The Plant body is a gametophyte. They grow in areas which arc in between the aquatic and terrestrial habitats i.e. amphibious zone and hence known as amphibious plants. They have thalloid or leafy multi cellular green plant body. The smallest form is microscopic (e.g. Zoopsis). The largest genus recorded so far is an Australian Dawsonia which is about 70 cms in length. The dominant plant body is gametophyte (n) which is independent. The plant body lacks true roots, stem or leaves. Rhizoids - (root like structure) serve the function of roots. The plants are green and possess chloroplasts. They show autotrophic mode of nutrition. Vascular tissues are completely absent.
Sexual reproduction is oogamous. Sex organs are multi cellular and jacketed.Male reproductive organ is known as antheridium. It is a club shaped structure being borne by a narrow stalk. It produces biflagellate and motile male gametes or antherozoids. The female sex organ is known as archegonium. It is a flask shaped structure having a swollen base and a narrow neck.Gametophyte and sporophyte differ in form which alternate with each other, thus heterologous alternation of generation is seen in Bryophytes.