Editing Ginkgoales

{{Short description|Order of plants}}
{{Use dmy dates|date=June 2024}}
{{Automatic taxobox
| fossil_range = {{fossil range|Asselian|0|[[Permian]]–[[Holocene|present]]}}
| image = Fossil Ginkgoales.jpg
| image_caption = Leaves and seeds of ''[[Ginkgo yimaensis]]'' (left) ''[[Yimaia|Yimaia recurva]]'' (top right) and ''[[Karkeniaceae|Karkenia henanensis]]'' (bottom right)
| display_parents = 3
| taxon = Ginkgoales
| authority = Gorozhankin, 1904
| subdivision_ranks = Families
| subdivision = *[[Ginkgoaceae]]
*{{Extinct}}[[Karkeniaceae]]
*{{Extinct}}[[Umaltolepidaceae]]
*{{Extinct}}[[Yimaiaceae]]
*{{Extinct}}[[Schmeissneriaceae]]
*{{Extinct}}[[Hamshawviaceae]] (sometimes placed in its own order)
*''Unnassigned to family''
**†''[[Ginkgoites]]'' (leaves)
**†''[[Sphenobaiera]]'' (leaves)
**†''[[Baiera]]'' (leaves)
**†''[[Glossophyllum]]'' (leaves)
**†''[[Trichopitys]]'' (ovulate organ)
**†''[[Stachyopitys]]'' (pollen organ)
}}

'''Ginkgoales''' are a [[gymnosperm]] [[Order (biology)|order]] containing only one [[Neontology|extant]] species: ''[[Ginkgo biloba]]'', the ginkgo tree.<ref>Christenhusz, M.{{nbsp}}J.{{nbsp}}M., J.{{nbsp}}L. Reveal, A.{{nbsp}}Farjon, M.{{nbsp}}F. Gardner, R.{{nbsp}}R. Mill, and M.{{nbsp}}W. Chase (2011). A new classification and linear sequence of extant gymnosperms. ''Phytotaxa'' 19:55–70. http://www.mapress.com/phytotaxa/content/2011/f/pt00019p070.pdf</ref> The order has a long fossil record extending back to the [[Early Permian]] around 300 million years ago from fossils found worldwide. The [[Order (biology)|order]] was a common component of [[Permian]] and [[Triassic]] flora before the super dominance of [[Conifer|conifers]]. 

== Evolution ==
Ginkgophyta and [[Cycad]]ophyta have a very ancient divergence dating to the early [[Carboniferous]].<ref>{{Cite journal|last1=Stull|first1=Gregory W.|last2=Qu|first2=Xiao-Jian|last3=Parins-Fukuchi|first3=Caroline|last4=Yang|first4=Ying-Ying|last5=Yang|first5=Jun-Bo|last6=Yang|first6=Zhi-Yun|last7=Hu|first7=Yi|last8=Ma|first8=Hong|last9=Soltis|first9=Pamela S.|last10=Soltis|first10=Douglas E.|last11=Li|first11=De-Zhu|date=19 July 2021|title=Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms|url=https://www.nature.com/articles/s41477-021-00964-4|journal=Nature Plants|language=en|volume=7|issue=8|pages=1015–1025|doi=10.1038/s41477-021-00964-4|pmid=34282286 |s2cid=236141481 |issn=2055-0278}}</ref> The earliest representative of the group in the fossil record is probably ''[[Trichopitys]]'' from the [[Asselian]] (299-293 million years ago) of France. The earliest representatives of ''[[Ginkgo]]'', represented by reproductive organs similar to the living species, first appear in the Middle Jurassic, alongside other, related forms such as ''[[Yimaia]]'' and ''[[Karkenia]]'', which have differently arranged reproductive structures and seeds associated with ''Ginkgo''-like leaves.<ref>{{Cite journal|last=Zhou|first=Zhi-Yan|date=March 2009|title=An overview of fossil Ginkgoales|url=https://linkinghub.elsevier.com/retrieve/pii/S1871174X0900002X|journal=Palaeoworld|language=en|volume=18|issue=1|pages=1–22|doi=10.1016/j.palwor.2009.01.001}}</ref><ref name=":0">{{Cite book|title=Paleobotany, Second Edition: The Biology and Evolution of Fossil Plants|last1=Taylor|first1=Thomas N.|last2=Taylor|first2=Edith L.|last3=Krings|first3=Michael|date=29 December 2008|publisher=Academic Press|isbn=9780123739728|edition=2nd|language=en}}</ref> The diversity of Ginkgoales declined during the Late Cretaceous and Cenozoic, coincident with the rise of flowering plants, with all Ginkgophytes aside from ''Ginkgo'' being extinct by the end of the Cretaceous.<ref name=":1">{{Cite journal|url=http://accessscience.com/content/289700|title=Ginkgoales|last=Beck|first=Charles|date=2014|website=Access Science|doi=10.1036/1097-8542.289700 |access-date=13 April 2017}}</ref><ref name=":0" /> The only remaining Ginkgophyte was ''Ginkgo adiantoides'' – a polymorphic species.<ref name=":2">{{Cite web|url=http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgo.html|title=Introduction to the Ginkgoales|author=Jalalpour, Julie|author2=Malkin, Matt|author3=Poon, Peter|author4=Rehrmann, Liz|author5=Yu, Jerry|date=1997|website=www.ucmp.berkeley.edu|access-date=20 April 2017}}</ref> Modern ''Ginkgo'' trees are native to China.<ref name=":1" />

