Certain non-leguminous plants also form nodules to fix `N_(2)`. Example of such plants is

Options

A. Alnus
B. Casuarina
C. Myrica
D. all of these

Answer

### Step-by-Step Solution:

1. **Understanding Nitrogen Fixation**: Nitrogen fixation is the process through which atmospheric nitrogen (N₂) is converted into a form that plants can use, such as ammonia. This is crucial for plant growth as nitrogen is a vital nutrient.

2. **Role of Nodules**: In many plants, especially legumes, nitrogen fixation occurs in specialized structures called nodules. These nodules house symbiotic bacteria that convert atmospheric nitrogen into usable forms for the plant.

3. **Identifying Non-Leguminous Plants**: While legumes are well-known for forming nodules, certain non-leguminous plants also possess this ability.

4. **Examples of Non-Leguminous Plants**:
- **Alnus** (Alder) is a well-known non-leguminous plant that forms nodules with the help of the actinobacteria, Frankia.
- **Casuarina** is another example where nodules are formed for nitrogen fixation.
- **Myrica** (also known as Bayberry) is included in this category as well.

5. **Conclusion**: Therefore, the non-leguminous plants that form nodules to fix nitrogen include Alnus, Casuarina, and Myrica. The correct answer to the question is that these plants are examples of non-leguminous plants that can fix nitrogen through nodule formation.

### Final Answer:
Certain non-leguminous plants that form nodules to fix nitrogen include **Alnus, Casuarina, and Myrica**.

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