Name the structure in leaflet of Cycas, which performs the function of lateral vein.

Explanation

**Step-by-Step Solution:**

1. **Identify the Leaflet Structure**: In Cycas, the leaflets are referred to as "pinnules." This is the first step in understanding the structure of the leaf.

2. **Understand the Vascular Arrangement**: Within the pinnules, there are vascular bundles. These bundles are crucial for the transport of nutrients and water within the leaf.

3. **Recognize the Function of Lateral Veins**: The lateral veins in a leaf typically help in the distribution of water and nutrients throughout the leaf structure. In Cycas, the vascular bundles arranged in a co-joint and collateral manner perform this function.

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