Phylogenetic Relationships Within the Haplolepideous Mosses

Abstract

Mosses with haplolepideous peristomes form a major lineage within the arthrodontous taxa, the Dicranidae. Relationships among lineages within the Dicranidae are explored using three cpDNA regions: rbcL, rps4, and the region spanning trnL(UAA)- trnF(GAA). Maximum parsimony analyses of combined data sets support robust clades that correspond to traditionally recognized families. Phylogenetic relationships of 71 exemplar taxa rooted with five outgroup taxa identify 13 major clades within the Dicranidae. Predominantly the monophyly of these groups is strongly supported, although relationships among the clades are ambiguous. The phylogenetic implications of the current taxon sampling include 1) the Dicranidae are monophyletic, 2) the Pottiales are polyphyletic with the Calymperaceae and Octoblepharaceae cladistically distant from the Pottiaceae, and these two former families should be transferred to the Dicranales, 3) the Dicranales are polyphyletic, with Ditrichaceae and Rhabdoweisiaceae more closely related to the Pottiaceae than other members of the Dicranales, 4) the Fissidentaceae are nested within the Dicranales, 5) the Rhachitheciaceae and Erpodiaceae are nested within the Dicranidae and sister to the Pottiaceae, 6) Amphidium is sister to the pottiaceous clade, 7) the Seligeriaceae form a well supported sister relationship to the Grimmiales, and 8) Scouleria aquatica, Bryoxiphium norvegicum, Ditrichum flexicaule, and Timmiella crassinervis appear to form basal lineages within the Dicranidae.