water shamrock vs hydrophytic plant

As nouns, hydrophytic plant is a hypernym of water shamrock; that is, hydrophytic plant is a word with a broader meaning than water shamrock:

• water shamrock: 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
• hydrophytic plant: a plant that grows partly or wholly in water whether rooted in the mud, as a lotus, or floating without anchorage, as the water hyacinth