Plants of the division Bryophyta are divided into three classes.
1. Hepaticae: Liverworts or liver plants are those moss-like plants or gametophytes with liver-shaped leaves.
(i) They are gametophytic plants. The body is thallus in nature.
(ii) Their genitalia are located on the surface of the thallus. Pungdhani is pear shaped and stridhani is flask shaped.
(iii) They are small independent plants. Less than 10 cm in length and 2-20 mm in width.
(iv) They are widespread all over the world. It has 6,000 species in polar, desert and humid regions.
(v) They grow on soil, sand, stone, tree or any object.
A few liverworts- Riccia huebeneriana, Marchantia polymoroha, Asterella californica, Ricciocarpus natans.
2. Anthocerotae: Hornworts are hornworts in which the sexual structure of mosses or gametophytes is horn-shaped.
(i) Their main plants are gametophytes. It is green and flat in structure.
(ii) Their sporophytes are partially self-sustaining.
(iii) They are developed and have columnar capsules.
(iv) Their thallus is heterolateral and recumbent. The genitalia are rooted on the surface of the thallus.
(v) They are found all over the world. Their number of species is 300.
Some hornworts- Anthoceros agrestis, Phaeoceros carolinianus, Ceratophyllum pollination, Folioceros amboinensis, Dendroceros crispus, Notothylas anaporata.
3. Musci
(i) They are known as mosses.
(ii) Their gametophytes are cylindrical or thallus shaped and develop into protonema.
(iii) Their body is more like a stem and the genitalia are formed at the tip of the stem.
(iv) Their sporophytes are divided into pods, setae and capsules.
Examples: Funaria, Sphagnum, Pogonatum.