Reappraisal of Barbula trifaria var. desertorum (J. Froehl.) S. Agnew (Pottiaceae, Bryophyta), based on morphological and molecular evidence

Abstract

Barbula trifaria var. desertorum, known from SW Asia and southern Italy, has been considered a synonym of Didymodon luridus or a synonym of D. rigidulus. To elucidate its systematic position, we conducted phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer (ITS) and plastid (atpB-rbcL, trnL-F, and trnG) sequences. Based on our morphological and phylogenetic results Barbula trifaria var. desertorum is transferred to the genus Didymodon and recognized at species rank as D. desertorum. The range of this species is extended to most Mediterranean countries and the Canary Islands. The species is described and illustrated, its affinities are discussed and its geographical distribution is mapped.