Vascular cambium of stem is

Options

A. partly primary and partly secondary meristem
B. primary meristem
C. secondary meristem
D. intercalary meristem

Answer

### Step-by-Step Solution:

1. **Understanding Vascular Cambium**:
- Vascular cambium is a layer of meristematic cells in plants. These cells are capable of division and contribute to the growth of the plant.

2. **Location of Vascular Cambium**:
- It is located between the xylem (inner layer) and phloem (outer layer) in the vascular system of the stem. This positioning is crucial for its function.

3. **Function of Vascular Cambium**:
- The primary function of vascular cambium is to produce new xylem and phloem cells. This process is essential for the transport of water, nutrients, and food throughout the plant.

4. **Types of Meristematic Tissues**:
- Meristematic tissues can be classified into primary and secondary types. Primary meristems are responsible for the initial growth of the plant, while secondary meristems contribute to the increase in thickness (secondary growth).

5. **Vascular Cambium Characteristics**:
- Initially, in young stems, vascular cambium appears in patches. As the plant matures and growth continues, these patches form a continuous ring around the stem, facilitating secondary growth.

6. **Conclusion**:
- Given that vascular cambium contributes to both primary and secondary growth, it is classified as "partly primary and partly secondary meristem."

7. **Final Answer**:
- Therefore, the correct answer to the question "Vascular cambium of stem is" is **Option A: partly primary and partly secondary meristem**.