The various appendages (sepals, petals, stamens and carpels) in the flower ofAntirrhinum are initiated in a centripetal sequence. The five sepal primordia are initiated in a rapid succession as discrete units. The calyx tube is formed due to the fusion of marginal meristems of adjacent sepal primordia. The corolla tube is also initiated by the fusion of marginal meristems at the back of stamen primordia. In the later stage of development, it extends in length by zonal growth. Of the five stamen primordia formed, the posterior one develops into a staminode. The septum, which bears placentae, grows from the summit of the floral apex as in typical axile placentation.