Identify the correct name of marine plant, pollinated by water.

The correct answer is Option (4) → Zostera

In hydrophily, pollination is done by water. It is found in only about 30 genera, mostly monocots. Some water-pollinated plants live in fresh water and some in the sea, so the question is which of these is a marine plant.

(1) Vallisneria — Incorrect. It is water-pollinated, but it grows in fresh water.

(2) Hydrilla — Incorrect. It is water-pollinated, but it also grows in fresh water.

(3) Eichhornia — Incorrect. This is the water hyacinth. Its flowers rise above the water and are pollinated by insects or wind, not by water.

(4) Zostera — Correct. It is a marine sea-grass pollinated by water.

NCERT Extract:
Pollination – “… As against this, you would recall that water is a regular mode of transport for the male gametes among the lower plant groups such as algae, bryophytes and pteridophytes. It is believed, particularly for some bryophytes and pteridophytes, that their distribution is limited because of the need for water for the transport compact inflorecence and wellexposed stamens of male gametes and fertilisation. Some examples of water pollinated plants are Vallisneria and Hydrilla which grow in fresh water and several marine sea-grasses such as Zostera.”