Difference between revisions of "Equisetum"

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{{Redirect|Horsetail|other uses|Horse tail (disambiguation)}}
 
 
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| fossil_range = {{fossilrange|164.7|0|[[Callovian]]<ref>{{cite journal | url = http://www.amjbot.org/cgi/content/abstract/98/4/680 | journal= American Journal of Botany |DOI= 10.3732/ajb.1000211 | pmid=21613167 | volume=98 | issue=4 | title=''Equisetum thermale'' sp. nov. (Equisetales) from the Jurassic San Agust&iacute;n hot spring deposit, Patagonia: anatomy, paleoecology, and inferred paleoecophysiology |date=April 2011 | pages=680–97}}</ref>-[[Holocene]]}}
 
| fossil_range = {{fossilrange|164.7|0|[[Callovian]]<ref>{{cite journal | url = http://www.amjbot.org/cgi/content/abstract/98/4/680 | journal= American Journal of Botany |DOI= 10.3732/ajb.1000211 | pmid=21613167 | volume=98 | issue=4 | title=''Equisetum thermale'' sp. nov. (Equisetales) from the Jurassic San Agust&iacute;n hot spring deposit, Patagonia: anatomy, paleoecology, and inferred paleoecophysiology |date=April 2011 | pages=680–97}}</ref>-[[Holocene]]}}
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| type_species_authority = [[L.]]
 
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'''''Equisetum''''' ({{IPAc-en|ˌ|ɛ|k|w|ᵻ|ˈ|s|iː|t|əm}}; '''horsetail''', '''snake grass''', '''puzzlegrass''') is the only living [[genus]] in [[Equisetaceae]], a [[family (biology)|family]] of [[vascular plant]]s that reproduce by [[spore]]s rather than seeds.<ref>''Sunset Western Garden Book,'' 1995:606–607</ref>
 
 
''Equisetum'' is a "[[living fossil]]" as it is the only living genus of the entire [[class (biology)|class]] [[Equisetopsida]], which for over one hundred million years was much more diverse and dominated the [[understory]] of late [[Paleozoic]] forests. Some Equisetopsida were large [[tree]]s reaching to 30 meters tall.<ref>{{cite web|url=http://www.fiu.edu/~chusb001/GiantEquisetum/Intro_Equisetum.html |publisher=[[Florida International University]] |title=An Introduction to the Genus ''Equisetum'' and the Class Sphenopsida as a whole |accessdate=2009-07-22 |deadurl=yes |archiveurl=https://web.archive.org/web/20090714050011/http://www.fiu.edu/~chusb001/GiantEquisetum/Intro_Equisetum.html |archivedate=2009-07-14 |df= }}</ref> The genus ''[[Calamites]]'' of the family [[Calamitaceae]], for example, is abundant in [[coal]] deposits from the [[Carboniferous]] period. The pattern of spacing of nodes in horsetails, wherein those toward the apex of the shoot are increasingly close together, inspired [[John Napier]] to invent [[logarithm]]s.<ref>{{cite journal|last=Sacks|first=Oliver|title=Field Trip: Hunting Horsetails|journal=The New Yorker|date=August 2011}}</ref>
 
 
A superficially similar but entirely unrelated [[flowering plant]] genus, mare's tail (''[[Hippuris]]''), is occasionally referred to as "horsetail", and adding to confusion, the name mare's tail is sometimes applied to ''Equisetum''.<ref>{{cite book|title=Oxford English Dictionary}}</ref>
 
 
Despite centuries of use in [[traditional medicine]], there is no evidence that ''Equisetum'' has any [[Evidence-based medicine|medicinal properties]].
 
 
==Etymology==
 
{{Refimprove|section|date=August 2018}}
 
The name "horsetail", often used for the entire group, arose because the branched species somewhat resemble a [[horse]]'s tail. Similarly, the [[Binomial nomenclature|scientific name]] ''Equisetum'' is derived from the [[Latin]] ''equus'' ("horse") + ''seta'' ("bristle").<ref>{{cite book |page= 283 |title= Florida Ethnobotany |author= Daniel F. Austin |edition= illustrated |publisher= CRC Press |year= 2004 |isbn= 9780203491881}}</ref>
 
 
Other names include '''candock''' for branching individuals, and '''snake grass''' or '''scouring-rush''' for unbranched or sparsely branched individuals. The latter name refers to the [[Juncus|rush]]-like appearance of the plants, and to the fact that the stems are coated with abrasive [[silicate]]s, making them useful for scouring (cleaning) metal items such as cooking pots or drinking mugs, particularly those made of [[tin]]. In [[German (language)|German]], the corresponding name is ''Zinnkraut'' ("tin-herb"). [[Equisetum hyemale|Rough horsetail ''E. hyemale'']] is still boiled and then dried in [[Japan]], to be used for the final polishing process on [[Woodworking|woodcraft]] to produce a smoother finish than any [[sandpaper]]. In [[Spanish (language)|Spanish]]-speaking countries, these plants are known as "cola de caballo," meaning "horsetail".
 
