Abstract: The seasonal changes of the ray and phloem parenchyma cells of secondary phloem in terminal branchlets of Dalbergia odorifera T. Chen (Papilionaceae), a tropical deciduous tree, were studied by using transmission electron microscopy. The changes were mainly the cyclic alternation of accumulation and ex-haustion of the storage materials including proteins in the central vacuole, the starch grains, lipoid globules and phytoferritin in the plastids, and lipoids in the spherosomes. D. odorifera did not undergo some of the cytological changes which were found in the temperate trees studied and believed to be related with the hardi-ness. Like the stuctures found in temperate trees, in D. odorifera the highly folded plasmalemma and nu-merous small vesicles pinched of by the plasmalemma appeared in the actively reserve - accumulating cells during the leaf- fall period. It was suggested that the structures play a role in translocation of the materials between the cells, while in the temperat trees the structures were considered involving in frost resistance.

Key words: Tropical tree