This is not an example of aerial modification of stem

Options

A. Corm
B. Tendril
C. Thorn
D. Phylloclade

Answer

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for an option that is not an example of aerial modification of the stem.

2. **Identify the Options**: The options provided are:
- Comb
- Tendril
- Thorn
- Phylloclade

3. **Define Aerial Modifications of Stem**: Aerial modifications of the stem are adaptations that occur above ground and serve various functions such as support, defense, or photosynthesis.

4. **Analyze Each Option**:
- **Comb**: This is a swollen stem base that is typically underground and serves as a food storage organ. It does not function as an aerial modification.
- **Tendril**: This is a slender, coiling structure that helps plants climb and provides support. It is an aerial modification.
- **Thorn**: This is a sharp, pointed structure that provides defense against herbivores. It is also an aerial modification.
- **Phylloclade**: This is a flattened stem that performs photosynthesis and is an aerial modification.

5. **Conclusion**: Among the options, the comb is not an aerial modification of the stem; it is an underground structure. Therefore, the correct answer is **Comb**.

### Final Answer:
The option that is not an example of aerial modification of stem is **Comb**.

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