The mode of arrangement of sepals or petals in floral bud is known as :-

Options

A. Phyllotaxy
B. Aestivation
C. Placentation
D. Ptyxis

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the arrangement of sepals or petals in a floral bud.

2. **Analyzing the Options**: We have four options to consider:
- Phyllotaxy
- Estivation
- Placentation
- Taxis

3. **Evaluating Each Option**:
- **Phyllotaxy**: This term refers to the arrangement of leaves on the stem or axis of a plant. Since the question specifically asks about sepals or petals, this option is not relevant.
- **Estivation**: This term refers to the arrangement of sepals or petals in a floral bud before it opens. This is the correct definition we are looking for.
- **Placentation**: This term refers to the arrangement of ovules within the ovary of a flower. It does not relate to sepals or petals, so this option is incorrect.
- **Taxis**: This term refers to the arrangement of leaves in a bud, which again does not pertain to sepals or petals. Thus, this option is also incorrect.

4. **Conclusion**: After evaluating all the options, the correct answer is **Estivation**, as it specifically refers to the arrangement of sepals or petals in the floral bud.

**Final Answer**: The mode of arrangement of sepals or petals in a floral bud is known as **Estivation**.

---