Name the phenomenon of two flowers, one having long stamens and short styles, and other having short stamens and long style

Options

A. Allogamous device
B. Heterostyly
C. Dicliny
D. Herkogamy.

Answer

To solve the question regarding the phenomenon of two flowers with varying lengths of stamens and styles, follow these steps:

### Step-by-Step Solution:

1. **Understand the Components**: Identify the key components of the flowers mentioned in the question: one flower has long stamens and short styles, while the other has short stamens and long styles.

2. **Identify the Phenomenon**: Recognize that the difference in the lengths of stamens and styles serves a specific purpose, which is to prevent self-pollination.

3. **Define the Term**: The phenomenon where flowers exhibit different lengths of stamens and styles is known as "heterostyly." This is a reproductive strategy that promotes cross-pollination by ensuring that pollen from one flower does not easily fertilize its own ovules.

4. **Eliminate Other Options**: Consider the other terms provided in the question:
- Allogamous device: This term does not specifically refer to the length of stamens and styles.
- Decliny: This refers to the presence of unisexual flowers, which is not relevant here.
- Hercogamy: This involves barriers to self-pollination but does not specifically describe the variation in lengths of stamens and styles.

5. **Conclude the Answer**: Based on the understanding and elimination of other options, conclude that the correct answer is "heterostyly."

### Final Answer:
The phenomenon is called **heterostyly**.