This document classifies and describes different types of hydrophytes:
1. Submerged hydrophytes that grow entirely below the water surface, including submerged floating plants like Ceratophyllum that are not rooted and rooted plants like Hydrilla.
2. Floating hydrophytes that float on or just below the water surface, including free-floating plants like Pistia and rooted plants like Nymphaea whose petioles are suspended in water.
3. Rooted emergent hydrophytes like Sgittaria and Marsilea that are adapted to both aquatic and terrestrial environments, with shoots growing above the water and roots fixed in muddy soil below.