XVI International Botanical Congess

Sphagnum has traditionally been divided into four large sections and a series of monotypic or small sections. The purpose of this research is to determine polarity of evolutionary change in Sphagnum by rooting a generic phylogeny using a variety of potential outgroup taxa, and to assess relationships among the major and minor sections. Nucleotide sequence data from the psbt (cpDNA) and 26S (nrDNA) genes suggest that the section Subsecunda is sister the rest of Sphagnum. Sequences from the ITS (nrDNA) and trnL (cpDNA) regions indicate that the Cuspidata, Acutifolia, and Sphagnum are monophyletic if defined to include several of the smaller sections. S. tenellum (sect. Mollusca) and S. pylaisii (sect. Hemitheca) are nested within the Cuspidata, S. wulfianum (sect. Polyclada) is nested within the Acutifolia, and S. aongstroemii (sect. Insulosa) is sister to a clade that otherwise includes the Acutifolia.