Data from: Genomic and phylogenetic structure of the Sphagnum imbricatum complex (Sphagnaceae, Bryophyta)

New sequence data from a RADseq study of genetic variation within Sphagnum subgenus Sphagnum. Sphagnum imbricatum sensu lato (Sphagnum, subgenus Sphagnum) is sometimes considered a single widespread and polymorphic species, or up to four separate species. This study was conducted to provide a phylogenetic delimitation of the S. imbricatum complex, assess species delimitation within the complex, and evaluate likely parentage of five allopolyploid species in subg. Sphagnum that may be related to haploid species. RADSeq data were assembled from samples of subg. Sphagnum plus three outgroup taxa from related Sphagnum subgenera. Parentage of allopolyploids was assessed using STRUCTURE and differentially fixed SNPs among haploid taxa, and their distribution within and among the allopolyploids. The S. imbricatum complex was circumscribed to include S. austinii, S. imbricatum, S. portoricense, and S. steerei. The last traditionally recognized species, S. affine, was resolved to include two morphologically cryptic clades that are phylogenetically divergent (nonsister groups) within the complex. Consistent hypotheses for parentage of the allopolyploids were obtained from STRUCTURE and fixed SNP analyses. All of the northern allopolyploids were derived from crosses between species in the S. imbricatum and S. magellanicum complexes. Our results further suggested hypotheses about specific haploid taxa as putative parents of the allopolyploid species