Sphagnum such gemmae. Peat moss can be distinguished from other moss species by its unique branch clusters. The plant and stem color, the shape of the branch and stem leaves, and the shape of the green cells are all characteristics used to identify peat moss to species. "Sphagnum" taxonomy has been very contentious since the early 1900s; most species require microscopic dissection to be identified. In the field, most "Sphagnum" species can be identified to one of four major sections of the genus—classification and descriptions follow Andrus 2007 (Flora North America): The reciprocal monophyly of these sections and two other minor
Sphagnum short-lived, and consists almost entirely of a shiny green, spherical spore capsule that becomes black with spores. Sporophytes are raised on stalks to facilitate spore dispersal, but unlike other mosses, "Sphagnum" stalks are produced by the maternal gametophyte. Tetrahedral haploid spores are produced in the sporophyte by meiosis, which are then dispersed when the capsule explosively discharges its cap, called an operculum, and shoots the spores some distance. The spores germinate to produce minute protonemae, which start as filaments, can become thalloid, and can produce a few rhizoids. Soon afterwards, the protonema develops buds and these differentiate into its characteristic,