View source for Polygonum

{{Short description|Genus of flowering plants in the knotweed family Polygonaceae}}
{{Distinguish|Polygonatum}}
{{Automatic taxobox
|image = Polygonum aviculare 4.JPG
|image_caption = ''[[Polygonum aviculare]]''
|taxon = Polygonum
|authority = [[Carl Linnaeus|L.]]
|subdivision_ranks = Species
|subdivision = See text.
}}

'''''Polygonum''''' is a [[genus]] of about 130 species of [[flowering plants]] in the buckwheat and knotweed family [[Polygonaceae]]. Common names include '''knotweed''' and '''knotgrass''' (though the common names may refer more broadly to plants from [[Polygonaceae]]). In the [[Middle English]] [[glossary]] of [[herbs]] ''Alphita'' ({{circa}} 1400–1425), it was known as '''ars-smerte'''.<ref>Middle English Dictionary</ref>{{CN|date=September 2024|reason = Arse-smart is just one species, water pepper, Polygonum hydropiper (now Persicaria hydropiper). Named because it stings tender skin when used in bedding to deter fleas and lice.  Need more detailed ref to justify its historical application to the whole genus.)}} There have been various opinions about how broadly the genus should be defined. For example, [[buckwheat]] (''Fagopyrum esculentum'') has sometimes been included in the genus as ''Polygonum fagopyrum''. Former genera such as '''''Polygonella''''' have been subsumed into ''Polygonum''; other genera have been split off.

The genus primarily grows in northern [[temperate]] regions. The species are very diverse, ranging from prostrate [[herbaceous]] [[annual plant]]s to erect herbaceous [[perennial plant]]s.

''Polygonum'' species are occasionally eaten by humans, and are used as food plants by the [[larva]]e of some [[Lepidoptera]] species – see list. Most species are considered weeds in Europe and North America.

==Description==
When the genus is defined narrowly, ''Polygonum'' species are [[Annual plant|annual]] or [[Perennial plant|perennial]] [[herbaceous plant]]s, rarely [[shrub]]by, with much branched stems. The leaves are arranged alternately, usually less than {{cvt|2|cm|in|1}} long, with a length greater than the width. They have a membranous [[ochrea]] (a sheath around the stem nodes). The flowers are usually [[Plant reproductive morphology#Bisexual|bisexual]], rarely [[Plant reproductive morphology#Unisexual|unisexual]], and have five (occasionally four) [[tepal]]s, the outer being slightly different from the inner ones. There are usually four to six [[stamen]]s and three (rarely two) [[Stigma (botany)#Style|style]]s. The fruit is three-sided.<ref name=NoguOrtiPaiv06>{{Citation |mode=cs1|last1=Nogueira |first1=I. |last2=Ortiz |first2=S. |last3=Paiva |first3=J.A.R. |date=2006 |contribution=''Polygonum'' L. |title=Flora Zambesiaca ''(online)'' |volume=9 |issue=3 |publisher=Royal Botanic Gardens, Kew |contribution-url=http://apps.kew.org/efloras/namedetail.do?qry=namelist&flora=fz&taxon=11692&nameid=29983 |access-date=2019-04-29 |name-list-style=amp}}</ref>

