The pollination in the Vallisneria is achieved with the help of water. In Vallisneria, the female flowers are submerged in the water. They reach the surface of water by the long stalk on reaching maturity. At this time, the male flowers are released onto the surface of water. With the help of the water, the pollens come in contact with the female flowers and the pollination is achieved.  In the case of water lily, the female flowers remain submerged in water. The pollen grains are released inside the water. The pollen grains are long, thread-like and are carried with the water and reach the stigma and achieve pollination.