Pollination in Aquatic Flowering Plants
Aquatic flowering plants represent just about 2% of all flowering plants known. Yet they have not ceased to fascinate biologists with their perplexing assemblage of growth habits, unusual pollination mechanisms, widespread asexual propagation and polymorphism. The greatest diversity of aquatic angiosperms is found in fresh water environments. Aquatic flowering plants have pollination systems ranging from those independent of the aquatic environment, such as wind and animals, to varying degrees of adaptation to the aquatic environment, beginning with pollination at the surface of water to under water pollination with pollen adhering to the surface of air bubbles, to a totally aquatic mode in which the pollen sink in the water. Over 90% of all aquatic angiosperms bear aerial flowers and have the same manner of pollination as their terrestrial ancestors. True hydrophily is exhibited in a very few angiosperms and currently two classes of hydrophily are recognized: Ephydrophily- pollination at the surface of water i.e. in two dimensions and Hyphydrophily- pollination below the surface of water i.e. in three dimensions.