Kukushkin flax, or polytrichum, is a moss that prefers areas with excess moisture. This type of moss develops in well-lit wetlands. In our country, it is most often found in the north or in the center.

Structure

The dark green stem can grow from 5 to 50 cm in height. Its leaves are linear-subulate, do not have petioles and are pointed. At the bottom of the stem are rhizoids - this is a formation in the form of threads. They attach to the substrate and conduct micronutrients into the moss cells.

Source: Depositphotos

Inside the stem is a conducting system that delivers water and dissolved nutrients to all plant cells.

The main stem grows perpendicular to the ground and lacks leaves. The secondary stem is branched and has leaves. Those leaves that are next to the rhizoids develop in the form of scales.

The leaves of the plant are straight. When dry, they adhere to the stem, and when wet, they bend away from it. Also on the upper surface of the leaves there are vertical, longitudinal plates, due to which the area for the photosynthesis process increases. You can see these plates if you cut the sheet across. The most interesting thing is that the shape of the cell at the top is different for all species.

Elongated plant cells form pairs and perform the function of transporting fluid and carrying out photosynthesis.

Kukushkin flax can be used for completely different purposes:

• It can be used as interventional insulation due to its dense structure;
• Also, the plant is dried and stuffed with mattresses or pillows;
• It is used in medicine, because it has elements that have diuretic, disinfecting and anti-inflammatory properties.

Varieties of polytrichum

Ordinary. If the conditions for its growth are favorable, then it can reach a length of half a meter. It is because of this that it is considered one of the longest mosses on Earth. Its leaves are serrated and have a large base. Because of this, it seems that they are strongly spaced along the stem. Also, this species grows on all continents except Antarctica, but in the tropics it is found only in the mountains. The plant prefers moist soils, lowlands, swamps and coniferous forests. It forms thick and dense sods that accumulate moisture. It turns out that the already moist soil becomes even wetter. Ultimately, this leads to the appearance of a swamp and peat formation.

Juniperus. Moss of this species reaches 10-15 cm in length. Its leaves have a smooth rolled edge and a short base. It also grows on all continents, but it prefers the taiga zones. He also likes open areas without excess moisture. For example, a wasteland or a forest after cutting down. And when no one interferes with him, he literally covers the carpet.

Piliferous. Length 3–5 cm. Its leaves are closed by a long white hair. It grows in the same way throughout the planet, but loves well-lit sandy soils without excess moisture.

Compressed. The length of the plant is not more than 20 cm. It differs from all other species precisely in its leaves: they are short, look up and they are all almost the same size. Only the upper part of the stem has leaves, and on the lower part there is a dense cover - rhizoids, which are part of the root system.

Source: Depositphotos

Polytrichum is an aggressive plant. If the entire forest is cut down, or it burns down, then the moss will very quickly take over the entire free territory.

reproduction

Moss can reproduce in two ways: asexual and sexual.

After the plant has faded, spores are formed in boxes - sporangia, with which the plant reproduces. The spores are very small and light, so that even a small wind can blow them apart. Mature spores are transferred to the substrate. If the climate is favorable, then they form threads consisting of many cells. Further, gametophytes appear from them with the help of budding - brown-green perennial shoots with rhizoids. They already independently develop and become adults and independent organisms.

Polytrichum is a dioecious plant that has both male and female shoots. At the end of the male stems in the center of the leaf rosette, antheridia are formed, which contain gametes, in other words, spermatozoa. On the female shoots, archegonia with mature eggs are formed.

fertilization process:

1. When there is a period of prolonged rainfall or floods, the spermatozoa are separated from the antheridium and attached to the egg. They unite, resulting in the formation of a zygote - a fertilized cell.
2. After 11–13 months, a box is formed from the zygote, it is also called sporogon, it is located on a long bare stem. Spores begin to develop in it, which are carried by the wind to a distance of 2–5 m. Then the spores germinate into a thread - a pregrowth, from which buds begin to form, which will eventually become female and male plants.

Reproduction of cuckoo flax is an alternation of sexual and asexual reproduction methods.

Moss can also be propagated vegetatively. To do this, place a layer of substrate with moss in a moist nutrient medium, and it will grow into a dense dense cushion-like turf.

Kukushkin flax is a genus of mosses. Usually, when considering the structure of cuckoo flax, one of its species (common cuckoo flax), which are widespread in Russia, is considered. This plant grows in places with high humidity, needs good lighting. Kukushkin flax forms a dense cover on the ground, which prevents the growth of other plants and the evaporation of moisture. As a result, it can lead to waterlogging of the soil.