 
==Description==
 
In these plants the [[Leaf|leaves]] are greatly reduced and usually non-[[Photosynthesis|photosynthetic]]. They contain a single, non-branching [[vascular bundle|vascular trace]], which is the defining feature of [[microphyll]]s. However, it has recently been recognised that horsetail microphylls are probably not ancestral as in [[Lycopodiophyta]] (clubmosses and relatives), but rather derived [[adaptation]]s, evolved by reduction of [[wikt:megaphyll|megaphylls]].<ref>{{cite journal |last=Rutishauser |first=R |title=Polymerous leaf whorls in vascular plants: Developmental morphology and fuzziness of organ identities |journal=International Journal of Plant Sciences |volume=160 |issue=S6 |pages=S81–S103 |date=November 1999 |pmid=10572024 |doi=10.1086/314221}}</ref> They are, therefore, sometimes referred to as megaphylls to reflect this [[homology (biology)|homology]].
 
 
The leaves of horsetails are arranged in [[Whorl (botany)|whorls]] fused into [[node (botany)|nodal]] sheaths. The stems are usually green and photosynthetic, and are distinctive in being hollow, jointed and ridged (with sometimes 3 but usually 6–40 ridges). There may or may not be whorls of branches at the nodes.
 
 
[[Image:Horsetail vegeative stem.JPG|120px|thumb|Vegetative stem:<br/>B = branch in whorl<br/>I = internode<br/>L = leaves<br/>N = node]]
 
[[Image:Equisetum telmateia strob.jpg|thumb|Strobilus of [[Equisetum telmateia|Northern giant horsetail]] (''Equisetum telmateia'' subsp. ''braunii''), terminal on an unbranched stem.]]
 
[[Image:Microscopic view of Equisetum in Japan one 20thmm graduation.jpg|thumb|Microscopic view of [[Equisetum hyemale|rough horsetail]], ''Equisetum hyemale'' (2-1-0-1-2 is one [[millimetre]] with 1/20th [[Graduation (instrument)|graduation]]).<br/>The small white protuberances are accumulated [[silicate]]s on [[Cell (biology)|cell]]s.]]
 
 
===Spores===
 
The [[spore]]s are borne under [[sporangiophore]]s in [[strobilus|strobili]], cone-like structures at the tips of some of the stems. In many species the cone-bearing shoots are unbranched, and in some (e.g. [[Equisetum arvense|field horsetail]], ''E. arvense'') they are non-photosynthetic, produced early in spring. In some other species (e.g. [[Equisetum palustre|marsh horsetail]], ''E. palustre'') they are very similar to sterile shoots, photosynthetic and with whorls of branches.
 
 
Horsetails are mostly [[Spore|homosporous]], though in the field horsetail smaller spores give rise to male [[Prothallium|prothalli]]. The spores have four [[elater]]s that act as moisture-sensitive springs, assisting spore dispersal through crawling and hopping motions after the [[Sporangium|sporangia]] have split open longitudinally.<ref>{{Cite web|title = Horsetail plant spores use 'legs' to walk and jump – BBC News|url = https://www.bbc.com/news/science-environment-24025365|website = BBC News|accessdate = 2015-11-30|language = en-GB}}</ref>
 
