Information on Equal-leaved Knotgrass

Common Name: Equal-leaved Knotgrass
Scientific Name: Polygonum arenastrum
Irish Name: Glúineach ghainimh
Family Group: Polygonaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period


Click for list of all flowering by month
Equal-leaved Knotgrass could sometimes be confused with:

Knotgrass, Knotgrass, Ray's,

Always prostrate, this sprawling, mat-forming plant creeps on bare, sandy, coastal ground and on pathways, tracks and shingle. An annual, it is hairless, somewhat greyish and in some respects, very similar to Knotgrass/Polygonum aviculare. Its short, oval leaves are a good pointer to differentiation between the two species with all the leaves on the main and side stems being equal in size. From June to October, tiny flowers (2–3 mm) emerge from the leaf axils, petals very pale pink-edged with green interiors. This is a native plant belonging to the Polygonaceae family.

I first recorded and photographed this plant in 2010 while on a field-trip with BSBI Vice-County Recorder, Paul Green who kindly identified it.

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Knotgrass, Equal-leaved
Knotgrass, Equal-leaved