Comment upon the mode of pollination in Vallisneria and Eichhornia which have emergent flowers.

Explanation

In Eichhornia the flowers emerge above the level of water and are pollinated by insects or wind. In Vallisneria, the female flower reches the surface of water by the long stalk and the male flowers or pollen grains are released on to the surface of water. They are carried passively by water current, some of them eventually reach the female flowers and the stigma.