Hydrophily

Hydrophily is a mode of pollination wherein pollen is distributed by the flow of waters, particularly in aquatic or water-loving plants. This method of pollination is primarily observed in aquatic plants (hydrophytes) and in some terrestrial species. Hydrophily is a relatively rare method of pollination, as most plants are pollinated by insects (entomophily) or wind (anemophily).

Types of Hydrophily

Hydrophily can be classified into two types: Epihydrophily and Hypohydrophily.

Epihydrophily is a type of pollination that occurs on the water surface. This is observed in some species of waterweeds and pondweeds (Potamogeton). In this type, the pollen floats on the water surface and reaches the stigma of the flower.

Hypohydrophily occurs below the water surface. This is observed in sea grasses like Zostera and Ceratophyllum. In this type, the pollen grains are heavier than water and sink down to reach the stigma of the flower.

Mechanism of Hydrophily

In hydrophilous species, the flowers are small and inconspicuous. They produce a large amount of pollen to increase the chances of successful pollination. The pollen grains of hydrophilous plants are long and ribbon-like, which helps them to float on the water surface. The pollen grains are also protected by a mucilaginous covering that prevents them from getting wet.

The flowers of hydrophilous plants are often unisexual, which promotes outcrossing. The male flowers release their pollen onto the water surface, which is then carried by water currents to the female flowers.

Examples of Hydrophilous Plants

Some examples of hydrophilous plants include the water eelgrass (Vallisneria) and the tape grass (Zostera).

See Also

• Pollination
• Anemophily
• Entomophily
• Zoophily