What are bicollateral vascular bundles?

Explanation

### Step-by-Step Solution:

1. **Definition of Bicollateral Vascular Bundles**: Bicollateral vascular bundles are a specific type of vascular arrangement found in certain plants, particularly in the Cucurbitaceae family (like cucumbers and pumpkins).

2. **Structure of Bicollateral Vascular Bundles**: In these bundles, the arrangement consists of one central strand of xylem surrounded by two strands of phloem.

3. **Position of Xylem and Phloem**: The xylem is located in the center of the vascular bundle, while the phloem is positioned on both the outer and inner sides of the xylem. This means that there are two phloem strands, one on each side of the xylem.

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