The mismatched pair among the following is :

Options

A. Monadephous - Hibiscus
B. Diadelphous - Cucurbita
C. Polyadelphous - Citrus
D. Variation in the length of stamen filaments - Salvia

Answer

To solve the question regarding the mismatched pair among the given plants (Hibiscus, Cucurbita, Citrus, and Salvia), we will analyze the floral morphology of each plant, particularly focusing on the structure of the androsium (male reproductive part).

### Step-by-Step Solution:

1. **Understanding Androsium Types**:
- The androsium is the male reproductive part of a flower, consisting of stamens. The arrangement of stamens can be classified into different types:
- **Monadelphous**: All stamens fused into a single group.
- **Diadelphous**: Stamens arranged in two distinct groups.
- **Polyadelphous**: Stamens arranged in more than two groups.

2. **Analyzing Each Plant**:
- **Hibiscus**:
- The stamens are fused together into a single tubular structure. Therefore, Hibiscus exhibits a **monadelphous** condition.
- **Cucurbita**:
- The stamens in Cucurbita are also fused into a single group, which means it also exhibits a **monadelphous** condition, not diadelphous.
- **Citrus**:
- In Citrus, the stamens are typically arranged in more than two groups, which corresponds to a **polyadelphous** condition.
- **Salvia**:
- Salvia exhibits variation in the length of its stamens, which can be of unequal lengths, but this does not affect the classification of the androsium type.

3. **Identifying the Mismatched Pair**:
- From the analysis:
- Hibiscus: Monadelphous (correct)
- Cucurbita: Monadelphous (incorrectly labeled as diadelphous)
- Citrus: Polyadelphous (correct)
- Salvia: Variation in filament length (correct)
- The mismatched pair is **Cucurbita**, which is incorrectly described as diadelphous.

### Conclusion:
The mismatched pair among the options is **Cucurbita**, as it does not exhibit a diadelphous condition but rather a monadelphous one.

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