The sexual life history of a typical moss. A-D a spore germinates, and a protonema emerges (D-E). Gametophores develop from bud-like structures on the protonema (E-F); archegonia and antheridia develop on the gametophore. Fertilization of the egg within the archegonium leads to the development of the sporophyte (G-L). The mature sporophyte dehisces by the release of the operculum (in most taxa) and controls the release of spores by the peristomal teeth (M).