Polygonum oxyspermum

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.^[2] It is also naturalized in eastern Canada and in the US State of Maine.^[3][4]

Polygonum oxyspermum
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Polygonaceae
Genus:	Polygonum
Species:	P. oxyspermum
Binomial name
Polygonum oxyspermum C.A.Mey. & Bunge ex Ledeb. 1824
Synonyms[1]
Polygonum acadiense Fernald Herniaria lenticulata Huds., syn of subsp. raii Polygonum mesembricum Chrtek, syn of subsp. raii Polygonum raii Bab., syn of subsp. raii Polygonum robertii Loisel., syn of subsp. robertii

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 100 cm (39 in) long. Leaves are up to 35 mm (1.4 in) long. Flowers are green, white or pink,^[5] in axillary clusters.^[6]

Subspecies

Three subspecies are widely recognized, although some authors prefer to regard them as distinct species.^[1]

• Polygonum oxyspermum subsp. oxyspermum – northern Europe; naturalized in Nova Scotia^[7]
• Polygonum oxyspermum subsp. raii (Bab.) D.A.Webb & Chater northern Europe; naturalized in Nova Scotia, Prince Edward Island, New Brunswick, Québec, Maine, Newfoundland^[8]
• Polygonum oxyspermum subsp. robertii (Loisel.) Akeroyd & D.A.Webb – Italy^[9]