==Taxonomy==
The genus ''Polygonum'' was first described by [[Carl Linnaeus]] in 1754. The genus name is usually said to be from the [[Ancient Greek|Greek]] {{lang|grc|πολυ-}} (''poly''-, 'many') and {{lang|grc|γόνυ}} (''gonu'', 'knee' or 'joint'), in reference to the swollen jointed stem.<ref name=HyamPank95>{{Cite book |last1=Hyam |first1=R. |last2=Pankhurst |first2=R.J. |year=1995 |title=Plants and their names : a concise dictionary |location=Oxford |publisher=Oxford University Press |isbn=978-0-19-866189-4 |name-list-style=amp}} p. 404</ref><ref name=Coom94>{{Cite book |last=Coombes |first=Allen J. |year=1994 |title=Dictionary of Plant Names |location=London |publisher=Hamlyn Books |isbn=978-0-600-58187-1}} p. 148.</ref> However, long before Linnaeus, the name was used in Greek and Latin for a plant used medically. Discussing the plant he knew as ''polygonum'' in 1655, [[Matthias Martinius]] referred to [[Scribonius Largus]] (who wrote a list of prescriptions around 47 AD) and gave an alternative etymology, based on {{lang|grc|γόνος}} (''gonos'', 'offspring', 'seed'), the meaning of the name then being the Latin {{lang|la|foecundus}}, i.e. 'fecund', 'with many offspring'.<ref name=Mart55>{{Cite book|last1=Martinius |first1=Matthias |date=1655 |contribution=Polygonum |title=Lexicon Philologicum præcipue etymologicum et sacrum |publisher=T. M. Goetzenius |contribution-url=https://books.google.com/books?id=OhFmAAAAcAAJ&pg=PT1307 |access-date=2019-05-10 |language=la}}</ref> The ''Flora of North America'' says that a derivation meaning 'many seeds' is the "grammatically correct interpretation".<ref name="FNA">{{cite book |first1=Mihai |last1=Costea |first2=François J. |last2=Tardif |first3=Harold R. |last3=Hinds |contribution=Polygonum |contribution-url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=126398 |access-date=2019-05-10 |name-list-style=amp |editor-last=Flora of North America Editorial Committee <!--|year=1982 onwards -->|title=Flora of North America ''(online)'' |publisher=eFloras.org}}</ref>

Many members of the family [[Polygonaceae]] that are now placed in separate genera were at one time or other placed in ''Polygonum'', including species of ''[[Fagopyrum]]'', ''[[Fallopia]]'', ''[[Persicaria]]'' and ''[[Reynoutria]]'',<ref name=SchuReveBaylKron15/> and older sources frequently use much wider definitions of the genus. [[Molecular phylogenetics|Molecular phylogenetic]] studies, particularly in the 21st century, have led to major changes. Clarifying the [[Circumscription (taxonomy)|circumscription]] of genera split from ''Polygonum'' was described in 2015 as "still ongoing".<ref name=SchuReveBaylKron15/>

===Classification and phylogeny===
''Polygonum'' is placed in the tribe Polygoneae of the subfamily [[Polygonoideae]]. Within the tribe, it is most closely related to the genera ''[[Duma (plant)|Duma]]'' and ''[[Atraphaxis]]'', forming the so-called "DAP clade".<ref name=SchuReveBaylKron15>{{Citation |mode=cs1|last1=Schuster |first1=Tanja M. |last2=Reveal |first2=James L. |last3=Bayly |first3=Michael J. |last4=Kron |first4=Kathleen A. |date=2015 |title=An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of ''Oxygonum'', ''Pteroxygonum'', and ''Rumex'', and a new circumscription of ''Koenigia'' |journal=Taxon |volume=64 |issue=6 |pages=1188–1208 |doi=10.12705/646.5 |name-list-style=amp}}</ref>
{{Polygoneae cladogram}}

==Species==

Between 65<ref name="fna">{{cite web | url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=126398 | title = Polygonum | work = Flora of North America}}</ref> and 300 species have been recognised at various times, depending on the circumscription of the genus. A number of species that had been included in ''Polygonum'' have been moved into several other genera, including ''[[Bistorta]]'', ''[[Fagopyrum]]'', ''[[Fallopia]]'', ''[[Koenigia]]'', ''[[Persicaria]]'' and ''[[Reynoutria]]''. Other genera, such as ''Polygonella'', have been subsumed into ''Polygonum''.

{{As of|2019|February}}, [[Plants of the World Online]] accepted 129 species.<ref name=POWO_Polygonum>{{cite web |title=''Polygonum'': accepted species |work=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:331872-2 |access-date=2019-02-28}}</ref>
{{Div col|colwidth=25em}}
*''[[Polygonum acerosum]]'' <small>Ledeb. ex Meisn.</small>
*''[[Polygonum acetosum]]'' <small>M.Bieb.</small>
*''[[Polygonum achoreum]]'' <small>S.F.Blake</small>
*''[[Polygonum adenopodum]]'' <small>Sam.</small>
*''[[Polygonum afromontanum]]'' <small>Greenway</small>
*''[[Polygonum agreste]]'' <small>Sumnev.</small>
*''[[Polygonum ajanense]]'' <small>(Regel & Tiling) Grig.</small>
*''[[Polygonum albanicum]]'' <small>Jáv.</small>
*''[[Polygonum americanum]]'' <small>(Fisch. & C.A.Mey.) T.M.Schust. & Reveal</small>
*''[[Polygonum amgense]]'' <small>Michaleva & Perfiljeva</small>
*''[[Polygonum arenarium]]'' <small>Waldst. & Kit.</small>
*''[[Polygonum arenastrum]]'' <small>Boreau</small>
*''[[Polygonum argyrocoleon]]'' <small>Steud. ex Kunze</small>
*''[[Polygonum articulatum]]'' <small>L.</small>
*''[[Polygonum austiniae]]'' <small>Greene</small>
*''[[Polygonum aviculare]]'' <small>L.</small>
*''[[Polygonum balansae]]'' <small>Boiss.</small>
*''[[Polygonum basiramia]]'' <small>(Small) [[Tanja Schuster|T.M.Schust.]] & Reveal</small>
*''[[Polygonum bellardii]]'' <small>All.</small>
*''[[Polygonum biaristatum]]'' <small>Aitch. & Hemsl.</small>
*''[[Polygonum bidwelliae]]'' <small>S.Watson</small>
*''[[Polygonum bolanderi]]'' <small>W.H.Brewer ex A.Gray</small>
*''[[Polygonum boreale]]'' <small>(Lange) Small</small>
*''[[Polygonum bornmuelleri]]'' <small>Litv.</small>
*''[[Polygonum bowenkampii]]'' <small>Phil.</small>
*''[[Polygonum brasiliense]]'' <small>K.Koch</small>
*''[[Polygonum californicum]]'' <small>Meisn.</small>
*''[[Polygonum cascadense]]'' <small>W.H.Baker</small>
*''[[Polygonum caspicum]]'' <small>Kom.</small>
*''[[Polygonum ciliinode]]'' <small>Michx.</small> – fringed black bindweed, mountain bindweed
*''[[Polygonum cognatum]]'' <small>Meisn.</small>
*''[[Polygonum corrigioloides]]'' <small>Jaub. & Spach</small>
*''[[Polygonum deciduum]]'' <small>Boiss. & Noë</small>
*''[[Polygonum delopyrum]]'' <small>T.M.Schust. & Reveal</small>
*''[[Polygonum dentoceras]]'' <small>T.M.Schust. & Reveal</small>
*''[[Polygonum douglasii]]'' <small>Greene</small>
*''[[Polygonum effusum]]'' <small>Meisn.</small>
*''[[Polygonum engelmannii]]'' <small>Greene</small>
*''[[Polygonum equisetiforme]]'' <small>Sm.</small>
*''[[Polygonum erectum]]'' <small>L.</small>
*''[[Polygonum exsertum]]'' <small>Small</small>
*''[[Polygonum fibrilliferum]]'' <small>Kom.</small>
*''[[Polygonum fimbriatum]]'' <small>Elliott</small>
*''[[Polygonum floribundum]]'' <small>Schltdl. ex Spreng.</small>
*''[[Polygonum fowleri]]'' <small>B.L.Rob.</small>
*''[[Polygonum fragile]]'' <small>Sumnev.</small>
*''[[Polygonum glaucum]]'' <small>Nutt.</small>
*''[[Polygonum gussonei]]'' <small>Tod.</small>
*''[[Polygonum heterophyllum]]'' <small>Sol. ex Meisn.</small>
*''[[Polygonum heterosepalum]]'' <small>M.Peck & Ownbey</small>
*''[[Polygonum hickmanii]]'' <small>H.R.Hinds & Rand.Morgan</small>
*''[[Polygonum huananense]]'' <small>A.J.Li</small>
*''[[Polygonum humifusum]]'' <small>C.Merck ex K.Koch</small>
*''[[Polygonum icaricum]]'' <small>Rech.f.</small>
*''[[Polygonum idaeum]]'' <small>Hayek</small>
*''[[Polygonum imberbe]]'' <small>Sol. ex G.Forst.</small>
*''[[Polygonum inflexum]]'' <small>Kom.</small>
*''[[Polygonum istanbulicum]]'' <small>M.Keskin</small>
*''[[Polygonum jaxarticum]]'' <small>Sumnev.</small>
*''[[Polygonum korotkovae]]'' <small>Sumnev.</small>
*''[[Polygonum kudriaschevii]]'' <small>Vassilkovsk.</small>
*''[[Polygonum lacerum]]'' <small>Kunth</small>
*''[[Polygonum liaotungense]]'' <small>Kitag.</small>
*''[[Polygonum longiocreatum]]'' <small>Bartlett</small>
*''[[Polygonum longipes]]'' <small>Halácsy & Charrel</small>
*''[[Polygonum majus]]'' <small>(Meisn.) Piper</small>
*''[[Polygonum marinense]]'' <small>T.R.Mert. & P.H.Raven</small>
*''[[Polygonum maritimum]]'' <small>L.</small>
*''[[Polygonum mezianum]]'' <small>H.Gross</small>
*''[[Polygonum minimum]]'' <small>S.Watson</small>
*''[[Polygonum molliiforme]]'' <small>Boiss.</small>
*''[[Polygonum myrtillifolium]]'' <small>Kom.</small>
*''[[Polygonum nesomii]]'' <small>T.M.Schust. & Reveal</small>
*''[[Polygonum nuttallii]]'' <small>Small</small>
*''[[Polygonum oxanum]]'' <small>Kom.</small>
*''[[Polygonum oxyspermum]]'' <small>C.A.Mey. & Bunge</small>
*''[[Polygonum palastinum]]'' <small>Zohary</small>
*''[[Polygonum papillosum]]'' <small>Hartvig</small>
*''[[Polygonum parksii]]'' <small>(Cory) T.M.Schust. & Reveal</small>
*''[[Polygonum paronychia]]'' <small>Cham. & Schltdl.</small>
*''[[Polygonum paronychioides]]'' <small>C.A.Mey.</small>
*''[[Polygonum parryi]]'' <small>Greene</small>
*''[[Polygonum patulum]]'' <small>M.Bieb.</small>
*''[[Polygonum peruvianum]]'' <small>Meisn.</small>
*''[[Polygonum pinicola]]'' <small>T.M.Schust. & Reveal</small>
