Plains, horsetails, ferns: structure, differences. How does a person use horsetails, mosses and ferns?

The plains, horsetails, ferns represent a group of the first terrestrial plants. Despite the fact that they arose more than 400 million years ago, these plants have received sufficient distribution in the modern period. The structure of the plains, horsetails and ferns, the features of their vital activity and biological significance will be considered in our article.

Exit plants to land

There is a theory that all living organisms, including plants, originated in the aquatic environment. The first of these were algae. Over time, environmental conditions have changed significantly, and algae have had to adapt to the transfer of prolonged periods of drought. As a result, they gave rise to the first terrestrial plants. Even in the school course of botany, ferns, horsetails, and plaunas (6th grade) are regarded as descendants on land.

The extinct group of the first terrestrial plants are the representatives of the rhinophyte department. Their low shoots were devoid of leaves and forked brittle. And instead of roots rhyniophytes had rhizoids, by means of which they were attached to the substrate.

Plaunids, horsetails, ferns - the highest spore plants

Modern spore plants have a more complex and perfect structure. Plaunids, horsetails, ferns, like all representatives of this systematic group, are formed by real tissues. Thanks to their appearance, it became possible for plants to land on land. Fabrics form organs: root and shoot. This is their main difference from the lower plants, which consist of unspecialized cells.

Reproduction of these organisms occurs with the help of cells of asexual reproduction - a spore. Getting into the soil, they germinate.

The concept of the life cycle

All higher spore plants have a complex life cycle. This is the period between two identical phases of development. It is he who ensures the continuity of life of a specific biological species. In the life cycle of spore plants there is an alternation of generations - sexual and asexual. Sometimes they differ from each other in appearance.

The plant on which spores are formed is a sexless generation. It is predominant in mosses. From the dispute grows an individual of the sexual generation - gametophyte. The main differences between the plains, horsetails and ferns are its predominance.

Let's consider each of the departments of higher spore plants in more detail.

Department of the Plain-like

These are evergreen herbaceous plants growing in moist places. In most cases they are perennial. Plains have creeping stems, which forked branch. On them on a spiral small leaves are fastened.

The root system is formed by additional roots that extend straight from the stems. In the area of the tips of shoots are scales, which are modified leaves. They are the organs of asexual reproduction - sporangia.

Features of the structure of horsetail

Modern types of horsetails are also perennial herbaceous plants. Their characteristic feature is a clear separation of the shoot to the nodes to which the tooth-like leaves are attached. At the base they coalesce, forming a peculiar vagina. At the nodes there are cells of the educational tissue, due to which there is an intercalary growth of horsetails in height. Underground organ of horsetails is a rhizome, also divided into internodes. The function of photosynthesis in these plants is performed by a ribbed stem. Inside it there are many cavities filled with water and oxygen.

Sporophyte horsetails are green shoots that look like small young pines. A gametophyte exists separately and has the appearance of a green plate. One of the most common species of this department - horsetail field - has two types of shoots. The first is called spring, it is not capable of photosynthesis and carries sporiferous spikelets. Summer, green, vegetative.

General characteristics of fern-like

What is the difference between ferns and horsetails? The answer is obvious. This department is the most numerous and diverse, and its modern representatives have a more complex structure in comparison with horsetails and plaunas. Among the 10,000 species that grow at a given time, there are grasses, bushes, and trees.

The group of equisporous ferns is represented by aquatic inhabitants - it is a salvina floating and a four-leaved martilia. They freely adhere to the surface of water bodies with a small current. In the tropics, an aquatic fern of azole is widespread, which forms a symbiosis with cyanobacteria capable of assimilating atmospheric nitrogen.

Rasposporovye ferns grow in moist and shady forests. Their typical representatives are Common Eagle, Male Shield, Female Kochetnik and other species.

It is about such plants that an amazing legend goes that the fern flower found on the night of Ivan Kupala will be endowed with an amazing gift - it will learn to understand the language of all living beings. However, from the point of view of biology, this is impossible. Higher spore plants, including ferns, do not form flowers and fruits.

How a person uses horsetails, mussels and ferns

Higher spore plants have long occupied their niche in nature and human life. Ferns are part of a large number of plant communities, used to create landscape decor and as medicinal plants. But the most important role of these plants in nature lies in the formation of valuable mineral - coal.

In antiquity, all spore were giant trees. When they died, their trunks under conditions of lack of oxygen and high pressure of the earth's layers turned into coal.

As a person uses horsetails, mosses and ferns, one can easily imagine using the example of medicine. They are all valuable medicinal plants. For example, the horsetail field has a hemostatic and diuretic effect. One of the representatives of the department of the lycopodium - common lamb - is used as a means to combat alcoholism.

Spores of these plants have long been used for the manufacture of pyrotechnic products. In the pharmaceutical industry, the flocks are also used to pellet tablets and to make baby powder.

The main importance of higher spore plants is still in the formation of coal. This valuable mineral has long been an important source of energy, since a large amount of heat is released during its combustion. The power industry of many countries is based precisely on this raw material.

Thus, the flocks, horsetails, ferns represent a group of higher spore plants, which is widely represented by fossil and ancient species. They are the first to come to the land, which became possible due to the appearance of more progressive features of the structure: tissues and organs.