Name the nitrogen-fixing bacteria present in root nodules of leguminous plants.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of nitrogen-fixing bacteria that are found in the root nodules of leguminous plants.

2. **Identifying Leguminous Plants**: Leguminous plants are a group of plants that belong to the family Fabaceae. They are known for their ability to form symbiotic relationships with certain bacteria.

3. **Recognizing Nitrogen-Fixing Bacteria**: Nitrogen-fixing bacteria are microorganisms that can convert atmospheric nitrogen into a form that plants can use for growth.

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