Synonyms for Menyanthes Trifoliata (same or very similar meaning)
WordNet sense 1 (perennial plant of Europe and America having racemes of white or purplish flowers and intensely bitter trifoliate leaves; often rooting at water margin and spreading across the surface):
bogbean, buckbean, water shamrock, bog myrtle, marsh trefoilFrom the ODE community, based on WordNetadd/edit