*''[[Polygonum plebeium]]'' <small>R.Br.</small>
*''[[Polygonum polycnemoides]]'' <small>Jaub. & Spach</small>
*''[[Polygonum polygaloides]]'' <small>Meisn.</small>
*''[[Polygonum polygamum]]'' <small>Vent.</small>
*''[[Polygonum polyneuron]]'' <small>Franch. & Sav.</small>
*''[[Polygonum pringlei]]'' <small>Small</small>
*''[[Polygonum pulvinatum]]'' <small>Kom.</small>
*''[[Polygonum ramosissimum]]'' <small>Michx.</small>
*''[[Polygonum rectum]]'' <small>(Chrtek) H.Scholz</small>
*''[[Polygonum recumbens]]'' <small>Royle ex Bab.</small>
*''[[Polygonum rigidum]]'' <small>Skvortsov</small>
*''[[Polygonum romanum]]'' <small>Jacq.</small>
*''[[Polygonum rottboellioides]]'' <small>Jaub. & Spach</small>
*''[[Polygonum rupestre]]'' <small>Kar. & Kir.</small>
*''[[Polygonum rurivagum]]'' <small>Jord. ex Boreau</small>
*''[[Polygonum sabulosum]]'' <small>Vorosch.</small>
*''[[Polygonum salsugineum]]'' <small>M.Bieb.</small>
*''[[Polygonum sanguinaria]]'' <small>Remy</small>
*''[[Polygonum sawatchense]]'' <small>Small</small>
*''[[Polygonum schistosum]]'' <small>Czukav.</small>
*''[[Polygonum scoparium]]'' <small>Req. ex Loisel.</small>
*''[[Polygonum sericeum]]'' <small>Pall.</small>
*''[[Polygonum serpyllaceum]]'' <small>Jaub. & Spach</small>
*''[[Polygonum shastense]]'' <small>W.H.Brewer ex A.Gray</small>
*''[[Polygonum simlense]]'' <small>Royle ex Bab.</small>
*''[[Polygonum smallianum]]'' <small>T.M.Schust. & Reveal</small>
*''[[Polygonum spergulariiforme]]'' <small>Meisn. ex Small</small>
*''[[Polygonum striatulum]]'' <small>B.L.Rob.</small>
*''[[Polygonum stypticum]]'' <small>Cham. & Schltdl.</small>
*''[[Polygonum subaphyllum]]'' <small>Sumnev.</small>
*''[[Polygonum tenoreanum]]'' <small>E.Nardi & Raffaelli</small>
*''[[Polygonum tenue]]'' <small>Michx.</small>
*''[[Polygonum tenuissimum]]'' <small>A.I.Baranov & Skvortsov ex Vorosch.</small>
*''[[Polygonum thymifolium]]'' <small>Jaub. & Spach</small>
*''[[Polygonum tiflisiense]]'' <small>Kom.</small>
*''[[Polygonum tubulosum]]'' <small>Boiss.</small>
*''[[Polygonum turgidum]]'' <small>Thuill.</small>
*''[[Polygonum turkestanicum]]'' <small>Sumnev.</small>
*''[[Polygonum undulatum]]'' <small>(L.) P.J.Bergius</small>
*''[[Polygonum utahense]]'' <small>Brenckle & Cottam</small>
*''[[Polygonum valerii]]'' <small>A.K.Skvortsov</small>
*''[[Polygonum volchovense]]'' <small>Tzvelev</small>
*''[[Polygonum vvedenskyi]]'' <small>Sumnev.</small>
*''[[Polygonum zaravschanicum]]'' <small>Zakirov</small>
{{Div col end}}

