Leaves which do not bear distinction between upper and lower surface are called________ leaves

Explanation

**Step-by-Step Solution:**

1. **Understanding Leaf Structure**:
- Leaves can have different structures based on their anatomy. Typically, leaves have an upper (adaxial) and lower (abaxial) surface, which can be distinguished by their texture, color, and function.

2. **Identifying the Type of Leaf**:
- In some leaves, there is no clear distinction between the upper and lower surfaces. This means that the mesophyll tissue, which is the inner tissue of the leaf, does not differentiate into distinct layers.

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