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
Sphagnum all other land plants, has an alternation of generations; like other bryophytes, the haploid gametophyte generation is dominant and persistent. Unlike other mosses, the long-lived gametophytes do not rely upon rhizoids to assist in water uptake. "Sphagnum" species can be unisexual (male or female, dioecious) or bisexual (male and female gametes produced from the same plant; monoecious); In North America, 80% of "Sphagnum" species are unisexual. Gametophytes have substantial asexual reproduction by fragmentation, producing much of the living material in sphagnum peatlands. Swimming sperm fertilize eggs contained in archegonia that remain attached to the female gametophyte. The sporophyte is relatively