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
What Is and What Should Never Be What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second track on "Led Zeppelin II" (1969). "What is and What Should Never Be" was one of the first songs on which Page used his soon-to-become trademark Gibson Les Paul for recording. The production makes liberal use of stereo as the guitars pan back and forth between channels. Robert Plant's vocals were phased during the verses. Record producer Rick Rubin has remarked, "The