Idrofili

Idrofili, or hydrophily, is a pollination mechanism in which pollen is dispersed by water rather than by wind or animals. It is an adaptation found in a minority of flowering plants, typically aquatic or amphibious species, whose flowers or inflorescences encounter the water surface or submerged reproductive tissues.

There are two main forms: epihydrophily, where pollen grains are released at or near the water surface and reach stigmas at the surface; and hypohydrophily, where pollen is released underwater and must germinate and fertilize submerged stigmas.

Well-known examples include certain pondweeds (Potamogeton), Vallisneria, Hydrilla, and other submerged or emergent aquatic plants. Hydrophilous pollen is often large and may be mucilaginous to aid flotation or adhesion to stigmas.

Hydrophily is generally efficient only in stable, calm waters and tends to limit pollen dispersal range; it is relatively rare among flowering plants compared to entomophily (insect pollination) or anemophily (wind pollination). It can be affected by water turbidity, currents, and depth, which influence the contact between pollen and stigma.

Ecologically, hydrophily reduces reliance on animal pollinators and wind but ties reproduction to aquatic conditions. Some species exhibit mixed pollination strategies, combining aspects of aquatic pollen transfer with other pollen vectors to ensure reproductive success.