Green stem with nodes and internodes occurs in

Options

A. Lycopodium
B. Selaginella
C. Equisetum
D. Pteridium

Answer

To solve the question "Green stem with nodes and internodes occurs in," we need to analyze the options provided and identify which plant has a green stem with nodes and internodes.

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Green Stem**: Refers to stems that are green in color, often due to the presence of chlorophyll, which is involved in photosynthesis.
- **Nodes and Internodes**: Nodes are points on the stem where leaves or branches arise, while internodes are the segments of the stem between two nodes.

2. **Analyze the Options**:
- **A. Lycopodium**: This is a genus of clubmosses. They typically have a more woody appearance and do not have a distinct green stem with nodes and internodes.
- **B. Selaginella**: This is a genus of spikemosses. While they do have some green parts, they do not exhibit the typical structure of nodes and internodes like higher vascular plants.
- **C. Equicetum**: This is a genus commonly known as horsetails. They have a distinct green stem that is jointed with clear nodes and internodes.
- **D. Pteridium**: This is a genus of ferns known as bracken. While they have stems, they do not have the same structure of nodes and internodes as seen in Equicetum.

3. **Identify the Correct Answer**:
- After analyzing all the options, it is clear that **Equicetum** (C) is the only option that has a green stem with distinct nodes and internodes.

4. **Conclusion**:
- Therefore, the correct answer to the question is **C. Equicetum**.