A nomenclatural rectification in the widespread East Asian species of Dilutineuron (Bryophyta, Grimmiaceae)

A taxonomic and nomenclatural history of the two East Asian species, Dilutineuron anomodontoides and Racomitrium canaliculatum, is presented. The name of the latter species was validly published in 1905 and it antedates by three years the name of the former species which was validly published in 1908. Accordingly, a new combination, Dilutineuron canaliculatum, is proposed and this is the correct name for the widely distributed East Asian species known until now as D. anomodontoides. Racomitrium anomodontoides, R. bandaiense, R. bandaiense var. ramosum, R. fasciculare var. brachyphyllum, R. fasciculare var. erosum, R. fasciculare var. perrobustum, R. formosicum, R. nipponicum, and R. yakushimense are considered to be new synonyms of Dilutineuron canaliculatum. Racomitrium hedwigioides is an illegitimate name because it applied to the species including the type of the earlier name R. canaliculatum which was considered as R. hedwigioides var. canaliculatum.