A vesselless piceof stem possessing prominent sieve tubes would belong to

Options

A. Pinus
B. Eucalyptus
C. Grass
D. Trochodendron

Explanation

To solve the question "A vesselless piece of stem possessing prominent sieve tubes would belong to," we need to analyze the options provided and understand the characteristics of the plants mentioned.

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Vesselless**: This indicates that the plant does not have vessels in its xylem. Vessels are typically found in angiosperms (flowering plants).
- **Prominent Sieve Tubes**: Sieve tubes are part of the phloem and are responsible for the transport of nutrients. The presence of prominent sieve tubes suggests that the plant has a well-developed phloem system.

2. **Analyzing the Options**:
- **Option 1: Pinus**:
- Pinus is a gymnosperm. Gymnosperms do not have vessels; however, they also lack sieve tubes. Therefore, this option cannot be correct as it does not have prominent sieve tubes.

- **Option 2: Eucalyptus**:
- Eucalyptus is an angiosperm and has vessels in its xylem. Since the question specifies a vesselless stem, this option is incorrect.

- **Option 3: Grass**:
- Grass is also an angiosperm and contains vessels. Therefore, it does not fit the criteria of being vesselless.

- **Option 4: Trochodendron**:
- Trochodendron is an angiosperm that is unique because it lacks vessels in its xylem but possesses prominent sieve tubes in its phloem. This makes it a suitable candidate for the question.

3. **Conclusion**:
- The correct answer is **Option 4: Trochodendron**. This plant is characterized by being vesselless while having prominent sieve tubes.

### Final Answer:
**Trochodendron**.