By appearance Cuckoo flax is a herbaceous plant about 20 cm high. The stem usually does not branch, has a greenish-brown hue. On the stem are many narrowed thin leaves. You can see the vein on them. Cuckoo flax is attached to the soil with the help of rhizoids (similar to roots, since they do not have tissues characteristic of roots).
Kukushkin flax ordinary

The stem serves to support and transport substances. Cuckoo flax has primitive conductive tissues. Thus, water with minerals flows through some cells, organic substances through others.

The leaves contain rows of cells whose main function is photosynthesis, that is, the synthesis of organic substances. However, apparently the leaves can also absorb water.
Rhizoids not only attach the plant to the soil, but also absorb water with minerals dissolved in it.

Kukushkin flax reproduces by spores. When the spore falls on moist soil, it germinates, forming a so-called seedling. It looks like a branching thread. Buds are formed on the seedling, from which cuckoo flax plants grow.

Kukushkin flax is a dioecious plant. This means that he has male and female plants. At the top of the stems of male plants, the so-called antheridia are formed. They produce spermatozoa. Archegonia are formed on female plants. An ovum matures in each archegonium.

During rains or floods, spermatozoa swim up to the eggs. Fertilization and zygote formation occur. Water plays an important role in the life of mosses. This is the only way sexual reproduction is possible. Thus, in evolutionary development mosses, not only in structure, are not very far removed from algae, but also in their way of life.

Spores mature in the sporophyte capsule. When the cap falls off, the spores disperse. Once in favorable conditions, they give rise to a new seedling.

1. General characteristics of green mosses.

In the life cycle of green mosses, as in all bryophytes, the haploid generation predominates - the gametophyte, the sporophyte in the form of a box, develops on the gametophyte. The largest genus of green mosses is cuckoo flax. Mosses of this genus are perennial plants. Usually they grow in swampy forests and along the outskirts of marshes, forming dense, dense sods.

2. External structure moss cuckoo flax.

The stem of the cuckoo flax is erect, usually non-branched (30-40 cm), the leaves are linear-subulate. The leaf has a median vein. Cuckoo flax has no roots. They are replaced by filamentous outgrowths - multicellular rhizoids, which are located on the lower part of the stem. They suck up water from the soil, and also serve to attach.

3. Reproduction and development of moss cuckoo flax.

Kukushkin flax is a dioecious plant. Female reproductive organs (archegonia) and male reproductive organs (ante-ridia) develop on different plants. Eggs are produced in archegonia and spermatozoa are produced in antridia. Male plants can always be distinguished by the presence of larger yellow-brown leaves that surround the male genital organs - antheridia. There are no such leaves on female specimens. After the eggs are fertilized by spermatozoa, which enter the female genital organs through drops of water, a sporophyte is formed from the zygote - a box on a long stalk (it contributes to the spread of spores over a greater distance). The box consists of an urn and a lid, 38 covered with a cap on top. In the urn there is a sporangium with spores. When the spores are ripe, in dry weather, the cap, and then the cap, fall off. A thin leg sways even from a weak breath of wind, and small and light spores get enough sleep. material from the site

Development cycle: spores (haploid; when they are formed, reduction division occurs) -> spore germination in moist soil -> filamentous pregrowth (proto-nema) -> buds are formed on the protonema, and from them leaf-stem plants (haploid gametophytes) .

4. Origin of the name "cuckoo flax".

The slender brown stalks of cuckoo flax are dotted with small dark green leaves and look a bit like a smaller flax plant. Hence the last part of the name - linen. The pods that appear on female plants are similar to sitting on a pole cuckoo.

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Kukushkin flax belongs to mossy plants of the green moss family. On the this moment There are more than 100 varieties of this plant family, which are distributed throughout the globe. Most often, cuckoo flax can be seen in our forests, swamps, mountains, tundra, and also in the northern part of the country. In addition, certain species of this plant family are actively involved in waterlogging, as well as peat formation of the soil.

In our country, as well as other CIS countries, the cultivation of cuckoo flax became known several centuries ago. Already today, about 10 varieties of cuckoo flax grow on the territory of our state. The largest number of this plant is concentrated in the forests of the northern and central parts. The most common among this family of green mosses is considered to be common cuckoo flax, or, as it is also called by the people, common polytrichum. It is these plants that are represented by forests in the taiga, swamps and other types of northern circles.

Growing cuckoo flax
The cultivation of cuckoo flax began in ancient times, when they began to insulate their houses and roofs with bast plant species. And even despite the fact that cuckoo flax is not a direct relative of the bast family (flax, jute, hemp), nevertheless, it has good hygroscopic properties, due to which coatings from such a plant can perfectly not only absorb moisture, but also give her at the right time. It was thanks to the cuckoo flax in the old buildings of those times that not only the ventilation of the grooves was provided, but also the destruction of the house itself was prevented.

