This document discusses hydrophytes, which are plants that live fully or partially submerged in fresh water. It describes five categories of hydrophytes based on their relationship to water and air: free floating plants that float on the water surface and are not rooted; rooted floating plants with roots in the mud and leaves floating; submerged floating plants completely submerged with no contact with air or soil; rooted submerged plants completely submerged and rooted in soil; and amphibious plants adapted to both aquatic and terrestrial environments. Examples are given for each category. The document also summarizes anatomical adaptations of hydrophytes, such as thin leaves and stems, aerenchyma tissue for gas exchange, and poorly developed roots.