Marsh St. John's-wort
Terminal cymes of pale-yellow flowers with red dots on sepals. Upright flower stems. Oval-circular leaves, clasping stem. Usually woolly-hairy. Creeping plant, rooting at lower stem nodes, mat-forming. Height: 15-25 cm.
Damp or wet peaty, nutrient-poor soils. Usually in shallow water, sometimes terrestrial. Acidic marshes, bogs, streams. Most frequent in W and SW Ireland.