Speaking about the structure of this plant, first of all, I would like to note that cuckoo flax belongs to the perennial leaf-stemmed family of green mosses. As a rule, growing cuckoo flax at home allows you to get a fairly large plant with pronounced rhizoids at the bottom of the stems. The primary stem of cuckoo flax develops without leaves under normal conditions, but the secondary stem can be either simple or branched. The average length of the secondary stem, as a rule, reaches 30-40 cm. All the stems along their entire length are densely covered with leaves, which have assimilation plates in the upper part. Leaves that are located at the bottom of the stem are presented in the form of scales.

The inner part of the stem is represented both by a primitive conducting system, which ensures the movement of water and other useful substances along the plant stem, and by individual cells that perform the function of transporting water.
Cuckoo flax reproduces both asexually and sexually. As for the asexual reproduction process, it can be noted here that the gametophyte of a plant is a special kind of green shoot with leaves. As a result, the plant forms many spores, from which, under normal conditions of growing cuckoo flax, an shoot in the form of a box (sporangia) develops. The structure of this box differs from similar spore boxes of other plants of this family, since in the upper part it is closed with a cap and resembles a linen buckle in appearance. The box itself resembles a cuckoo. This is what determines the name of this plant - cuckoo flax.

With the modern pace of life, the constant pollution of the external environment, as well as the terrifying state of the environment, growing flax is simply necessary. Initially, this is due to the fact that it leads to the accumulation of moisture, and also contributes to the formation of peat.

Kukushkin flax is a plant that is on the territory Russian Federation most common in the forests of the northern and middle belt. Favorable conditions for it are observed in the taiga swampy long-moss forests, in swamps and in wet meadows. The plant belongs to the genus of leaf-stemmed mosses, more than a hundred of its varieties are found on the planet. Kukushkin flax, which forms cushion-like tufts, is often found in the tundra and in highlands. The most widespread in the territory of the CIS countries was ordinary polytrichum (the second name of the plant).

The importance of the sun

Kukushkin flax loves light very much. That is why in dark spruce forests, even if the soil there is damp and fertile, it will be limited in growth and development. With a sufficient amount of sunlight, the plant rapidly stretches, actively capturing new areas and covering the soil with a dense carpet. The ground under cuckoo flax dries out much more slowly, which is why its growth gradually leads to waterlogging of the area.

Description

Cuckoo flax moss is distinguished by rather tall stems (their length is 10-15 centimeters, however, forty-centimeter plants are also found). The conductive system ensures the movement of water and nutrients along the stem.

origin of name

The described plant has straight brownish stems. On them are small leaves of a dark green hue, which resemble flax in miniature. But the boxes that appear on female plants evoke associations with the cuckoo, located on a kind of pole.

The structure of the cuckoo flax

The plant in question is classified as a leafy perennial moss. Its dimensions are large, in the lower part of the stem there are rhizoids - primitive analogues of roots. There are no leaves on the primary horizontal stem. The secondary stem can be either simple or branched. It is erect, the average length is within fifteen centimeters. Each leaf has a main large vein. Kukushkin flax, whose structure is quite simple, has scaly lower leaves.

stem functions

The main role of this part of the plant is supporting. Equally important is the conductive capacity of the stem. It acts as a link between the leaves and the root system. The stem also performs some secondary functions. Among them is the preservation of the supply of nutrients.

Reproduction and development

The plant reproduces in the following ways: sexual (gametes) and asexual (spores, shoots). They alternate.

How exactly does the cuckoo flax plant reproduce? The spores that the plant produces are in a sporangium (box) on a stem. After maturation, they spill out of this natural storage. Under favorable conditions, spores form a multicellular thread, and from it, in turn, several gametophytes appear (this happens by budding). A gametophyte is a green perennial shoot that has leaflets and rhizoids (root-like formations). The latter take salt and iodine from the soil. Leaf cells provide the synthesis of all other necessary substances. Based on this, it can be argued that the gametophyte is an independent organism.

After a while, the gametophyte stops growing. Then the cuckoo flax starts breeding. In the center of the rosette of leaves (location - at the top of the stem), male and female genital organs develop. The first are represented by antheridia (the name comes from the Greek word "anteros", which means "blooming"), in which mobile gametes - spermatozoa - pass the development cycle, as well as archegonia - female genital organs that are responsible for the formation of a motionless female gamete - egg.

Male plants are characterized by the presence of larger leaves, painted in female specimens do not have such leaves.

With the onset of a rainy period or floods, spermatozoa (male cells) get the opportunity to swim up to the egg. As a result, they merge. At the end of the fertilization process, a zygote appears (this word comes from the Greek "zygotos", which translates as "connected"). This is the first stage in the development of the embryo. The next year, from the fertilized zygote, a box (sporogon) develops, located on a fairly leafless. In the future, the box becomes a place for the development of spores. This natural storage is very fragile. It sways even in the slightest breeze. After the cap falls off and the spores fall out, the germination of a green branched thread - a pregrowth - is observed. Note that for a successful result, it is necessary that the spores fall into a favorable environment for them, in which case the cuckoo flax will multiply.

