What is the Pollinating Agent for Water hyacinth and Water lily?

Aquatic plants are mostly pollinated by water (hydrophilly). For example, in vallisneria, Hydrilla and Zostera water is the source for pollinating flowers. Vallisneria is a dioecious plant meaning both male and female plants are separate.

The female flower reaches on the surface of water by the long stalk while the male flower remains under water. When both flowers mature, staminate flowers release pollen grains on the water surface and reach female flowers through water currents. After pollination and fertilization, the female stalk coils and pulls the fertilized flower below the water surface for further development. Hydrilla and Zostera have male and female flowers on different branches of the same plant. All the above mentioned plants come under submerged category.

However, in free floating aquatic plants such as Eicchornia (water hyacinth), and water lily (Nymphaea) – flowers are present above the water surface. In such plants, pollinating agents are either winds or insects.