There are many kinds of flowers, but like other plants, whether from seed to germination, the life cycle of flowers changes as well as the annual cycle. The development of plants starts from the embryo, the underground part develops from the root tip, and the aboveground organs develop from the stem tip. Meristem is the main part of shoot tip, and it has different properties at different stages of individual development. The development of aboveground stems, leaves and flowers of plants is essentially the constant change of meristem characteristics of stem tips. At the same time, some meristems are transformed into various organ primordia, such as leaf bud primordia and flower bud primordia. One of the most important changes is the stage change from vegetative growth to reproductive growth; From the attribute of meristem, it is the transformation of meristem from vegetative to reproductive. Among them, the development of meristem finally stopped at the stage of flower organ primordium, and lost the ability to continuously form new secondary meristem and new organs, which is the decisive factor of flower bud.