Abstract
Seven hundred and sixty-six specimens previously identified as Sphagnum girgensohnii were re-examined to check their morphological characters including stem cortex surface, stem leaf apex, stem leaf borders, hyalocysts in stem leaves, number of divergent branches, branch leaf shape, and pores in divergent branch leaves. They were collected from Kamchatka, Sakhalin, Hokkaido, Honshu, Shikoku, and Yaku-Island, and deposited at the Nagano Nature Conservation Research Institute (NAC). Among them, six specimens collected from Nagano Prefecture were confirmed as Sphagnum rubiginosum Flatb., new to Japan.
