On the taxonomic position of the genera Brachydontium Fürnr. and Campylostelium Bruch & Schimp. (Bryophyta, Grimmiales)

Abstract

The genus Brachydontium was placed in the family Seligeriaceae by most recent authors, in spite of the fact that some of its morphological characters contrast with other genera in this family. The genus Campylostelium was traditionally included in the Ptychomitriaceae, until Hernández-Maqueda et al. (2008) suggested resurrecting the monogeneric Campylosteliaceae De Not. based on data obtained from phylogenetic analyses of two chloroplast markers. Our phylogenetic reconstructions based on chloroplast rps4 and mitochondrial nad5 recovered Brachydontium trichodes (F.Weber) Fürnr. and B. olympicum (E.Britton) T.T.McIntosh & J.R.Spence in a strongly supported clade sister to the Ptychomitriaceae, whereas a well- supported clade composed of Campylostelium saxicola (F.Weber & D.Mohr) Bruch & Schimp. and C. pitardii (Corb.) E.Maier was resolved in a sister position to Brachydontium plus Ptychomitriaceae. The well- supported clade of these three groups is sister to the Grimmiaceae. Results of our phylogenetic analysis and re-evaluation of morphological characters suggest transfer of Brachydontium to the Ptychomitriaceae and confirm the placement of Campylostelium in this family. Based on the inferred affinities of Brachydontium and Campylostelium we propose a new circumscription for the family Ptychomitriaceae.