Which one is not a pteridophyte

Options

A. Selaginella
B. Equisetum
C. Salvinia
D. Polytrichum.

Answer

To determine which option is not a pteridophyte, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Understand the Definition of Pteridophytes**:
- Pteridophytes are vascular plants that reproduce via spores and do not produce seeds. They include ferns, horsetails, and clubmosses.

2. **Analyze the Options**:
- **Option 1: Selaginella**
- Selaginella is a genus of plants in the class Lycopsida, which is a group of pteridophytes.
- **Conclusion**: Selaginella is a pteridophyte.

- **Option 2: Equisetum**
- Equisetum, commonly known as horsetails, belongs to the class Sphenopsida, which is also a group of pteridophytes.
- **Conclusion**: Equisetum is a pteridophyte.

- **Option 3: Salvinia**
- Salvinia is a genus of aquatic ferns that belong to the class Pteropsida, making it a pteridophyte as well.
- **Conclusion**: Salvinia is a pteridophyte.

- **Option 4: Polytrichum**
- Polytrichum is a genus of mosses and belongs to the group Bryophytes, which are non-vascular plants.
- **Conclusion**: Polytrichum is not a pteridophyte.

3. **Final Answer**:
- The option that is not a pteridophyte is **Polytrichum**.