Abstract: The floral development of Kmeria septentrionalis Dandy(Magnoliaceae) is reported for the first time using scanning electron microscope. The so-called linear-lanceolate inner tepals in pistillate flowers are actually staminodes whose initial time and ontogenetic positions are the same as those of the stamens in staminate flowers. In addition, a few vestigial anther cells, remained in some matured staminodes, indicate that the pistillate flower of K. septentrionalis is evolved from the bisexual flower. The pistillate floral morphology of K. septentrionalis is found similar to those of K. duperreana(Pierre) Dandy and Magnolia thailandica Noot. & Chalermglin, therefore, the structures between tepals and pistils are staminodes in pistillate flowers of the three species.

Key words: Kmeria septentrionalis Dandy, Magnoliaceae, inner tepal, staminode, organogenesis