Sphagnum erect, leafy, branched gametophyte with chlorophyllose cells and hyaline cells. This stage dominates the environment where "Sphagnum" grows, obliterating and burying the protonema and eventually building up into layers of dead moss called peat. Carpets of living "Sphagnum" may be attacked by various fungi, and one fungus that is also a mushroom, "Sphagnurus paluster", produces conspicuous dead patches. When this fungus and other agarics attack the protonema, "Sphagnum" is induced to produce nonphotosynthetic gemmae that can survive the fungal attack and months later germinate to produce new protonema and leafy gametophytes. It is unknown whether the leafy stage can produce
Moss Antarctica and Russia, and a case is put forwards for Carboniferous mosses. It has further been claimed that tube-like fossils from the Silurian are the macerated remains of moss calyptræ. Mosses also appear to evolve 2–3 times slower than ferns, gymnosperms and angiosperms. Recent research show that ancient moss could explain why the Ordovician ice ages occurred. When the ancestors of today's moss started to spread on land 470 million years ago, they absorbed CO from the atmosphere and extracted minerals by secreting organic acids that dissolved the rocks they were growing on. These chemically altered rocks in turn reacted