Classed on the National Invasive Species Database as ‘Potentially Invasive’ this is a handsome, hairless, aquatic perennial which is a popular ornamental pond plant. It was introduced into Ireland in the 19th century and was subsequently found in several lakes and other water bodies, mainly in the northern half of the country. It favours still and slow-flowing water where it bears attractive yellow, 5-petalled flowers (3-4cm) in small clusters on stalks which rise from the surface of the water from June to September. The petals are fringed and slightly turned-in. In a similar manner to the flowers of Primroses, Cowslips and Bog-bean, some of these flowers may be ‘pin-eye’ and others ‘thrum-eye’ (see Primrose page for explanation). This is a bottom-rooted species which has meter-long stolons which lie below the surface of the water. The floating leaves are circular to heart-shaped, 3-10cm long. The fruit is a capsule which contains flat, oval seeds which have hairy edges. This plant belongs to the Nymphaceae or Waterlily family.
I first saw this plant in Co Mayo in 2014 when I photographed it. It was a long way off and I couldn’t get near enough to it to photograph it very clearly, having to use a long lens. I live in hope of finding it growing a little closer next time!
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre