Which of the following is not a water pollination plant ?

Options

A. Zostera
B. Vallisneria
C. Hydrilla
D. Cannabis

Explanation

To determine which of the following plants is not a water pollination plant, we need to analyze the options provided: Zostera, Bellisneria, Hydrilla, and Cannabis.

### Step-by-Step Solution:

1. **Understand Water Pollination**: Water pollination, also known as hydrophily, involves the transfer of pollen through water. Plants that utilize this method typically have specific adaptations.

2. **Identify Characteristics of Water Pollinating Plants**:
- They usually have small flowers.
- Their flowers are often odorless.
- They do not produce nectar.
- Pollen grains are unwettable and often have a mucilage cover to aid in floating and drifting in water.

3. **Examine Each Option**:
- **Zostera**: This is a genus of seagrass that is known to be a water pollinator.
- **Bellisneria**: This is another aquatic plant that is adapted for water pollination.
- **Hydrilla**: This is a submerged aquatic plant that also relies on water for pollination.
- **Cannabis**: This plant is known for wind pollination (anemophily) rather than water pollination. It has small, odorless, and nectarless flowers, but it does not utilize water for pollen transfer.

4. **Conclusion**: Based on the characteristics and the methods of pollination, the plant that is not a water pollination plant is **Cannabis**.

### Final Answer:
The plant that is not a water pollination plant is **Cannabis** (Option D).

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