Fibrous thickenings of hygroscopic nature are found in which part of anther walls?

Options

A. epidermis
B. Tapetum
C. Middle layer
D. Endothecium.

Answer

To solve the question regarding the fibrous thickenings of hygroscopic nature found in the anther walls, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Anther Walls**:
- The anther is part of the stamen in flowering plants and consists of several layers. The main layers include the epidermis, the middle layer, and the innermost layer known as the endothecium.

**Hint**: Familiarize yourself with the anatomy of the anther and its layers.

2. **Identifying the Endothecium**:
- The endothecium is a layer of cells located just inside the epidermis of the anther. It is characterized by elongated cells that play a crucial role in the dehiscence of the anther, which is the process of releasing pollen.

**Hint**: Remember the position of the endothecium relative to other layers in the anther.

3. **Understanding Hygroscopic Nature**:
- Hygroscopic materials are those that can absorb moisture from the environment. In the context of the endothecium, the cells have fibrous thickenings that allow them to absorb water, which aids in the opening of the anther when it is time for pollen release.

**Hint**: Think about how moisture absorption can affect the function of the anther.

4. **Conclusion**:
- Based on the characteristics discussed, the fibrous thickenings of hygroscopic nature are specifically found in the endothecium of the anther walls.

**Hint**: Recall that the endothecium is the only layer mentioned that has hygroscopic properties due to its fibrous thickenings.

### Final Answer:
The fibrous thickenings of hygroscopic nature are found in the **endothecium** of the anther walls.