Which of the following flowers produce assured seed set even in the absence of pollinators ?

Options

A. Viola , Commelina - Xenogamous flowers
B. Viola , Oxalis - Cleistogamous flowers
C. Tomato , chilli - Cleistogamous flowers
D. Capsella , Brassica - Cleistogamous flowers

Answer

To solve the question, "Which of the following flowers produce assured seed set even in the absence of pollinators?" we need to analyze the options provided and understand the concepts of self-pollination and clistogamous flowers.

### Step-by-Step Solution:

1. **Understand Pollination Types**:
- **Self-Pollination**: This occurs when pollen from the same flower fertilizes its own ovules. It does not require external pollinators.
- **Cross-Pollination (Xenogamy)**: This involves pollen from one flower fertilizing the ovules of another flower, which requires pollinators.

2. **Identify Clistogamous Flowers**:
- Clistogamous flowers are a type of flower that remains closed and does not open. In these flowers, the anthers and stigma are in close proximity, allowing self-pollination to occur without the need for pollinators.

3. **Analyze the Options**:
- **Option A**: Viola, Commelina, Xenogamous flower
- **Option B**: Viola, Oxalis, Clistogamous flower
- **Option C**: Tomato, Chili, Clistogamous flower
- **Option D**: Capsula, Brassica, Clistogamous flower

4. **Determine Which Options Contain Clistogamous Flowers**:
- From the options, we know that **Viola** and **Oxalis** are known to produce clistogamous flowers. Therefore, they can produce assured seed sets even in the absence of pollinators.

5. **Select the Correct Answer**:
- Since Option B includes both **Viola** and **Oxalis**, which are clistogamous flowers, the correct answer is **B**.

### Final Answer:
**B. Viola, Oxalis, Clistogamous flower**