Read  the given statements:

I- Plants species have a mucilaginous covering on their pollen grains.

II- This type of pollination is rare in flowering plants and is primarily observed in about 30 genera, mostly monocotyledons.

III- Examples of plants include Vallisneria, Hydrilla.

IV- In some species pollen grains are often long and ribbon-like.

The above features are the characteristics of :

Hydrophily (pollination by water )

• Water pollination is rare in flowering plants and is primarily observed in about 30 genera, mostly monocotyledons.
• Lower plant groups such as algae, bryophytes, and pteridophytes rely on water for the transport of male gametes.
• Some bryophytes and pteridophytes have limited distribution due to their dependence on water for male gamete transport and fertilization.
• Examples of water-pollinated plants include Vallisneria, Hydrilla, and marine sea-grasses like Zostera.
• Not all aquatic plants use water for pollination; many, such as water hyacinth and water lily, are pollinated by insects or wind.
• In Vallisneria, female flowers emerge above the water surface, while male flowers release pollen grains onto the water's surface to be carried passively by water currents.
• In seagrasses, female flowers remain submerged, and pollen grains are released into the water. These pollen grains are often long and ribbon-like, and they are carried passively by water until they reach the stigma for pollination.
• Water-pollinated species often have a mucilaginous covering on their pollen grains to protect them from wetting.