The flowers of all these plants show assured seed- set even in the absence of pollinators, except in

Options

A. Sunflower
B. Common pansy
C. Oxalis
D. Commelina

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which plant's flowers do not guarantee seed set in the absence of pollinators. We need to identify the exception among the given options.

2. **Identifying the Options**: The options provided are:
- Sunflower
- Common Pansy
- Oxalis
- Comelina

3. **Defining Key Terms**:
- **Clistogamous Flowers**: These are flowers that do not open and have both male and female reproductive parts close together, allowing self-pollination (autogamy) to occur without the need for pollinators.
- **Homogamy**: This is a condition where a plant has only one type of flower that contains both male and female parts, but it may require pollinators for fertilization.

4. **Analyzing Each Option**:
- **Sunflower**: This plant exhibits homogamy and relies on pollinators for seed set. Therefore, it does not guarantee seed set in their absence.
- **Common Pansy**: This is a clistogamous flower, meaning it can self-pollinate without pollinators.
- **Oxalis**: Similar to the Common Pansy, Oxalis also has clistogamous flowers and can self-pollinate.
- **Comelina**: This plant also has clistogamous flowers, allowing it to set seeds without pollinators.

5. **Conclusion**: Based on the analysis, the sunflower is the only plant among the options that does not show assured seed set in the absence of pollinators. Therefore, the answer to the question is **Sunflower**.

### Final Answer:
The flowers of all these plants show assured seed set even in the absence of pollinators, except in **Sunflower**.

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