Which of the following is not a single flower ?

Options

A. China rose
B. Petunia
C. Sunflower
D. Periwinkle

Answer

To determine which of the following options is not a single flower, we need to analyze each option based on the concept of inflorescence and flower morphology.

### Step-by-Step Solution:

1. **Understanding Flower Structure**:
- A flower is the reproductive structure of angiosperms (flowering plants).
- Flowers can be solitary (single) or part of an inflorescence (a cluster of flowers).

2. **Analyzing the Options**:
- **Option A: China Rose (Hibiscus rosa-sinensis)**:
- Belongs to the Malvaceae family.
- It produces solitary flowers, meaning each flower is individual and not part of a cluster.
- **Option B: Petunia**:
- An ornamental plant from the Solanaceae family.
- Petunias also produce solitary flowers, similar to the periwinkle.
- **Option C: Sunflower (Helianthus annuus)**:
- A member of the Asteraceae family, also known as the sunflower family.
- Sunflowers do not produce a single flower; instead, they have a flower head composed of many small flowers (ray florets) grouped together.

3. **Conclusion**:
- After analyzing the options, it is clear that both China Rose and Petunia produce solitary flowers, while Sunflower is characterized by its flower head, which contains multiple small flowers.
- Therefore, the correct answer is **Option C: Sunflower**, as it is not a single flower but an inflorescence.

### Final Answer:
**C. Sunflower**