Light energy is used by the flower to bloom that could allow the flower to remove its pollen for the pollination process. Also the light allows the flower or the plants to make food and that is why they bloom if its is portrayed be the light.
Explanation:
The greater the intensity of light, the more photons or photoelectrons there are and consequently the increase in photocurrent. Thus, the larger the energy, the greater the wattage of the light source.