What type of water-pollinated plants have ribbon-like pollen grains?

Step-by-step solution

Pollination by water is quite rare in flowering plants and is limited to about 30 genera, mostly monocotyledons. In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind as in most of the land plants. In Vallisneria, the female flower reach 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 some of them eventually reach