It shows the beginnings of differentiation of stem and leaves - but no roots. The stem shows some internal differentiation into hydroids and leptoids which are like xylem and phloem of higher plants but very simply organized with no connection to leaves or branching stems. Male and female gametophytes look identical except when they produce reproductive structures. The male plant produces clusters of antheridia which contain thousands of ciliate sperm. The female produces archegonia, each containing a single egg.
Fertilization is dependent on water - sperm are splashed or swim to the archegonia.
It is a leafless stem with a seta or foot at one end, drawing nutrients from the gametophyte. At the other end is a capsule in which meiosis occurs to form spores. The archegonium grows around the developing sporophyte for a while but becomes separated from the gametophyte and is carried up to form a cap or calyptra over the sporangium. Curiously, the sporangia of some mosses have stomata much like those on the leaves of vascular plants. The calyptra is lost when the sporangium is mature as is the operculum or lid on the end of the capsule.