 
===''Equisetum'' cell walls ===
 
The crude cell extracts of all ''Equisetum'' species tested contain [[mixed-linkage glucan : Xyloglucan endotransglucosylase]] (MXE) activity.<ref>{{Cite journal | last1 = Fry | first1 = S. C. | last2 = Mohler | first2 = K. E. | last3 = Nesselrode | first3 = B. H. W. A. | last4 = Frankov | first4 = L. | title = Mixed-linkage -glucan:xyloglucan endotransglucosylase, a novel wall-remodelling enzyme from ''Equisetum'' (horsetails) and charophytic algae | doi = 10.1111/j.1365-313X.2008.03504.x | journal = The Plant Journal | volume = 55 | issue = 2 | pages = 240–252 | year = 2008 | pmid = 18397375| pmc = }}</ref> This is a novel enzyme and is not known to occur in any other plants. In addition, the cell walls of all ''Equisetum'' species tested contain [[mixed-linkage glucan]] (MLG), a [[polysaccharide]] which, until recently, was thought to be confined to the [[Poales]].<ref>{{cite journal|pmid=18393951 | doi=10.1111/j.1469-8137.2008.02435.x|title=Mixed-linkage (1→3,1→4)-β-d-glucan is a major hemicellulose of ''Equisetum'' (horsetail) cell walls|year=2008|last1=Fry|first1=Stephen C.|last2=Nesselrode|first2=Bertram H. W. A.|last3=Miller|first3=Janice G.|last4=Mewburn|first4=Ben R.|journal=New Phytologist|volume=179|pages=104–15|issue=1}}</ref><ref>{{cite journal|pmid=18284587 | doi=10.1111/j.1365-313X.2008.03453.x|title=Mixed-linkage (1→3),(1→4)-β-d-glucan is not unique to the Poales and is an abundant component of ''Equisetum arvense'' cell walls|year=2008|last1=Sørensen|first1=Iben|last2=Pettolino|first2=Filomena A.|last3=Wilson|first3=Sarah M.|last4=Doblin|first4=Monika S.|last5=Johansen|first5=Bo|last6=Bacic|first6=Antony|last7=Willats|first7=William G. T.|journal=The Plant Journal|volume=54|issue=3|pages=510–21}}</ref> The evolutionary distance between ''Equisetum'' and the Poales suggests that each evolved MLG independently. The presence of MXE activity in ''Equisetum'' suggests that they have evolved MLG along with some mechanism of cell wall modification. The lack of MXE in the Poales suggests that there it must play some other, currently unknown, role. Due to the correlation between MXE activity and cell age, MXE has been proposed to promote the cessation of cell expansion.{{citation needed|date=August 2016}}
 
 
==Taxonomy==
 
 
===Species===
 
The living members of the genus ''Equisetum'' are divided into two distinct lineages, which are usually treated as [[Subgenus|subgenera]]. The name of the type subgenus, ''Equisetum'', means "horse hair" in [[Latin (language)|Latin]], while the name of the other subgenus, ''Hippochaete'', means "horse hair" in [[Greek (language)|Greek]]. [[Hybrid (biology)|Hybrid]]s are common, but hybridization has only been recorded between members of the same subgenus.<ref>{{Cite web
 
|url=http://www.btinternet.com/~pigott/equisetum/taxonsum.html|title=Summary of ''Equisetum'' Taxonomy|last=Pigott|first=Anthony|date=4 October 2001|website=National Collection of ''Equisetum''|archiveurl=https://web.archive.org/web/20121021201939/http://www.btinternet.com/~pigott/equisetum/taxonsum.html|archivedate=21 October 2012|deadurl=yes|accessdate=17 June 2013}}</ref>  While plants of subgenus ''Equisetum'' are usually referred to as horsetails, those of subgenus ''Hippochaete'' are often called scouring rushes, especially when unbranched.
 
 
Two ''Equisetum'' plants are sold commercially under the names ''Equisetum japonicum'' (barred horsetail) and ''Equisetum camtschatcense'' (Kamchatka horsetail). These are both types of ''E. hyemale'' var. ''hyemale'', although they may also be listed as varieties of ''E. hyemale''.{{citation needed|date=October 2016}}
 
 
[[Image:Equisetum hyemale 02 by Line1.jpg|thumb|right|[[Rough horsetail]] in [[Parc floral de Paris]]]]
 
;Subgenus ''Equisetum''
 
* {{tx|[[Equisetum arvense]]|[[Carl Linnaeus|L.]]}} – field horsetail, common horsetail or mare's tail; circumboreal down through temperate zones
 
* {{tx|[[Equisetum bogotense]]|[[Carl Sigismund Kunth|Kunth]]}} – Andean horsetail; upland South America up to Costa Rica; includes ''E. rinihuense'', sometimes treated as a separate species
 
* {{tx|[[Equisetum diffusum]]|L.}} – Himalayan horsetail; Himalayan India and China and adjacent nations above about 1500 feet (450 m)
 
* {{tx|[[Equisetum fluviatile]]|L.}} – water horsetail; circumboreal down through temperate zones
 
* {{tx|[[Equisetum palustre]]|L.}} – marsh horsetail; circumboreal down through temperate zones
 
* {{tx|[[Equisetum pratense]]|[[Jakob Friedrich Ehrhart|Ehrh.]]}} – meadow horsetail, shade horsetail, shady horsetail; circumboreal except for tundra down through cool temperate zones
 
* {{tx|[[Equisetum sylvaticum]]|L.}} – wood horsetail; circumboreal down through cool temperate zones, more restricted in east Asia
 
* {{tx|[[Equisetum telmateia]]|Ehrh.}} – great horsetail, northern giant horsetail; Europe to Asia Minor and north Africa, also west coast of North America
 
[[Image:Equisetum ramosissimum, Slavičín, Czech Republic.jpg|thumb|right|Branched horsetail (''[[Equisetum ramosissimum|E. ramosissimum]]'')]]
 
;Subgenus ''Hippochaete''
 
* {{tx|[[Equisetum giganteum]]|L.}} – southern giant horsetail or giant horsetail; temperate to tropical South America and Central America north to southern Mexico
 
* {{tx|[[Equisetum hyemale]]|L.}} – rough horsetail, rough scouring rush; most of non-tropical northern hemisphere
 
* {{tx|[[Equisetum laevigatum]]|A.Braun}} – smooth horsetail, smooth scouring rush; western 3/4 of North America down into northwestern Mexico; also sometimes known as ''Equisetum kansanum''
 
* {{tx|[[Equisetum myriochaetum]]|[[Diederich Franz Leonhard von Schlechtendal|Schltdl.]] & [[Adelbert von Chamisso|Cham.]]}} – Mexican giant horsetail; from central Mexico south to Peru
 
* {{tx|[[Equisetum ramosissimum]]|[[René Louiche Desfontaines|Desf.]]}} (including ''E.&nbsp;debile'') – branched horsetail; Asia, Europe, Africa, southwest Pacific islands
 
* {{tx|[[Equisetum scirpoides]]|[[André Michaux|Michx.]]}} – dwarf horsetail, dwarf scouring rush; northern (cool temperate) zones worldwide
 
* {{tx|[[Equisetum variegatum]]|[[Schleich.]] ex [[George Heinrich Weber|Weber]] & [[Charles Mohr|Mohr]]}} – variegated horsetail, variegated scouring rush; northern (cool temperate) zones worldwide, except for northeasternmost Asia
 
;unplaced to subgenus
 
 
*{{extinct}}''[[Equisetum dimorphum]]'' – [[Jurassic|Lower Jurassic]], Argentina
 
*{{extinct}}''[[Equisetum thermale]]'' – [[Jurassic|Middle to Late Jurassic]], Argentina
 
 
===Named hybrids===
 
[[Image:Equisetum x moorei3.JPG|thumb|right|''[[Equisetum × moorei]]'' ([[Rough Horsetail]] × [[Equisetum ramosissimum|Branched Horsetail]])]]
 
;Hybrids between species in subgenus ''Equisetum''
 
* [[Equisetum × bowmanii|''Equisetum'' × ''bowmanii'']] {{small|[[Christopher Nigel Page|C.N.Page]]}} (''Equisetum sylvaticum'' × ''Equisetum telmateia'')
 
* [[Equisetum × dycei|''Equisetum'' × ''dycei'']] {{small|C.N.Page}} (''Equisetum fluviatile'' × ''Equisetum palustre'')
 
* [[Equisetum × font-queri|''Equisetum'' × ''font-queri'']] {{small|[[Werner Rothmaler|Rothm.]]}} (''Equisetum palustre'' × ''Equisetum telmateia'')
 
* [[Equisetum × litorale|''Equisetum'' × ''litorale'']] {{small|Kühlew ex [[Franz Josef Ruprecht|Rupr.]]}} (''Equisetum arvense'' × ''Equisetum fluviatile'')
 
* [[Equisetum × mchaffieae|''Equisetum'' × ''mchaffieae'']] {{small|C.N.Page}} (''Equisetum fluviatile'' × ''Equisetum pratense'')
 
* [[Equisetum × mildeanum|''Equisetum'' × ''mildeanum'']] {{small|Rothm.}} (''Equisetum pratense'' × ''Equisetum sylvaticum'')
 
* [[Equisetum × robertsii|''Equisetum'' × ''robertsii'']] {{small|Dines}} (''Equisetum arvense'' × ''Equisetum telmateia'')
 
* [[Equisetum × rothmaleri|''Equisetum'' × ''rothmaleri'']] {{small|C.N.Page}} (''Equisetum arvense'' × ''Equisetum palustre'')
 
* [[Equisetum × willmotii|''Equisetum'' × ''willmotii'']] {{small|C.N.Page}} (''Equisetum fluviatile'' × ''Equisetum telmateia'')
 
;Hybrids between species in subgenus ''Hippochaete''
 
* [[Equisetum × ferrissii|''Equisetum'' × ''ferrissii'']] {{small|[[Willard Nelson Clute|Clute]]}} (''Equisetum hyemale'' × ''Equisetum laevigatum'')
 
* [[Equisetum × moorei|''Equisetum'' × ''moorei'']] {{small|[[Edward Newman (entomologist)|Newman]]}} (''Equisetum hyemale'' × ''Equisetum ramosissimum'')
 
* [[Equisetum × nelsonii|''Equisetum'' × ''nelsonii'']] {{small|([[Alvah Augustus Eaton|A.A.Eaton]]) Schaffn.}} (''Equisetum laevigatum'' × ''Equisetum variegatum'')
 
* [[Equisetum × schaffneri|''Equisetum'' × ''schaffneri'']] {{small|Milde}} (''Equisetum giganteum'' × ''Equisetum myriochaetum'')
 
* [[Equisetum x trachyodon|''Equisetum'' × ''trachyodon'']] {{small|(A.Braun) W.D.J.Koch}} (''Equisetum hyemale'' × ''Equisetum variegatum'')
 
 
==Distribution and ecology==
 
 
The genus ''Equisetum'' as a whole, while concentrated in the non-tropical northern hemisphere, is near-[[cosmopolitan distribution|cosmopolitan]], being absent only from [[Antarctica]], though they are not known to be native to Australia, New Zealand nor the islands of the Pacific. They are most common in northern North America (Canada and the northernmost United States), where the genus is represented by nine species (''arvense'', ''fluviatile'', ''palustre'', ''pratense'', ''sylvaticum'', ''hyemale'', ''laevigatum'', ''scirpoides'', and ''variegatum''). Only four (''bogotense'', ''giganteum'', ''myriochaetum'', and ''ramosissimum'') of the fifteen species are known to be native south of the Equator. They are [[perennial plant]]s, [[Herbaceous plant|herbaceous]] and dying back in winter as most temperate species, or [[evergreen]] as most tropical species and the temperate species [[Equisetum hyemale|rough horsetail]] (''E. hyemale''), branched horsetail (''[[Equisetum ramosissimum|E. ramosissimum]]''), dwarf horsetail (''[[Equisetum scirpoides|E. scirpoides]]'') and [[Equisetum variegatum|variegated horsetail]] (''E. variegatum''). They typically grow 0.2–1.5 m tall, though the "giant horsetails" are recorded to grow as high as 2.5 m ([[Equisetum telmateia|northern giant horsetail]], ''E. telmateia''), 5 m ([[Equisetum giganteum|southern giant horsetail]], ''E. giganteum'') or 8 m ([[Equisetum myriochaetum|Mexican giant horsetail]], ''E. myriochaetum''), and allegedly even more.<ref>Husby, Chad E. (2003): [http://www.fiu.edu/~chusb001/giant_equisetum.html How large are the giant horsetails]? Version of 2003-03-19. Retrieved 2008-11-20. {{webarchive |url=https://web.archive.org/web/20040404033635/http://www.fiu.edu/~chusb001/giant_equisetum.html |date=April 4, 2004 }}</ref>
 
