A taxonomic study on <i>Saxifraga</i> ser. Radioflorae (A. M. Johnson) Zhmylev (Saxifragaceae) in Japan, the Kuril Islands and Kamchatka.
10 March 2016
Fukuda, Tomoko; Taran, Aleksandr; Okrugin, Viktor; Takahashi, Hideki; Ikeda, HiroshiPlants of Saxifraga ser. Radioflorae (A. M. Johnson) Zhmylev, including Saxifraga fusca Maxim. and Saxifraga purpurascens Kom. (Saxifragaceae), distributed from Kamtchatka to southern Japan through the Kurile Islands, are taxonomically revised on the basis of morphological variability. The findings suggest that the plants from Kamchatka to Japan can be divided into three groups: those from Kamchatka and the Northern Kurils; those from Kunashiri to Japanese archipelago, through Hokkaido and Honshu; and those in the Southern Kurils from Chirpoi to Etorofu. Leaf characteristics and habitat preferences also correlate with these groupings. The first group is identified as Micranthes ohwii (= Saxifraga purpurascens Kom.), and the second group as M. fusca. The third group is similar to M. fusca in floral proportions, but has larger floral discs, unreflective petals, and floral parts developing throughout anthesis. The third group may be derived from M. fusca, adapted to the coastal environment.