In dicotyledonous stem, endodermis is also referred to as the starch sheath, because -

Options

A. Its cells are rich in protein granules.
B. Its cells are rich in starch grains.
C. Its cells are rich in tannins
D. Its cells are rich in oil droplets

Answer

### Step-by-Step Solution:

1. **Understanding the Endodermis**:
- The endodermis is the innermost layer of the cortex in a dicotyledonous stem. It plays a crucial role in regulating the movement of water and nutrients into the vascular system.

2. **Structure of the Endodermis**:
- The cells of the endodermis are compactly arranged and are typically barrel-shaped. This compact arrangement helps in minimizing the spaces between the cells, which is important for its function.

3. **Absence of Intercellular Spaces**:
- In the endodermis, there are no intercellular spaces. This means that the cells are tightly packed together, which aids in forming a barrier that controls the flow of substances.

4. **Starch Sheath**:
- The term "starch sheath" comes from the fact that the endodermis often contains a rich deposition of starch grains within its cells. This starch storage is significant for the plant's energy needs.

5. **Conclusion**:
- Therefore, the endodermis is referred to as the "starch sheath" because of its compact barrel-shaped cells that are rich in starch grains, which are essential for the plant's metabolic processes.

### Final Answer:
In dicotyledonous stems, the endodermis is referred to as the starch sheath due to its barrel-shaped cells that are compactly arranged and rich in starch grains, which serve as a storage form of energy.

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