Phylogenetic Analyses of Timmiaceae (Bryophyta: Musci) Based on Nuclear and Chloroplast Sequence Data

Nuclear ribosomal (26S) and chloroplast (trnL-trnF and atpB-rbcL spacer) genomic regions were sequenced from 29 exemplars of Timmiaceae and five outgroup taxa. Phylogenetic hypotheses were tested from analyses of the individual regions and a combined dataset, using both parsimony and Bayesian inference methods. Estimates of branch support were established using bootstrap analyses and Bayesian posterior probabilities. The analyses were used to test the monophyly of the species and the relationships among taxa in Timmiaceae, previously based on morphology. Phylogenetic inferences suggest that Timmia austriaca, T. megapolitana s.s., T. megapolitana subsp. bavarica, and section Norvegica represent monophyletic taxa. Timmia norvegica s.s., T. norvegica var. excurrens, and T. sibirica were non-monophyletic, but together form a single clade. We, therefore, recommend recognizing them as a single taxon, T. norvegica. A key to the taxa is presented.