Sphagnum ones ("Rigida" and "Squarrosa") has been clarified using molecular phylogenetics. All but two species normally identified as "Sphagnum" reside in one clade; two other species have recently been separated into new families within the Sphagnales reflecting an ancestral relationship with the Tasmanian endemic "Ambuchanania" and long phylogenetic distance to the rest of "Sphagnum". Within main clade of "Sphagnum", phylogenetic distance is relatively short, and molecular dating methods suggest nearly all current "Sphagnum" species are descended from a radiation that occurred just 14 million years ago. "Sphagnum" mosses occur mainly in the Northern Hemisphere in peat bogs, conifer forests, and moist
Sphagnum fuscum Endangered species lists within some German states. Switzerland has labelled "S. fuscum" as vulnerable. In the United States, "S. fuscum" is reported to be at risk in the state of North Carolina. Across Europe, "S. fuscum’s" habitats are under protection. Germany and Switzerland have both placed the moss under “special protection.” This species is associated with "Sphagnum angustifolium", "S. fallax", "S. magellanicum", "S. papillosum", more infrequently with "S. teres", and "S. warnstorfii" in richer sites. "Sphagnum fuscum" is easily discernible from other species of Sphagnum, as it tends to be reddish brown in color, and is more likely to form