If one walks through an area with mosses and ferns,one is seeing a bryophytes which has stages namely gametophyte and sporophyte. The plants undergo stages which has a haploid gametophyte and a diploid sporophyte. For mosses, it is the gametophyte that acts as the main stage while in ferns it is the sporophyte. Gametophytes have gametes called gametangium while the sporophyte have spores namely sporangium.
