Patterns of clade support across the major lineages of moss phylogeny

Relationships among the major branches of moss phylogeny are understudied compared with other major land-plant groups. We addressed this by surveying 14-17 plastid genes from taxa representing the major lineages, using different phylogenetic methods (parsimony, likelihood) and codon- and gene-based data partitioning schemes (likelihood). Our phylogenetic inferences generally corroborated the best supported clades across multiple recent studies, with comparable or higher levels of clade support here. We resolved persistent ambiguities with strong to moderate support across analyses, including several early nodes in subclass Dicranidae, and relationships among other subclasses of peristomate mosses. In particular, we resolved a sister-group relationship between Bryidae and Dicranidae, between these subclasses and Timiidae, and between this entire clade and Funariidae. We consistently recovered Tetraphidopsida (a nematodontous class) as the sister group of arthrodontous mosses (Bryopsida), although with only weak support. Strongly conflicting arrangements at the base of moss phylogeny concerning Takakiopsida and Sphagnopsida, two non-peristomate moss lineages, were inferred in parsimony and likelihood analysis, but this depended on how base-frequency parameters were estimated and how data were partitioned in likelihood analysis. Relationships inferred for the remaining peristomate and non-peristomate moss clades, and their associated support values, were otherwise broadly congruent across analyses.