Abstract: The initiation of the floral organs of Nandina domestica Thunb. (Berberidaceae) is of the trimemus-whorled pattern. Stamens and petals grew out from the lateral bifurcation of the common stamen-petal primordia; but petals underwent retarded periods of growth in their early development. Carpel initiation belongs to the ascidiate type. Some aspects concerning the trimerous floral organs, the origin of petals, stamen insertion pattem and monocarpellary pistil were discussed. In addition the floral ontogenetic characters among three genera of the Berberidaceae, i.e., Caulophyllum, Podophyllum and Nanclina were compared. It is inferred that the trimerous-whoded arrangement and the diversity of carpel initiation were the two unique characters of Nandina.

Key words: Nandina, Berberidaceae, Floral organogenesis, Ontogeny, Systematic significance