* Do not have real roots, but rhizoids.
* Have a leaf-stem structure.
* The dominant generation is the GAMETOPHITE - the sexual generation.
* Fertilization depends on water.
* Sporophyte and gametophyte are one plant (sporophyte is parasitic on gametophyte).

As in all higher plants, there is an alternation of generations in mosses. During one life cycle, the haploid gametophyte in the antheridia forms spermatozoa, which with the flow of water reach the archegonia and merge with the egg into a diploid zygote. The zygote grows into a diploid sporophyte, a generation that reproduces asexually. As a result of meiosis, haploid spores appear on the sporophyte, from which haploid gametophytes germinate, and everything repeats itself again.

In Bryophyta, the gametophyte is the dominant generation, and the sporophyte, developing and feeding at the expense of the gametophyte, is completely dependent on it (the tests say that the sporophyte is a parasite on the gametophyte). Spores are formed in spore boxes that rise above the gametophyte on a thin stalk (box on a stalk).

Class Hepaticae
These are lower forms of Bryophytes. They are more simple in structure than mosses and more confined to damp and shady habitats. They have an undifferentiated thallus. Protonemal stage is absent. Sporophyte is very simple and short lived . In some forms sporophyte is differentiated into foot, seta and capsule. Eg. Marchantia. In some the foot and seta are absent. Eg. Riccia.

Class Musci
They have a more differentiated structure than liverworts. They often form dense cushions. These are higher forms in which the gametophyte is differentiated into ‘stem’ like and ‘leaf’ like parts and the former showing radial symmetry. Rhizoids are multi-cellular and branched. Protonemal stage is present. Sporophyte is differentiated into foot, seta and capsule Eg. Funaria.

Sphagnum is a common name for different (primarily by color) types of mosses: “white moss”, “brown moss”, “red moss”, etc. Common to all mosses is that, living on very wet soils, they accumulate in leaves and there is a lot of water in the surface layers of the stems. These tissues consist of cells devoid of plasma content, and the movement of water through them occurs according to the law of capillarity of special elongated cells located one above the other. Sphagnum mosses do not have roots and rhizoids, and thanks to the water-bearing cells, sphagnum leaves have a hygroscopic property, that is, they are able to retain water.

Sphagnum mosses play an important role in the formation and life of bogs. Peat deposits are formed from the dead remains of sphagnum. Sphagnum moss grows at the top of the stem, and its lower part dies. Thus, for many years, huge deposits of peat are formed – 1 cm in 100 years. The process of peat formation occurs due to stagnant overmoistening, lack of oxygen and the creation of an acidic environment by mosses (sphagnol, a bactericidal substance). These conditions are unfavorable for the processes of decay, which prevents the decomposition of sphagnum. Peat is a valuable raw material for obtaining wax, paraffin, ammonia, alcohol, etc. It is used in medicine, in the construction industry, as fuel, fertilizers.

Over the past 300 years, well-preserved human bodies have been discovered in abandoned peat bogs in Britain, Ireland, the Netherlands, Germany and Denmark. Most of these “bog mummies”, or swamp bodies, date back to the 1st century. to n. e. – IV century N. e. The oldest of them belongs to the Mesolithic era (about 10,000 years ago), but there are also medieval and modern finds. The amazing preservation effect of the bog prevented the destruction of the ancient remains. Although the skeletons of the mummies were mostly destroyed, their skin, internal organs (remains of food were even found in the stomachs!), Eyes, eyebrows and hair were well preserved. The bog consists of 90% water with a high content of peat (sphagnum) acids. Such an environment slows down the growth of bacteria, which is why bodies of organic origin, drowned in the swamp, do not decompose. The presence of acids in the swamp, combined with the low temperature of the water and the lack of oxygen, has a tanning effect on the skin, which explains the dark brown color of the bodies found.

Cuckoo flax (Polytrichum). A genus of plants from the class of leafy mosses. About 100 species, in the mountains, forests, swamps and tundra. Most often, the species Polytrichum commune, common in swampy taiga forests, is called cuckoo flax.

The stem, densely covered with leaves with assimilation plates on the upper side of the leaf, reaches a height of 40 cm. It sporulates abundantly. The spore box is located on a long stalk and has a different structure than that of other leafy mosses; from above, it is covered with a cap with thin, downward-directed hairs that resemble linen yarn (hence the name). The ability to form sod and the structure of the leaves determine the surface accumulation of moisture and lead to waterlogging.