Erect tufted perennial herb suckering along stems to 2m. Erect or floating leaves, shiny green round or kidney-shaped 3-8cm long, paler or purplish below, base heart-shaped, basal leaves on stalks to 68cm long depending on water depth. Erect open branched yellow flowerhead at the end of long flower stalk. Open flowers 19-43mm wide with broad entire or scalloped lobes, styles the same length in all flowers.