Polytrichum commune moss seen from directly above. The brown structures are male sexual organs, which produce sperm. Mosses have a more primitive means of reproduction than higher plants, and do not produce flowers or seeds. The main body of a moss plant, the gametophyte, grows from a single spore. Male and female sex organs develop on the gameto- phyte, and produce sperm and eggs. In Polytrichum the male organs are much more conspicuous than the female organs. The sperm swim through a film of moisture on the plant's surface to the female org- an, where the egg is then fertilised to form the sporophyte (not seen). This grows on a stalk on top of the gametophyte and produces new spores.