This is a prostrate, native annual plant. It has 3mm, pinkish-white, 5-lobed flowers which are borne in clusters of 2-6 in leaf axils along ridged, sprawling stems. It can spread to 100cm long. The leaves are alternate, oval, leathery, grey-green with the margins slightly downturned. Nut-like fruits protrude beyond withering flowers, unlike Knotgrass or Equal-leaved Knotgrass. Its habitat is usually undisturbed, sandy beaches, shingle at extreme high-tide level. It belongs to the Dock family.
I first saw this plant at Lady's Island Lake in Co Wexford in 2012 when it was pointed out to me by the BSBI Vice-county Recorder for Wexford and Waterford, Paul Green.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre