Medium to tall robust, stoloniferous, hairless plant with erect hollow, scarcely branched stems. Flowers large, bright glossy yellow 3 to 5 cm across. The leaves are variable, with the basal leaves being long stalked and withering early, whilst the stem leaves are short stalked or stalkless, long lanceolate and entire, being narrower at the base.
Marshy ground, fens, pond and stream margins. Often grows in shallow water.
Found at Rodley nature Reserve.