 
One species, ''[[Equisetum fluviatile]]'', is an emergent [[Aquatic plant|aquatic]], rooted in water with shoots growing into the air. The stalks arise from [[rhizome]]s that are deep underground and difficult to dig out. The [[Equisetum arvense|field horsetail]] (''E. arvense'') can be a nuisance [[weed]], readily regrowing from the rhizome after being pulled out. It is unaffected by many [[herbicide]]s{{which|date=August 2016}} designed to kill [[Spermatophyte|seed plants]].{{citation needed|date=August 2016}} However, as ''E. arvense'' prefers an acid soil, [[Agricultural lime|lime]] may be used to assist in eradication efforts to bring the soil [[pH]] to 7 or 8.<ref>Kress, Henriette, [http://www.henriettesherbal.com/blog/getting-rid-horsetail.html Getting rid of horsetail], Henriette's Herbal Homepage, April 7th, 2005. Retrieved May 19, 2010.</ref> Members of the genus have been declared noxious weeds in [[Australia]] and in the US state of [[Oregon]].<ref name=aus>{{cite book|title=Noxious weeds of Australia|url=https://books.google.com/books?id=sRCrNAQQrpwC&pg=PA14&dq=Equisetum+australia&q=Equisetum%20australia|publisher=CSIRO Publishing |year=2001|page=14|author1=William Thomas Parsons |author2=Eric George Cuthbertson |isbn=978-0-643-06514-7}}</ref><ref>{{cite web|title=''Equisetum telmateia'' Ehrh. giant horsetail|url=http://plants.usda.gov/java/profile?symbol=EQTE|publisher=[[USDA]]|accessdate=2010-05-18}}</ref>
 
 
All the ''Equisetum'' are classed as "unwanted organisms" in [[New Zealand]] and are listed on the [[National Pest Plant Accord]].{{citation needed|date=May 2018}}
 
 
==Consumption==
 
 
People have regularly consumed horsetails. The young plants are eaten cooked or raw, but considerable care must be taken.<ref name=drugs/> For example, the fertile stems bearing [[strobili]] of some species are cooked and eaten like asparagus (a dish called ''tsukushi''<ref>Michael Ashkenazi, Jeanne Jacob. 2003. Food culture in Japan. Greenwood Publishing Group. 232 p.</ref>) in [[Japan]].<ref>[http://www.pfaf.org/user/DatabaseSearhResult.aspx Plants For A Future Database.]</ref> Native Americans in the [[Pacific Northwest]] eat the young shoots of this plant raw.<ref>Erna Gunther. 1973. ''Ethnobotany of western Washington: The knowledge and use of indigenous plants by Native Americans''.</ref><ref>Robin Harford [https://www.eatweeds.co.uk/field-horsetail-edible Is field-horsetail edible]</ref>
 
 
If eaten over a long enough period of time, some species of horsetail can be [[poison]]ous to grazing animals, including [[List of plants poisonous to equines|horses]].<ref>Israelsen, Clark E.; McKendrick, Scott S. & Bagley, Clell V. (2006): Poisonous Plants and Equine. [http://www.msuextension.org/ruralliving/Dream/PDF/Equine_poison.pdf PDF fulltext] {{webarchive |url=https://web.archive.org/web/20110112023355/http://www.msuextension.org/ruralliving/Dream/PDF/Equine_poison.pdf |date=January 12, 2011 }}</ref> The toxicity appears to be due to [[thiaminase]], which can cause thiamin (vitamin B1) deficiency.<ref name="drugs">{{cite web|title=Horsetail|url=https://www.drugs.com/npp/horsetail.html|publisher=Drugs.com|accessdate=19 August 2018|date=11 June 2018}}</ref><ref name=NIH/><ref name=Henderson>{{cite journal |vauthors=Henderson JA, Evans EV, McIntosh RA |title=The antithiamine action of ''Equisetum'' |journal=Journal of the American Veterinary Medical Association |volume=120 |issue=903 |pages=375–8 |date=June 1952 |pmid=14927511}}</ref><ref name=Fabre>{{cite journal|last=Fabre|first=B|last2=Geay |first2=B. |last3=Beaufils |first3=P. |title=Thiaminase activity in ''Equisetum arvense'' and its extracts.|journal=Plant Med Phytother|year=1993|volume=26|pages=190–7.}}</ref>
 
