Abstract

The systematic position of the rare moss Pulchrinodus inflatus (Hook. f. & Wils.) Allen, which is only known in sterile condition, has so far been dubious. The species has been transferred between very distant families of the Bryopsida, such as the haplolepideous Dicnemonaceae (Dicranales) or the diplolepideous Pterobryaceae (Leucodontales). To clarify the systematic relationships of Pulchrinodus at the molecular level, three DNA regions, the cpDNA trnL–F and psbT–H regions and the nrDNA ITS2, were sequenced. The psbT–H region is employed for the first time in the Bryopsida. In maximum parsimony and maximum likelihood trees, Pulchrinodus is clearly separated from the genera Dicnemon, Eucamptodon and Mesotus of Dicnemonaceae. Furthermore, a close relationship to genera of the Pterobryaceae (Hildebrandtiella, Pterobryon) is also not indicated. The molecular data, therefore, contradict a position of Pulchrinodus either in the haplolepideous mosses or in the Hypnales (today including the Leucodontales). Instead, the placement of Pulchrinodus in the molecular trees, near to species of the Rhizogoniaceae and Orthotrichaceae, together with its unique combination of gametophytic characters, indicates that Pulchrinodus occupies an isolated position in a grade diverging early within the diplolepideous mosses.