Sphagnum magellanicum is one of the most widespread peatmosses commonly used as a model for ecological and evolutionary research. We show that the species has two morphologically and genetically different morphs, associated with different microhabitats in local and global scales.

Populations with phenotypic polymorphism in discrete characters may be good models for investigating genome evolution and speciation. Sphagnum magellanicum is found throughout the Northern Hemisphere, and despite considerable variation in morphological characters it is considered one of the least taxonomically controversial peatmoss species. We have observed two main morphs of the species associated with different microhabitats. We used RAD-sequencing to quantify the genomic divergence between the two morphs and found that genomic differentiation between the two morphs is unexpectedly high.