 
==Folk medicine and safety concerns==
 
Extracts and other preparations of ''E. arvense'' have served as [[traditional medicine|herbal remedies]], with records dating over centuries.<ref name=drugs/><ref name="NIH">{{cite web |url=https://www.nlm.nih.gov/medlineplus/druginfo/natural/843.html|title=Horsetail|publisher=MedlinePlus, US National Library of Medicine, National Institutes of Health|date=8 December 2017|accessdate=14 November 2013}}</ref><ref name="sarris">{{cite journal|pmc=5295114|year=2017|author1=Dragos|first1=D|title=Phytomedicine in Joint Disorders|journal=Nutrients|volume=9|issue=1|pages=70|last2=Gilca|first2=M|last3=Gaman|first3=L|last4=Vlad|first4=A|last5=Iosif|first5=L|last6=Stoian|first6=I|last7=Lupescu|first7=O|doi=10.3390/nu9010070}}</ref> In 2009, the [[European Food Safety Authority]] concluded there was no evidence for [[health claim|health effects]] of ''E. arvense'', such as for invigoration, weight control, skincare, hair health, and bone health.<ref name ="efsa">{{Cite journal|url=https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2009.1289|title=Scientific opinion on the substantiation of health claims related to ''Equisetum arvense'' L. and invigoration of the body (ID 2437), maintenance of skin (ID 2438), maintenance of hair (ID 2438), maintenance of bone (ID 2439), and maintenance or achievement of a normal body weight (ID 2783) pursuant to Article 13 of Regulation (EC) No 1924/2006|journal=EFSA Journal|volume=7|issue=10|pages=1289|accessdate=2013-10-09|publisher=[[European Food Safety Authority]]|doi=10.2903/j.efsa.2009.1289|year=2009}}</ref> {{As of|2018}}, there is insufficient scientific evidence for its effectiveness as a medicine to treat any human condition.<ref name=drugs/><ref name=sarris/><ref name=efsa/>
 
 
''E. arvense'' contains [[thiaminase]], which metabolizes the [[B vitamin]], [[thiamin]], potentially causing [[thiamin deficiency]] if taken chronically.<ref name=NIH/> Horsetail might produce an effect like a water-eliminating pill or "diuretic."<ref name=NIH/> However, it has no demonstrated safety evidence and may be toxic, especially to children and pregnant women.<ref name=drugs/>
 
 
==See also==
 
* [[List of plants poisonous to equines]]
 
{{Clear}}
 
  
 
==References==
 
==References==
 
{{Reflist|2}}
 
{{Reflist|2}}
  
==Further reading==
+
[[Category:Ferns]]
* [http://internationalequisetologicalassociation.yolasite.com/taxonomy.php Walkowiak, Radoslaw (2008): ''IEA'' –p ''Equisetum'' Taxonomy]
+
[[Category:Plants for Keenan to eat]]
* [http://www.ville-ge.ch/mhng/paleo/paleo-pdf/24-1/pal-24-1-16.pdf Weber, Reinhard (2005): ''Equisetites aequecaliginosus'' sp. nov., ein Riesenschachtelhalm aus der spättriassischen] Formation Santa Clara, Sonora, Mexiko; ''Equisetites aequecaliginosus'' sp. nov., a tall horsetail from the Late Triassic Santa Clara Formation, Sonora, Mexico ''Revue de Paléobiologie'' '''24'''(1): 331–364 (German, English abstract)
 
 
 
==External links==
 
* [http://tolweb.org/Equisetum/33130/ ''Equisetum''] at the Tree of Life Web Project
 
* [http://equisetum.org/ National Collection of ''Equisetum'']
 
* [http://www.matus.at/ The Wonderful World of Equisetum]
 
* [http://internationalequisetologicalassociation.yolasite.com/ International Equisetological Association]
 
* {{Cite EB1911|wstitle=Horsetail|short=x}}
 
 
 
{{Commons category|Equisetaceae}}
 
{{Wikispecies}}
 
{{Taxonbar|from=Q28114}}
 
 
 
[[Category:Equisetum| ]]
 
[[Category:Living fossils]]
 
[[Category:Pteridophyta genera]]
 
[[Category:Flora of Europe]]
 
[[Category:Flora of Africa]]
 
[[Category:Flora of Asia]]
 
[[Category:Flora of North America]]
 
[[Category:Flora of South America]]
 
[[Category:Flora of Australasia]]
 
[[Category:Medicinal plants]]
 
[[Category:Extant Middle Jurassic first appearances]]
 
[[Category:Callovian first appearances]]
 
[[Category:Callovian genus first appearances]]
 
[[Category:Taxa named by Carl Linnaeus]]
 

Revision as of 15:08, 13 September 2018

Equisetum
Temporal range: Callovian[1]-Holocene
Equisetopsida.jpg
"Candocks" of the great horsetail (Equisetum telmateia subsp. telmateia), showing whorls of branches and the tiny dark-tipped leaves
Scientific classification e
Kingdom: Plantae
Division: Pteridophyta
Class: Equisetopsida
Order: Equisetales
Family: Equisetaceae
Genus: Equisetum
L.
Type species
Equisetum arvense
Species

See text

References