Classification of aquatic plants

1. Floating plants:

• Are free-floating with their leaves above the water surface, and their roots are within water but not attached to the soil.
• Eh: Eichhornia (water hyacinth), Pistia (Water lettuce), Spirodela (Giant duckweed), Lemna (duckweed), Azolla (Water fern), Salvinia (Water fern), etc.

2. Emergent plants:

• Are rooted in the bottom soil but have all or some of their leaves and flowers above the water surface.
• Prefer shallow parts and shores of the pond.
• Eg: Nymphaea (Water lilies), Nelumbo (Lotus), Trapa (Water chestnut), Nymphoids (Floating heart), etc.

3. Submerged plants:

• Are completely submerged in water and may or may not be rooted.
• E.g.: Rooted submerged weeds: Vallisneria, Najas, Hydrilla, etc., and without roots: Ceratophyllum and Utricularia.

4. Marginal Plants:

• Grow on the margins or the shore line of the water body.
• Are mostly rooted in water-logged soils.
• Eg: Typha, Ipomoea, Panicum, Colocasia, etc.

5. Filamentous algae:

• Forms ‘algal mats’ in and around the main water body.
• The most prominent filamentous algae in ponds are Spirogyra and Pithophora.

6. Planktonic algae:

• Results in algal bloom.
• Impart different colors to the water like green, yellowish brown, reddish brown, bluish green, etc.
• Eh: Microcystis, Anabaena, Oscillatoria, Volvox, Chlorella, Euglena, etc.