Leafy mosses, representatives, photos and structural features of which will be considered in our article, belong to higher spore plants. These ancient organisms play a significant role in the cover of our planet.
Leafy mosses: a characteristic of a systematic group
These plants are higher. These are the first people to land, therefore, during the development of this new habitat they have new signs. First of all, it is a leaf-stem structure and the presence of mechanical and conductive tissues. Such features contribute to a more efficient course of the photosynthesis process. Leafy mosses, the structure of which is much more complicated compared to algae, have rhizoids instead of roots. This trait "inherited" them from lower plants.
Variety of bryophytes
According to the structural features of the aerial part, mosses can be combined into two groups: thallus and leafy. A typical representative of the first of these is a variable march. This plant has a dichotomously branched thallus of dark green color with brood baskets. Leafy mosses are more common in nature. Their example is Kukushkin flax, which is also called polytrich ordinary. All sphagnum (white) mosses also have a branched shoot.
What is a life cycle?
Leafy mosses are perennials. Throughout their lives, a clear alternation of generations is observed. This is the essence of their life cycle. Both generations differ not only in the features of the external structure, but also in the method of reproduction. This feature of life is characteristic of all representatives of higher spore plants. Moreover, in ferns, horsetails and grouse sporophytes prevail in the life cycle, and in the bryophytes - the sexual generation.
Gametophyte
Leafy mosses, the representatives of which are depicted in the photo, we used to see as a solid green carpet. This is the sexual generation of plants. If you look closely, you can see that it consists of small stems with small sessile leaves of a linear type. Like all mosses, they attach to the substrate with rhizoids. Gametangia are formed on the shoots of leafy mosses, in which germ cells are formed. In the presence of water, they merge, forming the asexual generation of mosses - sporophyte.
Sporophyte
The asexual generation of mosses develops on the green gametophyte. It has the appearance of a thin leg on which the box is located. Inside it, spores develop - asexual reproduction cells. When the box opens, they fall into the soil, germinate and again form the gametophyte, which predominates in the life cycle of mossy plants. Further, the sexual generation forms a zygote, which is divided by meiosis and forms spores. And thus, the life cycle is carried out again. Sporophyte is incapable of self-nutrition, since it practically does not contain chlorophyll in its cells. That is why it is attached to the leafy gametophyte, due to which it feeds. These generations differ in the chromosome set. In sporophyte, it is diploid. But the sexual generation has a single set, since the sex cells merge when the zygotes are formed.
Leafy Mosses: Habitat
Mosses always live in humid places. And this is no coincidence. The fact is that the process of fusion of gametes in these plants occurs only with the help of water. Moist forests, mountainous areas, caves, swamps, tree trunks, roofs, damp basements and rooms, darkened walls of houses ... Mosses have mastered all these habitats. These plants perfectly absorb and retain water. Therefore, their appearance in the natural environment indicates swamping of the territory. Bryophytes react very painfully to a decrease in the amount of moisture. In its absence, they can dry, while maintaining viability. When the humidity is normalized, they absorb it with the whole shoot and again return to normal existence. Thanks to this ability, leafy mosses are more adapted to changing living conditions. Their widespread contributes to the fact that they are not eaten by animals, do not damage bacteria and fungi. This is because, together with water, they absorb toxic and radioactive substances.
The value of mosses
Leafy mosses, primarily sphagnum mosses, play a major role in the waterlogging and formation of peat, which is a valuable fuel mineral, fertilizer, and raw material for the production of alcohols, plastics, acetic acid, naphthalene, and also insulating materials. The process of formation of this substance is quite long in duration: 1 cm of peat forms for as long as 10 years. Absorbing moisture, leafy mosses are regulators of the water balance of the soil, protect it from erosion. However, at the same time, the spread and proliferation of mosses worsens its gas exchange. As a result, plants do not receive oxygen, die off, the process of their decay begins.
So, leafy mosses are the most numerous representatives of this department, which are most adapted to changes in environmental conditions. They are able to absorb moisture throughout the shoot surface, holding it for a long time. Gametophyte prevails in the life cycle of these plants. Asexual generation develops on it, which multiplies through spores.