`alpha` cellulose fibrous thickening is present in/on

Options

A. epidermis
B. tapeturn
C. outer tangential wall of endothecium
D. ineer tangential wall of endothecium

Answer

### Step-by-Step Solution:

1. **Understanding the Structure of Anther**: The anther is a crucial part of the male reproductive system in flowering plants, where pollen grains are formed. It consists of several layers, including the epidermis, endothecium, and tapetum.

2. **Identifying the Layers**:
- **Epidermis**: This is the outermost layer that provides protection.
- **Tapetum**: This is the innermost layer that supplies nutrients to the developing pollen grains.
- **Endothecium**: This layer is located between the epidermis and the tapetum.

3. **Focusing on Endothecium**: The endothecium is characterized by elongated cells that develop fibrous thickening. This thickening is primarily composed of alpha cellulose, which is a type of carbohydrate.

4. **Determining the Location of Alpha Cellulose**: The fibrous thickening made up of alpha cellulose is specifically found in the **inner tangent wall of the endothecium**. It is important to note that while the endothecium has an outer tangent wall, the alpha cellulose thickening is present in the inner tangent wall.

5. **Conclusion**: Therefore, the correct answer to the question is that alpha cellulose fibrous thickening is present in/on the **inner tangent wall of the endothecium**.