===Reclassified species===

Many species formerly placed in ''Polygonum'' have been moved to other genera in the subfamily [[Polygonoideae]]. Some synonyms are listed below.<ref name=POWO_PolygonumSpp>{{cite web |title=Search for ''Polygonum'' species |work=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|url=https://powo.science.kew.org/results?q=Polygonum&f=species_f |access-date=2019-02-28}}</ref>

====''Polygonum'' species that have been reclassified as ''Bistorta''====
*''Polygonum amplexicaule'' → ''[[Bistorta amplexicaulis]]''
*''Polygonum bistorta'' – bistort → ''[[Bistorta officinalis]]''
*''Polygonum bistortoides'' <small>Pursh</small> – American bistort, western bistort, smokeweed or mountain meadow knotweed → ''[[Bistorta bistortoides]]''
*''Polygonum tenuicaule'' <small>Bisset & S.Moore</small> → ''[[Bistorta tenuicaulis]]''
*''Polygonum viviparum'' – alpine bistort → ''[[Bistorta vivipara]]''

====''Polygonum'' species that have been reclassified as ''Fagopyrum''====
*''Polygonum fagopyrum'' <small>L.</small> – buckwheat → ''[[buckwheat|Fagopyrum esculentum]]''

====''Polygonum'' species that have been reclassified as ''Fallopia''====
*''Polygonum aubertii'' <small>L.Henry</small> → ''[[Fallopia aubertii]]''
*''Polygonum baldschuanicum'' <small>Regel</small> – Russian vine → ''[[Fallopia baldschuanica]]''
*''Polygonum convolvulus'' <small>L.</small> – black bindweed, wild buckwheat → ''[[Fallopia convolvulus]]''
*''Polygonum dumetorum'' <small>L.</small> → ''[[Fallopia dumetorum]]''
*''Polygonum scandens'' <small>L.</small> → ''[[Fallopia scandens]]''

====''Polygonum'' species that have been reclassified as ''Koenigia''====
*''Polygonum alpinum'' → ''[[Koenigia alpina]]''
*''Polygonum campanulatum'' – lesser knotweed, bellflower smartweed → ''[[Koenigia campanulata]]''
*''Polygonum davisiae'' <small>W.H. Brewer ex A. Gray</small> and ''Polygonum newberryi'' <small>Small</small> → ''[[Koenigia davisiae]]''
*''Polygonum molle'' → ''[[Koenigia mollis]]''
*''Polygonum polystachyum'' <small>Wall. ex Meisn.</small> → ''[[Koenigia polystachya]]''

====''Polygonum'' species that have been reclassified as ''Persicaria''====

*''Polygonum alatum'' → ''[[Persicaria nepalensis]]''
*''Polygonum amphibium'' – amphibious bistort, longroot smartweed, water smartweed → ''[[Persicaria amphibia]]''
*''Polygonum capitatum'' – pinkhead smartweed → ''[[Persicaria capitata]]''
*''Polygonum chinense'' <small>L.</small> → ''[[Persicaria chinensis]]''
*''Polygonum coccineum'' <small>Muhl. ex Willd.</small> → ''[[Persicaria amphibia]]''
*''Polygonum filiforme'' <small>Thunb.</small> → ''[[Persicaria filiformis]]''
*''Polygonum hydropiper'' – water-pepper → ''[[Persicaria hydropiper]]''
*''Polygonum hydropiperoides'' <small>Michx.</small> – swamp smartweed → ''[[Persicaria hydropiperoides]]''
*''Polygonum lapathifolium'' – pale persicaria or nodding smartweed → ''[[Persicaria lapathifolia]]''
*''Polygonum longisetum'' → ''[[Persicaria longiseta]]''
*''Polygonum minus'' – small water-pepper → ''[[Persicaria minor]]''
*''Polygonum mite'' <small>Schrank</small> – tasteless water-pepper → ''[[Persicaria mitis]]'' <small>(Schrank) Assenov</small>
*''Polygonum nepalense'' → ''[[Persicaria nepalensis]]''
*''Polygonum odoratum'' <small>Lour.</small> – Vietnamese coriander → ''[[Persicaria odorata]]''
*''Polygonum orientale'' → ''[[Persicaria orientalis]]''
*''Polygonum pensylvanicum'' – Pennsylvania smartweed or pink knotweed or pinkweed → ''[[Persicaria pensylvanica]]''
*''Polygonum perfoliata'' – Asiatic Tearthumb → ''[[Persicaria perfoliata]]''
*''Polygonum persicaria'' – redshank or persicaria or lady's thumb → ''[[Persicaria maculosa]]''
*''Polygonum praetermissum'' → ''[[Persicaria praetermissa]]''
*''Polygonum punctatum'' <small>Elliott</small> – dotted smartweed → ''[[Persicaria punctata]]''
*''Polygonum runcinatum'' → ''[[Persicaria runcinata]]''
*''Polygonum sagittatum'' – arrowleaf tearthumb, American tear-thumb or scratchgrass → ''[[Persicaria sagittata]]''
*''Polygonum tinctorium'' → ''[[Persicaria tinctoria]]''
*''Polygonum virginianum'' <small>L.</small> → ''[[Persicaria virginiana]]''

