Often found in profusion over the surface of a slow-moving stream, pond or even a persistent ditch puddle, this is an aquatic plant found mainly in the East and Southwest of Scotland, and at some sites in the West, on the Western Isles and Orkney.
Stems are underwater or low growing, with sparse hairs, mainly on the stipules and leaf stalks. Leaves grow in a spiral up the stem and are of two types. The underwater leaves are deeply divided and feathery with hair-like segments, about 3 – 6cm in length. The leaf-stalks are often shorter than the leaf blades.
The second leaf-type floats on top of the water and is nearly circular in shape with 3-7 deeply cut, wedge-shaped toothed lobes, not unlike those of other Buttercups. Leaf stalks are longer than the blade, the extra length being required for the leaf to reach the surface.
Flowers are up to 18mm in diameter, with 5 rounded white petals, each with a splash of yellow at the base. Usually one flower grows opposite the upper leaf on its own long stalk which stands erect above the water’s surface. 5 short pointed sepals curl downwards beneath the petals. 13 or more yellow stamens stand upright in the middle of the corolla, and the gynoecium is made of numerous ovaries each with its own stigma. These grow into a cluster of nut-like fruits which are egg-shaped and hairy and don’t open, but drop to the bottom of the pond to begin breaking down so germination of the seed inside can take place.