Very much a plant of damp, boggy places and ditches through July and August, this is somewhat similar to our Common Ragwort except it has far fewer flowers in its clusters, they are quite open clusters and each yellow flower is larger than Common Ragwort, being 2-3cm across. The petals are longer and they have wider spaces between them. The leaves also differ being more pinnatifid and having a larger end lobe. Formerly known as Senecio aquaticus, this is a native plant and belongs to the family Asteraceae.
I first identified this plant in Trooperstown, Co Wicklow in 1976 and photographed it by the River Caher in the Burren, Co Clare in 2009.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre