A flower is defined as modified shoot wherein the shoot apical meristem changes to floral meristem.

A flower is defined as a modified shoot, and during the process of floral development, the shoot apical meristem undergoes a change to become a floral meristem. The shoot apical meristem is the growing tip of the stem, and when it transitions to a floral meristem, it starts producing floral organs, such as sepals, petals, stamens, and carpels, instead of leaves or vegetative structures.