== Reproduction ==
''Ginkgo'' trees produce ovulate and pollen-bearing structures. These structures are [[dioecious]], in that male and female structures come from different ''Ginkgo'' plants.<ref name=":1" /> The pollen organs are very similar to angiospermous [[catkins]]. They come from the [[axils]] of the bud scales, and the leaves from the ''Ginkgo'' tree spur shoots. Pollen is contained in sacs of two to four at the tips of sporophylls on the strobiloid. Ovules of ''Ginkgo'' trees come from stalks from leaf axils on the short shoots, each containing two ovules. The ovule is fertilized by the flagellated male gametes, which can move about freely. This fertilization process begins on the tree itself in the spring. The swollen fruit-like [[ovules]], about 2–3&nbsp;cm in diameter, fall from the tree in the fall, and fertilization continues into the winter/spring.<ref name=":0" /><ref name=":2" />  This ovule contains a single large seed, similar to that of a [[cycad]].<ref name=":0" />

== Morphology ==

=== Ginkgophyte wood ===
Fossils that appear ''Ginkgo''-like are filed under a [[morphogenus]] called ''Ginkgoxylon, Ginkgomyeloxylon,'' or ''Protoginkgoxylon''. Fossilized ginkgophyte wood is not commonly found in the record, possibly because it degrades easily, and possibly because it is difficult to tell apart from the much more pervasive [[conifer]] samples.<ref name=":0" /> Like conifer wood, it has secondary thin-walled xylem and a primary vascular system composed of eustele and bifacial vascular [[cambium]].  The tracheids in the secondary [[xylem]] rays have pitting that occurs only on the walls and is circularly bordered.<ref name=":1" />
[[File:Live reconstruction of Cretophasmomima melanogramma - journal.pone.0091290.g007.png|thumb|220x220px|This recreation displays one example of early Gingkophyte foliage.]]

=== Ginkgophyte foliage ===
''Ginkgophyte'' [[foliage]] has stayed largely consistent since the [[Mesozoic]].  Its historically wide territory makes it an important leaf morphology, and its unique [[stomata]] and isotopic profile give it a key role in recreations of the Mesozoic and [[Cenozoic]].  Leaf fossils that resemble the Ginkgophytes are known as ''[[Ginkgoites]]''.  There are similar, now extinct, morphogens, such as ''Sphenobaiera'', which describes fan-shaped, deeply divided leaves without clear [[petiole (botany)|petiole]]s.

The distinctive shape of the modern ''Ginkgo biloba'' gives the impression of a very narrow leaf morphology, but the group is varied and diverse.  The genus ''Ginkgo'' by itself contains a range of morphologies.  ''Ginkgo digitata'', from the [[Jurassic]], has long, wedge-shaped [[lamina (leaf)|lamina]]e with the intercostal regions covered in stomata and resin bodies, while ''G. pluripartita'' has at most 2&nbsp;cm-long leaves and is intercostally [[hypostomatic]].<ref name=":0" />

== Fossil gallery ==

<gallery widths="190px" heights="170px" perrow="3"> 
File:Ginkgo biloba leaf 01.jpg|A 6.7&nbsp;cm tall ''Ginkgo biloba'' leaf, with insect herbivory. [[Klondike Mountain Formation]], Republic, Ferry County, Washington, USA, [[Eocene]], [[Ypresian]], 49 million years old

File:Ginkgo biloba 01 SR 87-36-02 A.jpg| A 70&nbsp;mm-wide ''Ginkgo biloba'' leaf. Klondike Mountain Formation, Republic, Ferry County, Washington, USA, Eocene, Ypresian, 49 million years old

File:Ginkgo biloba MacAbee BC.jpg|''Ginkgo biloba'' [[Eocene]] fossil leaf from the Tranquille Shale of MacAbee, British Columbia, Canada

File:Ginkgo huttoni.jpg|Fossil of ''Ginkgo huttoni''. Photo taken at Naturalis Museum in [[Leiden]], The Netherlands.

File:Ginkgo huttoni 1.jpg|Fossil of ''[[Ginkgoites]] huttoni''
</gallery>

==References==
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{{Plant classification}}
{{Life on Earth}}
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[[Category:Ginkgophyta|.]]
[[Category:Gymnosperm orders]]
[[Category:Jurassic plants]]
[[Category:Extant Permian first appearances]]