Which one is found only in aquatic plant

Options

A. Runner
B. Stolon
C. Tuber
D. Offset

Answer

To determine which structure is found only in aquatic plants, we will analyze the options provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding the Options**:
- We have four options: runners, stolons, tubers, and offsets. We need to identify which of these is specifically associated with aquatic plants.

2. **Analyzing Runners**:
- Runners are elongated, prostrate branches that grow along the ground. They are commonly found in terrestrial plants, particularly grasses. Since they are not exclusive to aquatic plants, we can eliminate this option.

3. **Analyzing Stolons**:
- Stolons are similar to runners but are typically above ground. They also serve as a means of vegetative reproduction. Like runners, stolons are not exclusive to aquatic plants and are found in various terrestrial plants. Thus, we can eliminate this option as well.

4. **Analyzing Tubers**:
- Tubers are a type of stem modification that serves as a storage organ. A well-known example is the potato. Tubers are primarily found in terrestrial plants and are not specific to aquatic plants. Therefore, we can eliminate this option too.

5. **Analyzing Offsets**:
- Offsets are short horizontal branches that produce clusters of leaves above and roots below. They are specifically associated with some aquatic plants. For example, offsets are found in water hyacinth (Eichhornia) and pistia. This makes offsets the correct answer as they are found only in aquatic plants.

### Conclusion:
The correct answer is **offsets**, as they are specifically found in aquatic plants.

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