A small rootless aquatic herb in which a portion of leaf foms a tiny sach or bladder which traps water insects is

Options

A. Dionaea
B. Utricularia
C. Sarracenia
D. Drosera.

Explanation

To solve the question regarding the small rootless aquatic herb that forms a tiny sack or bladder to trap water insects, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics**: The question specifies a "small rootless aquatic herb" that has a portion of its leaf forming a "tiny sack or bladder." This indicates that we are looking for a plant that lives in water and has a unique structure for trapping insects.

2. **Review the Options**: The options provided are:
- Dynia (Venus flytrap)
- Utricularia (Bladderwort)
- Sarcenia (Pitcher plant)
- Drosera (Sundew)

3. **Analyze Each Option**:
- **Dynia (Venus Flytrap)**: This plant is known for its jaw-like structure that traps insects but is not aquatic and has roots.
- **Utricularia (Bladderwort)**: This is a rootless aquatic herb known for its bladder-like structures that trap small aquatic insects.
- **Sarcenia (Pitcher Plant)**: This plant has a pitcher-shaped structure to trap insects but is not typically aquatic and has roots.
- **Drosera (Sundew)**: This plant has sticky glandular hairs to trap insects but is not aquatic and has roots.

4. **Select the Correct Answer**: Based on the analysis, Utricularia (Bladderwort) is the only option that fits all the criteria: it is a small, rootless aquatic herb that forms bladders to trap insects.

5. **Conclusion**: Therefore, the answer to the question is **Utricularia**.