• Source: Polygonum

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 (c. 1400–1425), it was known as ars-smerte. 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 plants to erect herbaceous perennial plants.
Polygonum species are occasionally eaten by humans, and are used as food plants by the larvae 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 or perennial herbaceous plants, rarely shrubby, with much branched stems. The leaves are arranged alternately, usually less than 2 cm (0.8 in) long, with a length greater than the width. They have a membranous ochrea (a sheath around the stem nodes). The flowers are usually bisexual, rarely unisexual, and have five (occasionally four) tepals, the outer being slightly different from the inner ones. There are usually four to six stamens and three (rarely two) styles. The fruit is three-sided.




Taxonomy


The genus Polygonum was first described by Carl Linnaeus in 1754. The genus name is usually said to be from the Greek πολυ- (poly-, 'many') and γόνυ (gonu, 'knee' or 'joint'), in reference to the swollen jointed stem. 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 γόνος (gonos, 'offspring', 'seed'), the meaning of the name then being the Latin foecundus, i.e. 'fecund', 'with many offspring'. The Flora of North America says that a derivation meaning 'many seeds' is the "grammatically correct interpretation".
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, and older sources frequently use much wider definitions of the genus. Molecular phylogenetic studies, particularly in the 21st century, have led to major changes. Clarifying the circumscription of genera split from Polygonum was described in 2015 as "still ongoing".




= 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 and Atraphaxis, forming the so-called "DAP clade".




Species


Between 65 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 February 2019, Plants of the World Online accepted 129 species.




= Reclassified species

=
Many species formerly placed in Polygonum have been moved to other genera in the subfamily Polygonoideae. Some synonyms are listed below.



Polygonum species that have been reclassified as Bistorta

Polygonum amplexicaule → Bistorta amplexicaulis
Polygonum bistorta – bistort → Bistorta officinalis
Polygonum bistortoides Pursh – American bistort, western bistort, smokeweed or mountain meadow knotweed → Bistorta bistortoides
Polygonum tenuicaule Bisset & S.Moore → Bistorta tenuicaulis
Polygonum viviparum – alpine bistort → Bistorta vivipara



Polygonum species that have been reclassified as Fagopyrum

Polygonum fagopyrum L. – buckwheat → Fagopyrum esculentum



Polygonum species that have been reclassified as Fallopia

Polygonum aubertii L.Henry → Fallopia aubertii
Polygonum baldschuanicum Regel – Russian vine → Fallopia baldschuanica
Polygonum convolvulus L. – black bindweed, wild buckwheat → Fallopia convolvulus
Polygonum dumetorum L. → Fallopia dumetorum
Polygonum scandens L. → Fallopia scandens



Polygonum species that have been reclassified as Koenigia

Polygonum alpinum → Koenigia alpina
Polygonum campanulatum – lesser knotweed, bellflower smartweed → Koenigia campanulata
Polygonum davisiae W.H. Brewer ex A. Gray and Polygonum newberryi Small → Koenigia davisiae
Polygonum molle → Koenigia mollis
Polygonum polystachyum Wall. ex Meisn. → 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 L. → Persicaria chinensis
Polygonum coccineum Muhl. ex Willd. → Persicaria amphibia
Polygonum filiforme Thunb. → Persicaria filiformis
Polygonum hydropiper – water-pepper → Persicaria hydropiper
Polygonum hydropiperoides Michx. – 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 Schrank – tasteless water-pepper → Persicaria mitis (Schrank) Assenov
Polygonum nepalense → Persicaria nepalensis
Polygonum odoratum Lour. – 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 Elliott – 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 L. → Persicaria virginiana



Polygonum species that have been reclassified as Reynoutria

Polygonum multiflorum Thunb. → Reynoutria multiflora
Polygonum cuspidatum Siebold & Zucc. – Japanese knotweed → Reynoutria japonica
Polygonum sachalinense F.Schmidt – giant knotweed → Reynoutria sachalinensis




= Unresolved species

=
Polygonum vaccinifolium Wall. is an unresolved species name. Persicaria vaccinifolia may be a synonym.




Uses


Several species can be eaten cooked, for example during famines. The species Polygonum cognatum, known locally as "madimak", 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:




References






External links



Natural History Museum, London: Nature-navigator website
Royal Horticultural Society: Plant Finder section website
Flora of Northern Ireland

Kata Kunci Pencarian:

• Thorecta polygonum
• Keludah
• Sujak
• Resveratrol
• Si tuba sawah
• Polygonaceae
• Poligon
• William Miller
• Carl Meissner
• Taman Nasional Deosai
• Polygonum
• Persicaria maculosa
• Polygonum aviculare
• Reynoutria japonica
• Buckwheat
• Reynoutria multiflora
• Bistorta amplexicaulis
• Persicaria lapathifolia
• Persicaria tinctoria
• Polygonum cascadense