Photographs: Sherkin Island, Co. Cork

Ray's Knotgrass Polygonum oxyspermum (previously subsp. raii) Glúineach ghlé Family: Polygonaceae Flowering June-November. Annual, biennial or short-lived perennial Clusters of tiny greenish-white flowers with 5 petals, red-edged. The fruit is a glossy brown nut and longer than the calyx. Prostrate growth habit, the elliptical green-grey leaves with slightly rolled back edges. The sprawling stems often become woody at the base. Scattered distribution around the Irish coast on sand and shingle beaches, usually above the highest tide level.

Ray's Knotgrass, Polygonum oxyspermum (previously subsp. raii), Glúineach ghlé