Which one of the following is an example of cleistogamy?

Options

A. Sunflower
B. Vallisneria
C. Commelina
D. Calatropics

Answer

To determine which of the given options is an example of cleistogamy, we need to understand what cleistogamy is and identify the correct plant associated with it.

### Step-by-Step Solution:

1. **Understanding Pollination**:
- Pollination is the process where pollen grains (male gametes) are transferred from the anthers (male part of the flower) to the stigma (female part of the flower).

2. **Types of Pollination**:
- There are two main types of pollination:
- **Chasmogamy**: This involves flowers that open and allow for cross-pollination.
- **Cleistogamy**: This involves flowers that do not open at all, leading to self-pollination.

3. **Characteristics of Cleistogamous Flowers**:
- Cleistogamous flowers have their anthers and stigma close together, which facilitates self-pollination.
- These flowers do not open, hence there is no opportunity for cross-pollination.

4. **Identifying Examples of Cleistogamy**:
- Common examples of plants that exhibit cleistogamy include:
- **Viola** (Violets)
- **Oxalis** (Wood Sorrel)
- **Commelina** (Dayflower)

5. **Analyzing the Given Options**:
- The options provided are:
- Sunflower
- Wallisneria
- Cormelia
- Callotropis
- Among these, **Cormelia** is known to have cleistogamous flowers.

6. **Conclusion**:
- Therefore, the correct answer to the question "Which one of the following is an example of cleistogamy?" is **Cormelia**.

### Final Answer:
**Cormelia** is an example of cleistogamy.