Select the statement that is not correct.

Options

A. In aquatic plants like water hyacinth, pollination is carried out by insect or wind
B. In Vallisneria , the male flowers reach the surface of the water by a long stalk to liberate pollen grains.
C. In seagrasses , female flowers remain submerged in water.
D. Vallisneria and Hydrilla grow in freshwater while Zostera grows in seawater.

Answer

To solve the question of identifying the incorrect statement from the provided options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1**: "In aquatic plants like water hyacinth, pollination is carried out by the insect or wind."
- **Analysis**: This statement is correct. Water hyacinth is an aquatic plant that can be pollinated by insects (entomophily) and by wind (anemophily).

2. **Statement 2**: "In Valisneria, the male flowers reach the surface of the water by a long stalk to liberate pollen grains."
- **Analysis**: This statement is incorrect. In Valisneria, the male flowers do not reach the surface by a long stalk; instead, the male flowers release pollen grains into the water, which are then carried by water currents to the female flowers that are submerged.

3. **Statement 3**: "In seagrasses, female flowers remain submerged in water."
- **Analysis**: This statement is correct. In seagrasses, the female flowers are indeed submerged in water.

4. **Statement 4**: "Valisneria and Hydrilla grow in fresh water while Zostera grows in sea water."
- **Analysis**: This statement is also correct. Valisneria and Hydrilla are freshwater plants, while Zostera is a marine plant.

### Conclusion:
The statement that is not correct is **Statement 2**: "In Valisneria, the male flowers reach the surface of the water by a long stalk to liberate pollen grains."

### Final Answer:
**The incorrect statement is Statement 2.**

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