====''Polygonum'' species that have been reclassified as ''Reynoutria''====
*''Polygonum multiflorum'' <small>Thunb.</small> → ''[[Reynoutria multiflora]]''
*''Polygonum cuspidatum'' <small>Siebold & Zucc.</small> – Japanese knotweed → ''[[Reynoutria japonica]]''
*''Polygonum sachalinense'' <small>F.Schmidt</small> – giant knotweed → ''[[Reynoutria sachalinensis]]''

===Unresolved species===

*''Polygonum vaccinifolium'' <small>Wall.</small> is an unresolved species name. ''[[Persicaria vaccinifolia]]'' may be a synonym.

== Uses ==

Several species can be eaten cooked,<ref>[http://www.northernbushcraft.com/plants/knotweed/notes.htm Knotweed at NorthernBushCraft]</ref> for example during famines.<ref>{{cite journal | journal = J Ethnobiol Ethnomed | year = 2008 | volume = 4 | doi = 10.1186/1746-4269-4-4 |pmc=2275233 | title = Archival data on wild food plants used in Poland in 1948 | author = Łukasz Łuczaj | pages = 4| pmid = 18218132 | issue=1 | doi-access = free }}</ref> The species ''[[Polygonum cognatum]]'', known locally as "madimak",<ref>See the preparation of one particular dish in Turkey using ''Polygonum cognatum'': https://www.youtube.com/watch?v=DzNCO94rWXE</ref><ref>One more dish based on "madimak" polygonum cognatum: https://www.youtube.com/watch?v=p3cJk6ChPkY</ref> is regularly consumed in central parts of Turkey.

==References in literature==
In ''[[The Man Who Laughs]]'' Victor Hugo wrote of the [[Comprachicos]] (child-buyers) who created artificial dwarfs, formed "by anointing babies' spines with the grease of bats, moles and dormice" and using drugs such as "dwarf elder, knotgrass, and daisy juice". The idea of such use was also known to [[Shakespeare]], as Beatrice K. Otto pointed out, quoting ''[[A Midsummer Night's Dream]]'':<ref>{{cite book
|last= Otto
|first= Beatrice K.
|title= Fools are Everywhere: The Court Jester Around the World
|chapter-url= https://books.google.com/books?id=KSTK1C7LqegC&q=Comprachicos&pg=PA29
|access-date= 2008-04-28
|publisher= [[University of Chicago Press]]
|isbn= 0-226-64091-4
|chapter= Facets of the Fool
|page= 29
|year= 2001
|orig-year= 2001-04-01 
}}</ref>

{{Poem quote|Get you gone, dwarf;
You minimus, of hindering knot-grass made;}}

==References==
{{Reflist|refs=
<!--<ref name=PlantList>{{cite web| title=The Plant List: ''Polygonum'' |date=2013 |url=http://www.theplantlist.org/tpl1.1/search?q=polygonum |publisher=Royal Botanic Gardens, Kew and Missouri Botanic Garden}}</ref>-->
}}

==External links==
{{Commons category}}
*[http://internt.nhm.ac.uk/jdsml/nature-online/nature-navigator/ Natural History Museum, London: Nature-navigator website]
*[https://www.rhs.org.uk/plants/search-form Royal Horticultural Society: Plant Finder section website]
*[http://www.habitas.org.uk/flora/index.html Flora of Northern Ireland]

{{Taxonbar|from=Q271400}}
{{Authority control}}

[[Category:Polygonum| ]]
[[Category:Polygonaceae genera]]
[[Category:Botanical taxa named by Carl Linnaeus]]