On the pregrowth, buds are formed, from which female and male specimens of the plant appear. Thus, it can be seen that the life cycle of moss development includes a successive alternation of asexual and sexual generations. In the course of evolution, this feature has developed in many plants, including cuckoo flax.

Propagation of this vegetatively makes it easy to get a thick green carpet in the backyard. It is enough just to place a small piece of moss on a damp area. However, the ability of this plant to swamp its habitat should be taken into account.

Use for various purposes

If you remove the leaves from the cuckoo flax, you can get flexible rigid threads formed by the central stems. Our ancestors used this natural material to make brushes and brooms. After soaking and combing, the stems become an excellent basis for mats, rugs, baskets and blackout curtains. It is noteworthy that during the excavations of an early Roman fort in England, the remains of baskets created from cuckoo flax were found. Products date back to 86 AD.

Previously, cuckoo flax was widely used in the manufacture of raincoats for warriors and travelers. The resulting garments were particularly durable. In addition, they had decorative value.

Healers advise using this type of moss to enhance work digestive system, elimination of gastric colic and dissolution of stones in the kidneys and gallbladder.

Kukushkin flax, the structure of which allows it to be used in gardening for decorative purposes, has a positive effect on the soil. So, this plant is able to normalize soil acidity in a maximum of two seasons. After that, any garden plants can be successfully grown on the restored soil. The dead parts of the moss will serve as an excellent fertilizer.

Most unusual option the use of cuckoo flax - as malt in the manufacture of whiskey.

natural insulation

Kukushkin flax is able to effectively protect the structure from the penetration of cold and moisture. The fact that the moss does not rot is greatly appreciated. Its placement between the logs of the log house makes it possible to ensure that moss is used fresh for this purpose. Before laying natural insulation, it must be thoroughly cleaned of twigs, sticks, cones, grass and other inclusions.

moss sphagnum

This plant belongs to the genus of white (peat) mosses. 320 species have been identified. Sphagnum is predominantly represented by bog mosses, which form dense aggregations that form either large cushions or thick carpets on sphagnum bogs. But in moist forests sphagnum is much less common. Kukushkin flax resembles this plant with its erect stem, reaching ten to twenty centimeters in height. Sphagnum leaves are single-layered, placed on bundled branches. The leaves contain many aquifers with pores that actively absorb water. This fact causes a large moisture capacity of the plant. In areas where these mosses appear, raised bogs quickly develop.

Annually, the stems die off at the bottom of the plant. They form peat. Further growth of the stem is provided by the apical branches.

Note that sphagnums play an important role in the formation and existence of swamps. As mentioned above, dead patches of moss form peat deposits. Peat formation is possible due to stagnant waterlogging, the provision of an acidic environment by mosses and the lack of oxygen. Under these conditions, the processes of decay do not occur, the sphagnum does not decompose. Peat is a valuable product from which wax, ammonia, paraffin, alcohol, etc. are obtained. It is widely used in medical practice and in construction. Moss acts as a biofuel and an effective fertilizer.

What is useful sphagnum?

Many recipes of traditional and official medicine include this component. And all because sphagnum moss is an excellent antiseptic and reliable. It helps to heal festering wounds due to its ability to absorb large amounts of moisture. According to this indicator, sphagnum surpasses the best varieties of hygroscopic cotton wool. This moss is able to produce a bactericidal effect due to the presence of sphagnol - a special phenol-like substance that inhibits the development and vital activity of Escherichia coli, Vibrio cholerae, Staphylococcus aureus, Salmonella and some other pathogenic microorganisms.

Flower growers actively use sphagnum to grow houseplants. It is a component of the substrate, a mulch layer or performs drainage functions. Moss is not rich in nutrients, but it gives the soil the required looseness. The excellent hygroscopicity of sphagnum explains its ability to evenly distribute moisture. The presence of sphagnol determines the bactericidal properties of the described species of moss, which allows you to effectively care for the roots of the main plant, preventing the development of diseases and decay.

Kukushkin flax, or polytrichum, is a plant from the species of mosses. It occurs in wet meadows, swamps, in the forests of central and northern Russia. If you look closely, its stems covered with thick green leaves resemble tiny flax sprouts. It is used as an interventional insulation in wooden houses.

