Listostebelnye mosses: representatives, features of a structure and the organization

Listostebelnye mosses, representatives, photos and features of a structure which will be considered in our article, concern to the higher spore plants. These ancient organisms play a significant role in the cover of our planet.

Listostebelnye mosses: a characteristic of a systematic group

These plants are the highest. These are the first people on land, therefore, during the development of this new habitat, they have new signs. First of all, this is a leaf-building structure and the presence of mechanical and conducting tissues. Such features contribute to a more efficient process of photosynthesis. Listostebelnye mosses, whose structure is considerably complicated in comparison with algae, have rhizoids instead of roots. This trait "got" him from the lower plants.

Variety of bryophytes

According to the features of the structure of the above-ground part, mosses can be combined into two groups: thallus and leaf-stalk. A typical representative of the first of these is a changeable march. This plant has a dichotomically branched thallus of dark green color with broods. Listostebelnye mosses are more common in nature. Their example is Kukushkin flax, which is also called polytrius vulgaris. All sphagnum (white) mosses also have a branched escape.

What is the life cycle

The leafy mosses are perennials. During their lives, there is a clear alternation of generations. This is the essence of their life cycle. Both generations differ not only in the characteristics of the external structure, but also in the way of reproduction. This feature of vital activity is characteristic of all representatives of higher spore plants. And ferns, horsetails and plaunas in the life cycle prevail sporophyte, and in mosses - the sex generation.

Gametophyte

Listostebelnye mosses, whose representatives are depicted in the photo, we used to see as a solid green carpet. This is the sex generation of plants. If you look at it 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. On shoots of leafy mosses, gametangia are formed, in which the sex cells are formed. In the presence of water, they merge, forming an asexual generation of mosses - a sporophyte.

Sporophyte

A half-generation of mosses develops on a green gametophyte. It looks like a thin leg on which the box is located. Inside it, spores develop - cells of asexual reproduction. When the capsule opens, they enter the soil, germinate and again form a gametophyte, which predominates in the life cycle of moss-like plants. Next, the sex 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-feeding, since it practically does not contain chlorophyll in its cells. That is why it is attached to the leaf-stalked gametophyte, due to which it feeds. These generations are distinguished by a chromosome set. He has a diploid sporophyte. But the sex generation has a single set, since the sex cells merge when forming the zygote.

Listostebelnye mosses: a habitat

Mosses always live in wet places. And this is not accidental. The fact is that the process of fusion of gametes in these plants occurs only with the help of water. Wet forests, mountains, caves, swamps, tree trunks, roofs, damp cellars and rooms, darkened walls of houses ... Mosses mastered all these habitats. These plants perfectly absorb and retain water. Therefore, their appearance in a natural environment indicates the swamping of the territory. Bryophytes react very painfully to a decrease in the amount of moisture. In its absence, they can dry out, while maintaining viability. When the humidity is normal, they absorb it with all the escape and again move to normal existence. Due to this ability, leaf-stalk mosses are more adapted to changing habitat conditions. Their wide distribution is promoted also by the fact that they are not eaten by animals, they do not damage bacteria and fungi. This is because, together with water, they absorb toxic and radioactive substances.

The meaning of mosses

Listostebelnye mosses, especially sphagnum, play the main role in the process of bogging and peat formation, which is a valuable fuel mineral, fertilizer, raw material for the production of alcohols, plastics, acetic acid, naphthalene, and insulating materials. The process of formation of this substance is quite long in duration: 1 cm of peat is formed as much as 10 years. Absorbing moisture, leafy mosses regulate 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, 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 surface of the shoot, keeping it for a long time. In the life cycle of these plants, the gametophyte predominates. It develops asexual generation, which multiplies with the help of a dispute.