a unique species of fungus that grows exclusively on ''Ginkgo'' leaves *
Ginkgo Petrified Forest State Park Ginkgo Petrified Forest State Park/Wanapum Recreational Area is a geologic preserve and public recreation area covering on the western shoreline of the Columbia River's Wanapum Reservoir at Vantage, Washington. Petrified wood was discovered in t ...
in central
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
, United States *
Herbalism Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern reme ...
* List of edible seeds


References


External links


Ginkgoopsida, Ginkgoales, Ginkgoaceae, Ginkgo biloba (ginkgo) description
The Gymnosperm Database
''Ginkgo biloba'' information
Plants for a Future Plants For A Future (PFAF) is an online not for profit resource for those interested in edible and useful plants, with a focus on temperate regions. The organization's emphasis is on perennial plants, named after the phrase "plans for a future" as ...
Plant Database
''Ginkgo biloba''
PlantUse English {{Authority control biloba CYP3A4 inhibitors Dioecious plants Edible plants Endangered plants Endemic flora of China Extant Ypresian first appearances Flora of Zhejiang Garden plants of Asia Medicinal plants of Asia Plants used in Ayurveda Plants used in bonsai Plants used in traditional Chinese medicine Taxa named by Carl Linnaeus Trees of China