Brown hair found at the base of Pteris leaves are
(a) Modified stipules
(b) Modified leaflets
(c) Ramenta
(d) Spines

Options

A. Modified stipules
B. Modified leaflets
C. Ramenta
D. Spines.

Answer

To solve the question regarding the brown hair found at the base of Pteris leaves, we will analyze each option provided and determine which one correctly identifies these structures.

### Step-by-Step Solution:

1. **Understanding the Question**:
The question asks about the brown hairs located at the base of Pteris leaves. Pteris is a genus of ferns, which are classified under pteridophytes.

2. **Analyzing Each Option**:
- **Option (a): Modified stipules**:
Stipules are small leaf-like structures at the base of a leaf stalk. They do not refer to the brown hairs found on Pteris leaves. Therefore, this option is incorrect.

- **Option (b): Modified leaflets**:
Leaflets are the individual segments of a compound leaf. The brown hairs are not modified leaflets. Thus, this option is also incorrect.

- **Option (c): Ramenta**:
Ramenta refers to the brown hairs or scales found at the base of fern leaves, specifically in younger leaves. This matches the description given in the question.

- **Option (d): Spines**:
Spines are sharp, pointed structures that are typically found on plants for protection. The brown hairs do not serve this purpose, making this option incorrect.

3. **Conclusion**:
After analyzing all the options, the correct answer is (c) Ramenta, as it accurately describes the brown hairs found at the base of Pteris leaves.

### Final Answer:
(c) Ramenta