Description of the plant cuckoo flax

Polytrichum usually grows up to 10-15 cm in height. But if the conditions suit him, then he can stretch up to 40 cm. For this, moist soils of spruce forests and swampy plains are needed. There is room for moss here, and it stretches upwards, because, like other plants, it loves the sun. It aggressively captures more humid places, covering the ground with a pillow, where it will be difficult for another species to germinate. This plant especially loves forest clearings and conflagrations. Densely spreading in the forest, it swamps areas and interferes with the restoration of forests.

Kukushkin flax grows in wet, wetlands

In the people, this flax is called "iron ore" for its strength and "red moss" for the color of the stems. It has been performing its function of insulating houses flawlessly for more than a dozen years.

In its structure, it is a stalk with primitive root rudiments - rhizoids, through which the plant absorbs water and mineral salts. It can also absorb water in other parts of itself. The lower leaves of the plant are like scales. The rest of the leaves are narrow, with denticles at the ends. Photosynthesis takes place in them - the conversion of light energy into chemical vital energy.

Life cycle and reproduction of cuckoo flax

This type of plant is dioecious. This means that female and male germ cells develop on different plants. In male plants, the upper leaves are brownish in color. Here, male gametes are formed - spermatozoa. In female plants, all leaves are the same. At the same time, at the top of the plant are female gametes - eggs.

Fertilization requires water. Only during rains or heavy dew do spermatozoa move to female gametes, and a fusion of the feminine and masculine occurs. A zygote is formed - a cell with a double set of chromosomes, capable of starting a new generation.

Populating new areas with disturbed soil composition - conflagrations, for example, mosses accumulate moisture. After dying, they give rise to the formation of new soil

From the zygote, a new sporophyte plant appears with sporangium - a box with a lid in which spores ripen. When they ripen, the lid opens, the spores spill out. Once in moist soil, the spore germinates and buds. New leafy plants emerge from them.

Despite the emergence of modern materials for insulation, this type of moss has not lost its relevance and perfectly performs the function of keeping warm and insulating. Mosses are of great importance in the formation of peat and new soils.

In order to occupy new spaces, ancient plants had to adapt to completely new living conditions. For example, the constant loss of moisture through evaporation contributed to the appearance of a protective wax layer. The lack of support in the air, in contrast to water, caused the formation of a fairly rigid body, the principle of gas exchange has changed. The temperature and biochemical conditions became completely different, and the plants successfully adapted to them. Consider in this article the life cycle of mosses.

What is moss?

Mosses are a group of ancient organisms. According to some assumptions, they are the ancestors of the currently existing land plants. Water on our planet is the source of life, in which all living things, including plants, originated. About 420 million years ago, the descendants of green algae began to explore the land.

Such adaptation mechanisms can be traced most clearly in mosses. For example, the main condition for success is the availability of water. Mosses can also reproduce only with the help of moisture.

Life cycle moss is very interesting. Of the entire group, they are the most primitive organisms. Bryophyta or bryophytes are multicellular plants that are practically devoid of conductive tissue. Therefore, the sizes of these living organisms are quite small - from 1 mm to 50 cm. Mosses do not have roots, they are attached to the surface of the earth with filamentous outgrowths, rhizoids, with which these plants absorb water. Rhizoids sometimes consist of a single cell. Unlike the roots of all other plants that have multicellular conductive tissue. Other parts of the moss body can be loosely defined as the stem and leaves. However, in fact, they are completely different from the stems and leaves of all other plants on the planet in their structure.

Where do they meet?

Mosses have successfully adapted to life in a variety of temperature and climatic conditions and are distributed almost throughout the planet: from the polar regions to the tropics. They perfectly exist in conditions of high humidity - in forests, mountains. Mosses are also found in arid regions. The survival rate of bryophytes is amazing - they can withstand exposure to very high temperatures, up to 70 degrees Celsius. In a dry climate, mosses have adapted to fall into a state of suspended animation associated with seasonal climatic fluctuations. When the rains fall and the air temperature drops, the soil is moistened, and the moss "comes to life", the breeding cycle begins. Consider the importance of spores in the life cycle of mosses.

Moss living conditions

Moss thrives in places with little sunlight, such as caves, cracks and crevices in rock, occupying those ecological niches where other plants cannot exist.

The only place where mosses are not able to exist is in saline soils near the sea.

Moss spores are unusually tenacious. With the wind, they can travel great distances. Spores remain viable for decades.

Mosses accumulate significant reserves of moisture, therefore, with their help, a particular landscape is regulated. Therefore, moss is extremely important for the ecosystem. In addition, for some species of animals, moss is the main food supply.

About 30 thousand species of mosses grow on the earth today. Scientists classify these plants according to their morphology, the structure of the spore boxes, and how the spores are dispersed.

Mosses can reproduce both by spores and vegetatively. In the life cycle of moss, the sexual generation predominates over the asexual one.

