Polygonum

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(Redirected from Knotgrass)

iPolygonum

Polygonum maritimum, sea knotgrass

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Caryophyllales
Family:	Polygonaceae
Genus:	Polygonum L.

Species

Between 150-300 species; see text

Polygonum is a genus in the buckwheat family Polygonaceae. The name is probably derived from the Greek poly, "many" and gonu, "knot". There is another theory which states that the second part of the name is derived from Greek gonos, "children". Common names include knotweed, knotgrass, bistort and several others.

The genus primarily grows in northern temperate regions. They vary widely from prostrate herbaceous annual plants under 5 cm high, others erect herbaceous perennial plants growing to 3–4 m tall, and yet others perennial woody vines growing to 20–30 m high in trees; several are also aquatic, growing as floating plants in ponds. The smooth-edged leaves vary greatly in shape between species, and can be narrow lanceolate, oval, broad triangular, heart shaped or arrowhead shaped; they range from 1–30 cm long. The stems are often reddish or red-speckled. The flowers are small, pink, white, or greenish, forming in summer in dense clusters from the leaf joints or stem apices.

Polygonum species are used as food plants by the larvae of some Lepidoptera species - see list of Lepidoptera which feed on Polygonum.

1 Japanese Knotweed
2 Species
3 References/External links

[edit] Japanese Knotweed

Japanese Knotweed (Fallopia japonica, Polygonum cuspidatum) is a primary commercial source of Resveratrol supplements, marketed under a variety of names: Hu Zhang, Ko-jo-kon, He Shou Wu, Giant Knotweed, Fo-Ti and Polygonum.[1] It is replacing grape byproducts as a source, because it is more concentrated and cheaper.

Hu Zhang root extract is a traditional Chinese medicinal treatment.

Japanese Knotweed is considered an invasive pest in much of the US, UK, and elsewhere.

[edit] Species

Between 150–300 species are recognised depending on the circumscription of the genus; some botanists divide the genus up into several smaller genera, including Fagopyrum, Fallopia and Persicaria. Selected species include:

[edit] Reclassified as Fagopyrum

Polygonum fagopyrum (Fagopyrum esculentum) – buckwheat

[edit] Reclassified as Fallopia

Polygonum aubertii = Polygonum baldschuanicum
Polygonum baldschuanicum (Fallopia baldschuanica) (Fallopia aubertii, Bilderdykia aubertii, Bilderdykia balschuanicum) – Russian vine
Polygonum cilinode (Fallopia cilinodis, Bilderdykia cilinodis) – fringed black bindweed
Polygonum convolvulus (Fallopia convolvulus) – black bindweed, wild buckwheat
Polygonum cuspidatum = Polygonum japonicum - Japanese knotweed
Polygonum dumetorum (Fallopia dumetorum) – copse bindweed
Polygonum japonicum (Fallopia japonica, Reynoutria japonica) – Japanese knotweed
Polygonum multiflorum (Fallopia multiflora)
Polygonum sachalinense (Fallopia sachalinensis, Reynoutria sachalinensis) – giant knotweed
Polygonum scandens (Fallopia scandens)

[edit] Reclassified as Persicaria

Flowerhead of Persicaria maculata (syn. Polygonum persicara)

Polygonum affine (Persicaria affinis)
Polygonum alatum (Persicaria alata)
Polygonum alpinum – alpine knotweed (Persicaria alpina)
Polygonum amphibium – amphibious bistort (Persicaria amphibia)
Polygonum amplexicaule (Persicaria amplexicaulis)
Polygonum bistorta – bistort (Persicaria bistorta)
Polygonum campanulatum – lesser knotweed (Persicaria campanulata) (Reynoutria campanulatum)
Polygonum capitatum (Persicaria capitata)
Polygonum emodi (Persicaria emodi)
Polygonum filiforme (Persicaria virginiana)
Polygonum hydropiper – water-pepper (Persicaria hydropiper)
Polygonum lapathifolium – pale persicaria or nodding smartweed (Persicaria lapathifolia)
Polygonum longisetum (Persicaria longiseta)
Polygonum macrophyllum (Persicaria macrophylla)
Polygonum milletii (Persicaria milletii)
Polygonum minus – small water-pepper (Persicaria minor)
Polygonum mite – tasteless water-pepper (Persicaria mitis, Persicaria laxiflora)
Polygonum molle (Persicaria mollis)
Polygonum nepalense (Persicaria nepalensis)
Polygonum odoratum – Vietnamese coriander (Persicaria odorata)
Polygonum orientale (Persicaria orientalis)
Polygonum pensylvanicum – Pennsylania smartweed or pink knotweed or pinkweed (Persicaria pensylvanica)
Polygonum persicaria – redshank or persicaria or lady's thumb (Persicaria maculosa)
Polygonum polystachyum = Polygonum wallichii
Polygonum runciforme (Persicaria runcinata)
Polygonum sagittatum – arrowleaf tearthumb, American tear-thumb or scratchgrass (Persicaria sagittata)
Polygonum tenuicaule (Persicaria tenuicaulis)
Polygonum tinctorium (Persicaria tinctoria)
Polygonum vaccinifolium (Persicaria vaccinifolia)
Polygonum virginianum (Persicaria virginiana)
Polygonum viviparum – alpine bistort (Persicaria vivipara)
Polygonum wallichii – Himalayan knotweed (Persicaria wallichii)
Polygonum weyrichii (Persicaria weyrichii)