''Polygonum oxyspermum'' is a coastal species of flowering plant in the

buckwheat family The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus ''Polygonum'', and was first used by Antoine Laurent de Jussieu in 1789 ...

. 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. It is also naturalized in eastern Canada and in the US State of

Maine Maine () is a U.S. state, state in the New England and Northeastern United States, Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and territories of Canad ...

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 long. Leaves are up to long. Flowers are green, white or pink, in axillary clusters. ;Subspecies Three subspecies are widely recognized, although some authors prefer to regard them as distinct species. * ''Polygonum oxyspermum'' subsp. ''oxyspermum'' – northern Europe; naturalized in

Nova Scotia Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native En ...

* ''Polygonum oxyspermum'' subsp. ''raii'' (Bab.) D.A.Webb & Chater northern Europe; naturalized in

Prince Edward Island Prince Edward Island (PEI; ) is one of the thirteen provinces and territories of Canada. It is the smallest province in terms of land area and population, but the most densely populated. The island has several nicknames: "Garden of the Gulf", ...

New Brunswick New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen Provinces and territories of Canada, provinces and territories of Canada. It is one of the three Maritime Canada, Maritime provinces and one of the four Atlantic Canad ...

Québec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirteen p ...

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

* ''Polygonum oxyspermum'' subsp. ''robertii'' (Loisel.) Akeroyd & D.A.Webb –

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

Acta Plantarum, ''Polygonum robertii'' Loisel. – Poligono di Robert
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References

External links

photos * ttp://www.habitas.org.uk/flora/species.asp?item=3746 Flora of Northern Ireland oxyspermum Flora of Europe Plants described in 1824 {{Polygonaceae-stub