Deciduous mosses or bryopsids

This is a rather numerous class of plants, which is represented by 15 thousand species of mosses. They are extremely diverse in appearance, size and shape. This plant is a stem covered with leaves that spiral around the stem. The very stage of their development is called the gametophyte. The mode of reproduction of deciduous mosses is spores. Most often, these plants are found in wet places, in swamps, as well as in the tundra. Kukushkin flax and sphagnum are typical representatives of briopsids.

liver mosses

Liverworts are represented by two subclasses: Jungermannian and Marchantian. These plants are also numerous - 8.5 thousand species. Just like in deciduous mosses, the gametophyte is the stage of their greatest viability. The plant itself is a thick stem with leaves that are arranged along the stem. The method of reproduction is spores that spread with the help of a special device, a kind of "spring", which is called elatera. These plants are well established in humid tropical and temperate climates. Among the representatives are polymorphic marchantia, ciliated ptilidium, hairy blepharostroma, and others.

Anthocerotus mosses

This class is not so numerous and is represented by 300 plant species. The sporophyte is the most important life stage in the life cycle of this plant. Anthocerotus mosses look like a thallus - this is a body that is not divided into root, stem and leaves. These mosses grow in damp tropical forests and temperate zones. Anthoceros is a typical representative of this class.

The life cycle of the cuckoo flax will be described below. Moss cuckoo flax is a perennial plant. Its structure is a fairly developed structure. The primary horizontal stem is brown without leaves and the secondary stem is upright, branched or solitary.

The secondary stem is covered with dark green, harsh, awl-like leaves. These stems can reach a height of 10-15 to 40 cm. The lower leaves are scales. The plant has a primitive conducting system that is able to move water and minerals along the stem to the leaves. Its rhizoids are capable of reaching a length of almost 40 cm.

Places of growth of moss cuckoo flax

Kukushkin flax usually grows well in damp places, in swamps, damp meadows and spruce forests, loves sunlight. In open areas it grows very powerfully, capturing more and more new territories. Its stems “envelop” the soil so tightly that the seeds of other plants are not able to germinate. This plant takes a fancy to clearings in forests or conflagrations. This moss absorbs water extremely well. Plant density retains moisture in the soil. As a result, the area becomes swampy.

People have long used this plant as a heater. Caulk with it the walls of log houses. Sometimes used as a medicinal plant for colds.

Kukushkin flax is involved in the formation of peat. This is a valuable fertilizer, a good raw material for the chemical industry.

Life cycle of moss cuckoo flax

Moss cuckoo flax is a dioecious plant. This is a phenomenon when different-sex organs are formed on separate stems of one plant - female and male.

Kukushkin flax develops by alternating two generations - asexual and sexual. The sporophyte is the life cycle of mosses that results in the formation of asexual cells. They contain Gametophyte - another life cycle of the same plant, which ends with the formation of gametes, germ cells containing only one set of chromosomes - haploid.

Now it is clear why the sexual generation prevails over the asexual one in the life cycle of mosses.

Spore boxes are popularly believed to look like a cuckoo sitting on a pole. In general, outwardly, the cuckoo flax moss resembles a miniature one, from where it got its name. The thin hairs on the cap covering the spore box are also similar to linen yarn.

The box itself consists of several parts - an urn, a neck and a lid. Inside it is a small column. It just contains sterile cells, from which, as a result of reduction division, haploid spores ripen. The urn ends with a ring. After the ripening process is completed, this ring, under the breath of the wind, easily separates the urn and the lid from the stem. The spores fall to the ground and the important life cycle of the plant begins again.

Moss life cycle stages

Asexual spores in the process of "maturation" become haploid spores (containing half the set of chromosomes) as a result of indirect, reductional division.

When a haploid spore falls on moist soil, it begins to germinate, forming a protonema - a filamentous pregrowth. From it the gametophyte is formed - female or male.

On the tops of different gametophyte stalks of cuckoo flax, antheridia and archegonia develop - male and female genital organs. In the archegonium, eggs mature, and in the antheridium, biflagellated spermatozoa. Externally, male plants are distinguished by large yellowish-brown leaves at the top. In female plants, such leaves are absent.

Successful fertilization requires moisture droplets that carry sperm from the antheridium to the archegonium, where the eggs are located. This process is usually facilitated by rain or heavy dew.

As a result of the fusion of sperm and egg, a diploid zygote is formed at the top of the female plant. From it grows a new generation of this plant, sporophyte or sporogon. And it is a sporangium box in which spores ripen.

We have considered the sequence of stages of the moss life cycle.

The structure of the moss cuckoo flax

The body of mosses is similar in structure to algae, since it also consists of a thallus. However, it may have a structure resembling stems and leaves. It is attached to the soil with the help of rhizoids. These plants are able to absorb water and minerals not only directly by rhizoids, but also by the whole body.

