Ferners the structure, development and reproduction of ferns, the life cycle and the value of plants

Modern fervorlike ones belong to vascular plants, which are one of the oldest departments that have preserved a significant variety: it is both modern ferns and the oldest higher plants, whose age is more than 400 million years old.

Fernowshaped plants differ significantly as in their external data, size, life forms and familiar development cycles. Their external characteristics are so specific that their huge number is still called one concept “ferns”, although this department includes the largest group of spore living organisms: it includes almost 5 dozen families, almost six hundred births and almost 11 thousand species of fervor.

So widespread the plants of this department, first of all, were due to the variety of foliage forms, incredible plasticity in the environmental sense, as well as resistance to wet climate and a huge number of disputes.

These plants can be found in any climatic belt: in the forests (in their different tiers), as epiphytes on the branches of large plants, in rocks, in swamps, in any reservoirs, on the walls of houses in megacities, on agricultural lands as weeds: They are almost ubiquitous, but they are used not to attract a lot of attention.

Structure

Fernedlike plants are distinguished by the absence of real leaves, but it is these plants that took huge steps in the direction of their formation.

Education, which in fern resembles foliage, is actually not it; By nature, these formations are a whole structural system of branches that are formed in a single plane.

These formations are called a plane, vaya or prefix. Fern, despite the lack of a fullfledged sheet, has a leaf plate. Everything is simple here these preferences have experienced a flattening that ensures the formation of a plate for the future foliage, which, in fact, does not differ from a similar plate of a fullfledged sheet; However, fern at the moment has not yet managed to form other systems and divide these flat covers into a stem and sheet.

And if we take into account Vayu, then at first glance it is difficult to establish the level of branching where the formation of the stem finishes and where the sheet begins its growth, but you can always clearly track the presence of a sheet plate.

There are no only contours, based on which the unification of sheet plates occurred so that they can get the name of a fullfledged sheet.

The body of any fern consists of several systems:

Fern, who were formed in the forests of the moderate climate zone, usually have a rather insignificant stem. It is represented in the form of a rhizome, immersed in the soil, in which the conductive tissue was significant, and between its kidneys, the cells of the main tissue, which was called parenchymny.

Vaii themselves are located above the surface of the soil and are formed precisely from the rhizome and its kidneys; It is these organs that are characterized by significant apical growth and are able to achieve large sizes.

As a rule, these systems are aimed at performing two important functions of the plant:

Sporangia themselves are formed on the lower parts of the preference and they are responsible for the development of haploid disputes.

The root system of ferns is practically not formed. It is represented by a horizontally formed stem, and subordinate roots are already departing from it. Of their kidneys, pretenses are formed, which, despite all simplicity, are distinguished by a complex structure.

Vaii is unacceptable to call full leaves. Rather, they represent their peculiar pacification, t.e. branches system that are connected to the petiole located at the same level with them.

If we talk about the supporting function, it is provided by the bark of the stems, and since there is no cambium in this area of ​​plants, they are also insignificant, as well as the complete absence of annual rings. If we compare fern with seed plants, then their conductive tissue is developed not so large.

It should be noted that the structure of fern directly depends on their type: sometimes you can find small grassy species that will easily be lost against the background of another vegetation, and sometimes mighty plants can be found, in their appearance resembling trees.

For example, in the tropics of the plants of the Cytechnic family, they can reach a height of up to 20 meters, and their hard subordinate roots, woven among themselves, form a trunk of such a plant.

It is significant that in waterform plants the root system can reach about one meter, while the part located above the water will not be more than 20 centimeters.

Paporotnikov table

Diagram of fern plants

If we talk about the diagram of fern plants, then their development has the following structure:

Paporotnik in the context

Formula of fern plants

Paporotniki are a department of spore plants. For example, one of the most common representatives can be called a shield that sprouts in shady forests and ravines. And on the example of this plant, you can consider the formula of fern.

This plant has perfectly developed rhizomes, in the lower part of which the subordinate roots are formed, and the upper part serves as the basis for the leaves. Grassy fern usually do not have aboveground formations, but have a welldeveloped root system. Their leaves are peristrostanced and quite large, despite the fact that they are prehosts.

