The first land-dwellers that currently grow are mosses. Biology has a separate direction for the study of this group - bryology. Scientists suggest that life originated in water. Over time, algae acquired traits that helped them survive in drought conditions. Further evolution led to the emergence of spore land plants.
Characteristic features of the structure
Bryosophytes are higher plants. They have the first plant tissues - groups of specialized cells. It is the basic and photosynthetic tissue. Since conductive and mechanical tissues are absent, the body of mosses is represented by a thallus, similar to algae. However, it has a leafy structure. The function of attaching to the substrate and absorbing water with nutrients is carried out by rhizoids. They differ from true roots in the absence of tissue.
Bright representatives of this group of plants are moss "phoenix", "cuckoo flax", sphagnum, marchantia.
Life cycle
Bryosophytes are capable of asexual and sexual reproduction. Therefore, in their life cycle there is a clear alternation of generations - sexual (gametophyte) and asexual (sporophyte).
Moss gametophyte is a small stalk with leaves, on which germ cells - gametes develop. During the fertilization process, eggs are fertilized by sperm. This requires the presence of water. That is why mosses always grow in moist areas of the soil. As a result, an embryo is formed, which develops into an asexual generation. The sporophyte grows on the gametophyte and is a filamentous dry leg with a box. Inside it are spores - cells of asexual reproduction. They spill out of the box, germinate, and the leaf-stem gametophyte is re-formed. It is not difficult to guess that it is the sexual generation that predominates in the life cycle of mosses. Since everyone is used to what it looks like a green soft carpet.
Classes of mosses
The classification of moss is based on the difference in the anatomical and morphological features of the structure of these organisms.
Green mosses are unique plants. So, moss "cuckoo flax" is able to absorb water 4 times its own size. Their color is greenish-brown, they are mostly perennial plants. They grow very quickly, covering any surface with a solid green carpet - soil, asph alt, roofs. The only condition is the constant presence of moisture. Because without water, these organisms cannot reproduce.
Some of them, like moss"phoenix" are able to live in water. This beautiful plant got its name because of the resemblance to the tail of the famous mythological Phoenix bird. It is absolutely unpretentious, survives even in hard water with any light intensity. Since it was brought from America, the optimum water temperature is also not fundamental and ranges from 18 to 30 degrees. Moss "phoenix" looks like a beautiful green fountain, "pouring" from the decorative snags of the aquarium.
White or peat mosses are most often found in swamps. A representative of this group of mosses is sphagnum. It has a characteristic structure of leaves, which consist of two types of cells. The former have a typical structure and contain green plastids - chloroplasts that carry out photosynthesis. The second ones are larger, dead, transparent. They are located between chlorophyll-bearing cells. They are essential for the plant. Absorbing a large amount of water, they are able to keep it in their cavities for a long time, if necessary, giving it to living cells. Where sphagnum settles, the soil quickly begins to become waterlogged.
Meaning of bryophytes
Green mosses, along with other groups of bryophytes, are powerful moisture accumulators. Their appearance serves as a serious signal of the beginning of waterlogging of the soil. On the one hand, this process significantly reduces the area of free arable land. On the other hand, it serves as a condition for the formation of peat. This valuable mineral is used as fuel, fertilizer, raw material for the chemical industry. Manyrepresentatives of this group of plants have a very attractive aesthetic appearance. So, moss "phoenix" is used for the design of aquariums. Mosses are able to release special substances - acids. They can break down hard rocks, promoting soil formation.
