Unicostate venation is called as

Options

A. Palmate
B. Pinnate
C. Reticulate
D. Parallel.

Answer

**Step-by-Step Solution:**

1. **Understanding Venation**: First, we need to understand what venation is. Venation refers to the pattern of veins in a leaf. It is important to identify the types of venation to answer the question correctly.

2. **Types of Venation**: There are two primary types of venation:
- **Reticulate Venation**: This type involves an irregular distribution of veins that form a network-like pattern.
- **Parallel Venation**: In this type, the veins run parallel to each other without intersecting.

3. **Identifying Unicostate Venation**: The term "unicostate" refers to a leaf that has a single principal vein. This is also known as **pinnate venation**. In pinnate venation, there is one main vein (the midrib) from which lateral veins branch out.

4. **Distinguishing Other Types**:
- **Palmate Venation**: This type involves multiple principal veins originating from a single point, making it multicostate. Therefore, it does not fit the definition of unicostate.
- **Reticulate and Parallel**: Both of these options do not represent unicostate venation.

5. **Conclusion**: Based on the definitions and characteristics of the types of venation, the correct answer to the question "Unicostate venation is called as" is **pinnate**.

**Final Answer**: Pinnate

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