Phyllotaxy is decussate in

Options

A. Nerium indicum
B. Pisum sativum
C. Hibiscus rosa-sinensis
D. Catharanthus roseus.

Answer

### Step-by-Step Solution:

1. **Understanding Phyllotaxy**:
- Phyllotaxy refers to the specific arrangement of leaves on a stem or branch. It is crucial to identify the type of phyllotaxy to answer the question correctly.

2. **Types of Phyllotaxy**:
- There are three basic types of phyllotaxy:
- **Alternate**: One leaf per node.
- **Opposite**: Two leaves per node.
- **Whorled**: More than two leaves per node.

3. **Focusing on Opposite Phyllotaxy**:
- Under opposite phyllotaxy, there are further classifications, namely:
- **Decussate**: Successive pairs of leaves are arranged at right angles to each other.
- **Superposed**: Leaves are stacked directly above one another.

4. **Analyzing the Options**:
- The options provided are:
- A) Nerea Mendicum
- B) Pisum Sativum
- C) Hibiscus Rosa Sinensis
- D) Catharanthus Roseus

5. **Evaluating Each Option**:
- **Nerea Mendicum**: This plant exhibits alternate phyllotaxy. (Incorrect)
- **Pisum Sativum**: This plant also has alternate phyllotaxy. (Incorrect)
- **Hibiscus Rosa Sinensis**: This plant shows alternate phyllotaxy as well. (Incorrect)
- **Catharanthus Roseus**: This plant has decussate phyllotaxy, where pairs of leaves are arranged perpendicularly to each other. (Correct)

6. **Conclusion**:
- The correct answer to the question "Phyllotaxy is decussate in" is **Catharanthus Roseus**.