Which of the following fern spreads very fast by means of leaf tip?

Options

A. Pteridium
B. Azolla
C. Adiantum
D. Alsophila

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which fern spreads rapidly through its leaf tip. We need to identify the correct fern from the given options.

2. **Analyzing the Options**: The options provided are:
- Eridum
- Azolla
- Adiantum
- Phyla

3. **Identifying Characteristics of Each Option**:
- **Eridum**: Not commonly known for rapid spread through leaf tips.
- **Azolla**: Known as mosquito fern, primarily reproduces through water and not leaf tips.
- **Adiantum**: Known as the walking fern, which is characterized by the ability to produce new plants from its leaf tips.
- **Phyla**: Known as tree fern, does not spread through leaf tips.

4. **Focusing on Adiantum**: The key characteristic of Adiantum (Adiantum caudatum) is that it has adventitious buds at the leaf tips. When these leaf tips touch the ground, they can develop into new plants, allowing for rapid spread.

5. **Conclusion**: Based on the analysis, the fern that spreads very fast by means of leaf tips is **Adiantum**.

### Final Answer:
The correct option is **Adiantum**.

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