The genus Glossodium was established by NYLANDER in 1855 as a monotypic genus represented by G. aversum NYL. which was endemic to Colombia, South America. In 1927, ZAHLBRUCKNER described the second species of this genus, G. japonicum ZAHLBR., based on the specimens collected on Mt. Mitsumine, Saitama Prefecture, Japan. We know very few about the distribution of G. aversum NYL., while G. japonicum ZAHLBR. is found at many places in Japan and Saghalien as is shown in Fig. 1 in this paper.
The vertical distribution of G. japonicum ZAHLBR. extends from 800m. above sea level (many localities in Saghalien and a few in Hokkaido and Honsyu) to 1900m. (Mt. Taisyaku in Fukushima Prefecture, Northern Honsyu), but the amplitude of vertical range in the same mountain is not wide.
The substratum of G. japonicum ZAHLBR. is limited with half rotten decorticated trunk base of conifers, such as Abies sachalinensis MAST. and Picea jesoensis CARR. in Saghalien and Hokkaido, Cryptomeria japonica D. DON, Pinus pentaphylla MAYR, Sciadopitys verticillata SIEB. et ZUCC. and Tsuga diversifolia MAST. in Japan Proper.
