Photographs: Inchigeela, Co. Cork

Water-cress Nasturtium officinale (Rorippa nasturtium-aquaticum) Biolar Family: Brassicaceae Flowering time: June-September. Perennial. Native. Small, white, 4-petalled flowers followed by cylindrical fruit with a double row of seeds. Pinnate dark-green leaves with oval leaflets remain green through winter. Creeping, branched stems, rooting in mud. When growing in polluted water or areas with sheep it may be infected with liver fluke. Can be common in shallow streams, ditches and other muddy places but rare in central Ireland. Similar: Narrow-fruited Water-cress. Fruit with single row of seeds

Water-cress, Nasturtium officinale, Biolar