In water hyacinth and water lily, pollination takes place by

In water hyacinth and water lily pollination is done by insects or wind although these are hydrophytes. Water is  used a medium for gamete transfer in algae, bryophytes and pteridophytes.  Pollination by water is quite rare in flowering plants and is limited to about 30 genera, mostly monocotyledons. Some examples of water pollinated plants are Vallisneria and Hydrilla which grow in fresh water and several marine sea-grasses such as Zostera. Pollination in gymnosperms takes place with the help of air currents.