Which of the following is not a water pollinated flower?

Yucca flower.

The correct answer is Option (2) - Yucca flower.

Water-pollinated flowers are those that rely on water to transport pollen from one flower to another. They are typically found in aquatic environments, such as lakes, rivers, and ponds.

Hydrilla, Vallisneria, and Zostera are all water-pollinated flowers.

Yucca flowers are not water-pollinated. They are terrestrial flowers that are pollinated by insects. Yucca flowers are primarily pollinated by specialized yucca moths, which act as the pollinators for these plants. The moths visit the yucca flowers to lay their eggs and, in the process, transfer pollen from one flower to another. Their flowers are not submerged underwater, and their pollen is not released into the water. Instead, these are carried to other flowers by insects.