Flower is actinomorphic in Petunia.

Explanation

**Step-by-Step Solution:**

1. **Understanding Actinomorphism**: Actinomorphic flowers are those that exhibit radial symmetry. This means that if you were to cut the flower through its center in any direction, the two halves would be mirror images of each other.

2. **Identifying Petunia**: The flower of Petunia is known for its symmetrical structure. When we observe a Petunia flower, we can see that it has a regular shape that allows for this symmetry.

3. **Visualizing the Flower**: To confirm that Petunia is actinomorphic, visualize or draw the flower. If you can draw lines through the center of the flower in multiple directions and each section looks the same, it confirms the actinomorphic nature.

...