In which of the following aestivation, sepal/ petal's one margin covers the other and its second margin is covered by previous one ?

Options

A. Valvate
B. imbricate
C. Twisted
D. Quincunical

Answer

To solve the question regarding the type of aestivation where one margin of a sepal or petal covers another, and its second margin is covered by the previous one, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Aestivation**: Aestivation refers to the arrangement of sepals or petals in a flower bud before it opens. It describes how these floral parts overlap or touch each other.

2. **Identify the Options**: The options given are:
- Valvet
- Imbricate
- Twisted
- Quincuncial

3. **Analyze Each Option**:
- **Valvet**: In this type, the margins of sepals or petals simply touch each other but do not overlap. Therefore, this option does not fit the description.
- **Imbricate**: In imbricate aestivation, one sepal or petal overlaps the margins of two adjoining members. However, it does not satisfy the condition where one margin covers the other while the second margin is covered by the previous one.
- **Twisted**: In twisted aestivation, each sepal or petal overlaps the next one in such a way that one margin covers the next, while the other margin is covered by the previous one. This matches the description given in the question.
- **Quincuncial**: In this arrangement, out of five members, two are outer, two are inner, and the fifth overlaps along its own margin. This does not meet the requirement of the question.

4. **Conclusion**: Based on the analysis, the correct answer is **Twisted Aestivation**. This type is commonly found in plants such as hibiscus and nerium.

### Final Answer:
**Twisted Aestivation**

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