The vegetative and reproductive morphology of some parasitic Janczewskia Solms-Laubach species including the type species was examined based on specimens collected from various localities around the world. In J. gardneri Setchell et Guernsey on Osmundea spectabilis (Postels et Ruprecht) Nam from California, secondary pit connections are not found between epidermal cells and vegetative axial cells have two pericentral cells. As its host, J. gardneri also has a typical filament type male structure in an apical urn-shaped pit of branches rather than the trichoblast type in other species including the type J. verruciformis Solms-Laubach and tetrasporangial origin of epidermal cells rather than pericentral cells. These significant differences between the species suggest that J. gardneri should be separated from the genus Janczewskia. Based on this morphological data, the section Heterojanczewskia Setchell including J. gardneri, together with an emendation of the generic delineation of Janczewskia, is elevated to the genus level. Relevant nomenclatural changes for some Janczewskia species are also included here.

Abstract
INTRODUCTION
MATERIALS AND METHODS
RESULTS AND DISCUSSION
ACKNOWLEDGEMENTS
REFERENCES

• Ki Wan Nam(Department of Marine Biology, Pukyong National University, Busan 48513, Republic of Korea) Corresponding Author