Synonyms for Water Dragon (same or very similar meaning)
WordNet sense 1 (North American herbaceous perennial of wet places having slender curled racemes of small white flowers):
lizard's-tail, Saururus cernuus, swamp lilyWordNet sense 2 (swamp plant of Europe and North America having bright yellow flowers resembling buttercups):
cowslip, kingcup, marsh marigold, Caltha palustris, May blob, meadow brightFrom the ODE community, based on WordNetadd/edit