The value of moss in nature

In general, mosses are the most important component of the ecological system of our planet. The life cycle of mosses is different from that of other higher plants. They do well in nutrient-poor soils. They inhabit those places that have undergone adverse anthropogenic impacts. Thus preparing the earth for restoration. After all, dying, moss forms a useful soil substrate, on which other plants will subsequently grow.

Mosses are indicators of environmental pollution, in particular, the atmosphere. Since some types of mosses do not grow in places where the concentration of sulfur dioxide is exceeded in the air. The absence of certain types of mosses in traditional habitats can also be used to judge atmospheric pollution. However, mosses also indicate changes in soils, and much more.

Mosses protect the delicate balance in permafrost areas, covering the soil from the sun's rays. thus maintaining the ecological balance.

Now, if you are asked: "Characterize the life cycle of moss", then you can easily do this.

All processes in living organisms occur, repeating in time. The life cycle is called the totality of all phases, starting with the formation of a zygote, giving rise to a new organism and ending with the maturity phase, in which this organism is able to give rise to a new generation. Each living being is first born (from a zygote), then grows, matures, and at a certain time begins to reproduce, when it gives rise to a new generation that goes through the same stages (phases) of development. This is cyclicity (repetition of stages of life). The development cycle is usually closed.

The concept of the life cycle of plants

In the life cycle of plants, there is an alternation of asexual and sexual reproduction and the alternation of generations associated with this.

A haploid (n) plant organism that produces gametes is called a gametophyte (n). He represents the gender generation. Gametes are formed in the genital organs by mitosis: spermatozoa (n) - in antheridia (n), eggs (n) - in archegonia (n).

Gametophytes are bisexual (antheridia and archegonia develop on it) and dioecious (antheridia and archegonia develop on different plants).

After the fusion of gametes (n), a zygote with a diploid set of chromosomes (2n) is formed, and an asexual generation develops from it by mitosis - a sporophyte (2n). In special organs - sporangia (2n) of the sporophyte (2n), after meiosis, haploid spores (n) are formed, during the division of which new gametophytes (n) develop by mitosis.

In the life cycle of green algae, the gametophyte (n) predominates, that is, the cells of their thallus are haploid (n). At the onset of favorable conditions(cooling, drying up of the reservoir) sexual reproduction occurs - gametes (n) are formed, which merge in pairs into a zygote (2n). The zygote (2n), covered with a shell, hibernates, after which, when favorable conditions occur, it divides by meiosis with the formation of haploid spores (n), from which new individuals (n) develop.

Life cycle of mosses (cuckoo flax)

In mosses, the sexual generation (n) predominates in the development cycle. Leafy moss plants are dioecious gametophytes (n). Antheridia (n) with spermatozoa (n) are formed on male plants (n), archegonia (n) with eggs (n) are formed on female plants (n). With the help of water (during rain), spermatozoa (n) get to the eggs (n), fertilization occurs, a zygote (2n) appears. The zygote is located on the female gametophyte (n), it divides by mitosis and develops a sporophyte (2n) - a box on a leg. Thus, the sporophyte (2n) in mosses lives off the female gametophyte (n).

In the sporophyte box (2n), spores (n) are formed by meiosis. Mosses are heterospore plants, distinguish between microspores - male and macrospores - female. From spores (n), by mitosis, first pre-germs develop, and then adult plants (n).

Life cycle of ferns

In ferns (also horsetails, club mosses) the sporophyte (2n) predominates in the life cycle. On the underside of the leaves of the plant (2n), sporangia (2n) develop, in which spores (n) are formed by meiosis. From a spore (n) that has fallen into moist soil, a growth (n) germinates - a bisexual gametophyte. Antheridia (n) and archegonia (n) develop on its lower side, and spermatozoa (n) and eggs (n) are formed in them by mitosis. With drops of dew or rainwater, spermatozoa (n) get to the eggs (n), a zygote (2n) is formed, and from it - the embryo of a new plant (2n).

On the scales of female cones there are ovules - megasporangia (2n), in which 4 megaspores (n) are formed by meiosis, 3 of them die, and from the rest a female gametophyte develops - endosperm (n) with two archegonia (n). In archegonia, 2 eggs (n) are formed, one dies.

On the scales of male cones there are pollen sacs - microsporangia (2n), in which microspores (n) are formed by meiosis, from which male gametophytes develop - pollen grains (n), consisting of two haploid cells (vegetative and generative) and two air chambers.

Pollen grains (n) (pollen) are carried by wind to female cones, where by mitosis from the generative cell (n) 2 sperm cells (n) are formed, and from the vegetative cell (n) - a pollen tube (n), which grows inside the ovule and delivers sperm cells (n ) to the egg (n). One sperm dies, and the second participates in fertilization, a zygote (2n) is formed, from which a plant embryo (2n) is formed by mitosis.

