Source : Webster's Revised Unabridged Dictionary (1913)

Hydrophyte \Hy"dro*phyte\, n. [Gr. ? + ? plant: cf. F.
   hydrophyte.]
   An aquatic plant; an alga.

Source : WordNet®

hydrophyte
     n : 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 [syn: {aquatic plant}, {water plant},
         {hydrophytic plant}]