Circinate vernation in ferns refers to

Options

A. Presence of adventitious roots
B. Coiling of young leaves
C. Leaf gaps in stele
D. Attachment of sori on leaf surface

Answer

### Step-by-Step Solution:

1. **Understanding Circinate Vernation**:
- Circinate vernation is a specific type of leaf arrangement found in ferns (pteridophytes). The term "circinate" refers to the coiling or circular arrangement of young leaves.

2. **Identifying the Feature**:
- In ferns, the young leaves (often referred to as fiddleheads) are tightly coiled. This coiling is a characteristic feature of the early development of fern leaves.

3. **Purpose of Coiling**:
- The primary reason for this coiling is to protect the delicate tip of the young leaf as it develops. The coiled structure shields the growing tip from environmental factors and physical damage.

4. **Maturation Process**:
- As the leaf matures, the coiled structure gradually unfurls. The adaxial surface (the upper side of the leaf) becomes more prominent as the leaf opens up, revealing the full leaf structure.

5. **Conclusion**:
- Therefore, circinate vernation in ferns refers to the coiling of young leaves, which serves to protect the leaf tip during its early growth stages.

### Final Answer:
Circinate vernation in ferns refers to the coiling of young leaves to protect the tip during development.

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