As a result, a seed is formed from the ovule, covered with a peel and containing an embryo (2n) and an endosperm (n) inside.

Life cycle of angiosperms

Angiosperms are sporophytes (2n). The organ of their sexual reproduction is a flower.

In the ovary of the pistils of the flower there are ovules - megasporangia (2n), where meiosis occurs, and 4 megaspores (n) are formed. 3 of them die, and from the rest, a female gametophyte develops - an embryo sac of 8 cells (n). One of them is an egg (n), and two merge into one - a large (central) cell with a diploid set of chromosomes (2n).

In microsporangia (2n) of stamen anthers, microspores (n) are formed by meiosis, from which male gametophytes develop - pollen grains (n), consisting of two haploid cells (vegetative and generative).

After pollination, 2 sperm cells (n) are formed from the generative cell (n), and from the vegetative cell (n), a pollen tube (n) grows inside the ovule and delivers the sperm cells (n) to the egg cell (n) and the central cell (2n). One sperm (n) merges with the egg (n) and a zygote (2n) is formed, from which the plant embryo (2n) is formed by mitosis. The second sperm (n) fuses with the central cell (2n) to form a triploid endosperm (3n). Such fertilization in angiosperms is called double fertilization.

As a result, a seed is formed from the ovule, covered with a peel and containing an embryo (2n) and an endosperm (3n) inside.

Homework 1

1. Learn the abstract.

2. Solve biological problems (2 to choose from).

Task 1. What set of chromosomes is typical for the cells of the ulotrix thallus and for its gametes? Explain from which initial cells and as a result of what division they are formed.

Task 2. What set of chromosomes is typical for the zygote and spores of green algae? Explain from what initial cells and how they are formed.

Task 3. What chromosome set is typical for gametes and spores of cuckoo flax? Explain from which initial cells and as a result of what division they are formed.

Task 4. What chromosome set is typical for the cells of the leaves and the pod on the leg of the cuckoo flax? Explain from which initial cells and as a result of what division they are formed.

Task 5. What chromosome set is typical for leaves (wai) and fern growth? Explain from what initial cells and as a result of what division these cells are formed.

Task 6. What chromosome set is typical for pine pollen grain and sperm cells? Explain from what initial cells and as a result of what division these cells are formed.

Task 7. What chromosome set is typical for pine megaspore and endosperm cells? Explain from what initial cells and as a result of what division these cells are formed.

Task 8. What chromosome set is typical for the microspore, which is formed in the anther, and the endosperm cells of the flowering plant seed? Explain from what initial cells and how they are formed.

Animal life cycle

Animals also live in cycles. The birth of a living organism begins with a zygote - a fertilized egg.

The development of animals can be direct (without transformation) and indirect (with transformation).

Indirect (larval) development. Consider the life cycle of a cabbage butterfly, which consists of several phases and begins with an egg - they can often be found on cabbage from the underside of the leaf. After a few days, small caterpillar larvae come out of them, which are not at all like adult butterflies. They have chewing mouthparts, feed on leaves, grow rapidly, molt and then turn into pupae - motionless, not feeding on anything. At this stage, they hibernate, and in the spring adult insects are formed from pupae - butterflies: males and females. Fertilization occurs, and the female lays her eggs on cabbage leaves. Development with complete transformation makes it possible for insects to better survive in nature, since their larvae feed on different foods, often live in a different environment than adults. Different nutrition of larvae and adults excludes competition between them, allows these animals to use the food conditions of the habitat more widely. In addition, insects with complete metamorphosis can endure unfavorable environmental conditions in any one of the four developmental phases.

1 - eggs; 2 - caterpillar on a damaged cabbage leaf; 3 - pupa; 4 - butterfly (imago).

Direct (intrauterine) development.

The life cycles of living organisms are associated with cyclic natural phenomena, such as seasonality - the change of seasons. Even if the development of the embryo goes in utero (as it happens in most mammals). Mammals are dioecious animals. The maturation of germ cells occurs, as a rule, in early spring, with the awakening of all natural processes. In animals, the time of reproduction begins, associated with the formation of germ cells and hormones, then the period of pair formation begins. This is followed by internal fertilization, building or choosing a place for rearing offspring: a nest, a den, any shelter if the offspring are born blind and unable to follow their parents. Mammals have a developed instinct for caring for offspring. Females feed the cubs, warm them with the warmth of their bodies, protect them from enemies, and teach them how to find food. Sometimes males also take part in this. The offspring grows up and after a while becomes sexually mature.

Homework

1. Learn the abstract.

2. Answer the question.

What is the biological meaning of the larval stage?