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
Scheuchzeria species was known from, and only one where it currently occurs; it is extinct at a few other wetland sites further south in Britain, being found in pools and west hollows of ancient undisturbed Sphagnum bogs. Scheuchzeria Scheuchzeria palustris (Rannoch-rush, or pod grass), is a flowering plant in the family Scheuchzeriaceae, in which there is only one species and Scheuchzeria is the only genus. In the APG II system it is placed in the order Alismatales of the monocots. It is a herbaceous perennial plant, native to cool temperate regions of the Northern Hemisphere, where it grows in wet "Sphagnum"