The process and formation begins in the spring of the time and usually at the very beginning they are curtailed and snailshaped formations, and after, starting to grow from the ends, straighten and reach enormous sizes.

Signs and characteristics

Paporotykidny are a large group of plants. They form a department and are divided into a sufficiently large number of classes divided into family, and they are characterized by a frequent change in the limits of habitat, which allows not to clarify the family to which the plant can belong, but it is enough to understand that this is a fern. This is quite easy to do, because the fern has quite vivid characteristics and signs that will highlight it from other representatives of the plant world.

At the same time, it is characteristic that the plants of this department differ significantly from more elementary plants below on evolutionary development, as well as from more developed flowering. In plants of this department, the presence of both limiting biological features and more advanced characteristics can be found at the same time.

So, for example, from mosses fernshaped (however, like any other higher plants, from sagoty to flowering) differ in formed vascular tissue specializing in the delivery of fluid and other nutrients to all organs of plants. That is why all their systems, from roots to leaves, are considered to be fullfledged structures. But ferns are not able to form either seeds or flowers. They are propagated by disputes that are formed on the bottom of the foliage.

Most of modern ferns are herbal plants, however, a wet tropical climate can contribute to the formation of even fern trees.

The value of fern plants

Fernedshaped plants, first of all, serve as a food chain and habitat of a huge number of microorganisms and animals, some of these plants are able to form a close symbiosis with cyanobacteria that ensure the absorption of nitrogen, and in their mind this ability can be used as a fertilizer.

One of the most important purpose of fern for human life is that it was these plants (thanks to extinct forms) that participated in the formation of coal deposits, which is currently for all of humanity both fuel and raw materials used in the manufacture of many chemical compounds (plastics , oils, resin).

Ferners are often used as decorative elements: their leaves are used for crafts, and indoor plants are used in interiors.

Some of fern are used for medical purposes. So, from the rhizomes of the panel, you can make an effective antimolestry agent.

Many species of fern are edible. Orlyak leaves, for example (but not in raw form, they can be poisonous), and some of them are used even for construction purposes.

Ferners can be poisonous, and some species can lead to overgrowing of reservoirs, since they are capable of propagated by a vegetative way, which causes significant harm to the environmental system of reservoirs.

Representatives of fern plants

To date, there are more than a thousand species of ferns that can be divided into 300 births and eight subclasses (three of which are recognized as extinct).

The following types are attributed to fern:

Examples of fern with names

Asplenium postitet (fast bone)

Kostenets North

Woodsia Elbskaya

Woodsia is a lot of row

Women’s nomad

A multirow Brown

A multirow is a threepart

Orlyak ordinary

Osmund (clean)

The ostrich is ordinary

Telipteris swamp

Male shield

Austrian shield

Heldow is sensitive

Hills of fern plants

The most significant variety of ferns can be found in cheese and warm climate in tropics and subtropics, but in general these plants can occur in almost any climatic belt.

These plants can be found from the polar circle to the jungle area at the equator, and it is here that these representatives feel most freely. For example, on Jamaica there are almost five hundred species of fernlike ones and with advancement to the north, their number gradually changes towards reducing.

Propagation of fern plants

All fervorshaped are spore plants that multiply with the help of sporangis, organs located on the lower side of the sheet and the dispute intended for ripening. After ripening, spores are spilled out and under favorable conditions turn into an embryo, t.e. small sheet no more than 3 cm. Under normal conditions, he can live up to a couple of months, but is quite capable of existing until 15 years.

Foldshaped can multiply in several ways:

Small plants are formed from small kidneys, which take the roots, disconnected from the sheet, and then strengthened in the ground, turning into a fullfledged plant.

They join with long legs to the central vein of the sheet and are covered with a protective bedspread on top, similar to the kidney. At the time of ripening, the dispute breaks through and disputes are outside. Then they form the embryo, a small plate, and then pass the entire cycle before the formation of the plant.

Subsequently, gametes merge and form zygotes from which embryos are formed, already possessing the rudiments of all fern organs. At first, it grows due to the embryo, and therefore already forms a young plant.