Ordinal relationships of pleurocarpous mosses,with special emphasis on the Hookeriales

Sequence data from four DNA regions, namely, chloroplast trnL‐trnF and rps4, mitochondrial nad5, and nuclear 26S rDNA, were surveyed from 89 taxa traditionally associated with the Hookeriales, five Hypnales and five outgroups. Phylogenetic reconstruction was performed using the maximum parsimony and maximum likelihood optimality criteria and by Bayesian phylogenetic inference. Thirteen morphological characters were optimized on the resulting phylogeny using maximum likelihood. Inferences of character evolution based on the molecular phylogeny suggest that (1) the core of pleurocarpous mosses (i.e. the Hypnanae) is best defined and thus distinguished from the Ptychomnianae by smooth rather than furrowed capsules, (2) a synapomorphy for the Ptychomnianae is the short and double (or absent) costa and (3) the Hookeriales are defined by undifferentiated alar cells. The Ptychomniaceae plus Garovagliaceae are recognized as a single family in its own order, the Ptychomniales ord. nov. and superorder, the Ptychomnianae, superord. nov. This superorder is sister to the combined Hypnales and Hookeriales, i.e. the Hypnanae. The Hookeriales are interpreted as consisting of seven families, the Hypopterygiaceae, Saulomataceae fam. nov., Daltoniaceae, Schimperobryaceae fam. nov., Hookeriaceae, Leucomiaceae and Pilotrichaceae. The Adelotheciaceae are embedded within the Daltoniaceae and considered synonymous with that family. Within the Ptychomniaceae, Ptychomniella is raised from a subgenus of Ptychomnion to generic status. Euptychium setigerum and its monospecific section, Crassisubulata, are transferred to Garovaglia. Callicostella diatomophila is transferred to Diploneuron. Additional alterations at the generic level await more data.