Polygonum oxyspermum explained

Polygonum oxyspermum is a coastal species of flowering plant in the buckwheat family. It is native to Europe, primarily along the shores of the Atlantic, the North Sea, and the Baltic Sea, from France and Ireland to Finland and Russia.^[1] It is also naturalized in eastern Canada and in the US State of Maine.^[2]

Description

Polygonum oxyspermum is green or blue-green. Annual, stems prostrate, generally run along the surface of the ground but sometimes do rise above ground level. They can be as much as 100cm (00inches) long. Leaves are up to 35mm long. Flowers are green, white or pink, in axillary clusters.^[3]

SubspeciesThree subspecies are widely recognized, although some authors prefer to regard them as distinct species.

• Polygonum oxyspermum subsp. oxyspermum – northern Europe; naturalized in Nova Scotia
• Polygonum oxyspermum subsp. raii (Bab.) D.A.Webb & Chater northern Europe; naturalized in Nova Scotia, Prince Edward Island, New Brunswick, Québec, Maine, Newfoundland
• Polygonum oxyspermum subsp. robertii (Loisel.) Akeroyd & D.A.Webb – Italy^[4]

External links

• A Photo Flora, Polygonum oxyspermum – Ray's Knotgrass (Polygonaceae Images) photos
• Flora of Northern Ireland

Notes and References

1. http://www.brc.ac.uk/plantatlas/index.php?q=plant/polygonum-oxyspermum Online Atlas of the British and Irish flora, Polygonum oxyspermum (Ray`s Knotgrass)
2. http://wilde-planten.nl/zandvarkensgras.htm Wilde Planten in Nederland en België, Zandvarkensgras
3. Parnell, J. and Curtis, T. 2012. Webb's An Irish Flora. Cork University Press.
4. http://www.actaplantarum.org/floraitaliae/viewtopic.php?t=135 Acta Plantarum, Polygonum robertii Loisel. – Poligono di Robert