Polygonum maritimum

Tracheophyta MagnoliopsidaPolygonaceaePolygonumPolygonum maritimum


A prostrate perennial herb of sand, shingle or shell beaches, growing above the limit of the highest tides with other strand-line and foredune plants. Lowland.



World Distribution

Mediterranean-Atlantic element.

© K.J. Walker, BSBI

Broad Habitats

Supralittoral sediment (strandlines, shingle, coastal dunes)

Light (Ellenberg): 9

Moisture (Ellenberg): 3

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 4

Salt Tolerance (Ellenberg): 3

January Mean Temperature (Celsius): 6

July Mean Temperature (Celsius): 16.2

Annual Precipitation (mm): 950

Height (cm): 20

Perennation - primary


Life Form - primary


Comment on Life Form

The books all say that it is a perennial



Clonality - primary

Little or no vegetative spread

Count of 10km squares in Great Britain: 16

Count of 10km squares in Ireland: 1

Count of 10km squares in the Channel Isles: 4

Atlas Change Index: 0.21

Plantatt Conservation Status


JNCC Designations


Atlas text references

Atlas (173d)
de Bolòs O, Vigo J
1990.  Flora dels Països Catalans, II. Crucíferes-Amarantàcies.
Curtis TGF, McGough HN
1988.  The Irish Red Data Book. 1. Vascular Plants.
Ferguson IK, Ferguson LF
1974.  Polygonum maritimum L. new to Ireland. Irish Naturalists’ Journal. 18:95.
Harmes PA, Spiers A
1993.  Polygonum maritimum L. in East Sussex (v.c. 14). Watsonia. 19:271-273.
Jalas & Suominen (1979)
Lousley JE, Kent DH
1981.  Docks and knotweeds of the British Isles. Botanical Society of the British Isles Handbook no. 3.
Wigginton MJ
1999.  British Red Data Books. 1. Vascular plants, edn 3.