It is a lichen. Scale lichens: description, structure, meaning in nature
Nature is rich and extremely diverse, as you can see by visiting various corners our vast country or by ordering tours to other states. A special group of plants looks curious, which differs from those plants that we are used to seeing daily - lichens. This is at the same time a common species, and at the same time its representatives cannot be called ubiquitous. So, let's figure out where lichens grow.
Where does lichen grow?
Lichens are a group of living organisms that are an association of fungi with algae that live as a single organism. In nature, there are at least 26 thousand of their species, among which the following are distinguished:
- epilithic, growing on rocky surfaces;
- epigean, their habitat is soil (such as);
- epiphytic, covering tree trunks.
At the same time, lichens can be found everywhere in the wild - they grow on every continent, not excluding Antarctica. Surprisingly, even in the barren lands of the Arctic expanses, this unique species is found. This is exactly the place where black lichens grow. There low temperatures, there is practically no water, but such a dark color helps the body quickly absorb the secreted in a low amount solar radiation. Well, black lichen takes water from snow melting in the sun. For a long time, lichens remained a mystery to scientists. To tell the truth, so far scientific world there is no single point of view that there is a lichen - a representative of the kingdom of fungi or the kingdom of plants.
The habitat zone where fruticose lichens grow is, first of all, bare rocks, trees and soil. Moreover, the lichen feels great in the harsh conditions of the North, in the taiga, highlands, and in the middle of hot areas. tropical countries. Being an unpretentious culture, lichen settles high in the mountains and on poor lands. At the same time, lichens, destroying over time upper layer rocky soil, when dying, they leave a humus layer, on which other plants later develop. By the way, lichens grow extremely slowly, for example, the growth of reindeer moss is only 2-3 mm per year.
At the same time, it is impossible to confidently call large settlements, especially with a developed industry. The reasons why lichens do not grow in cities are quite understandable. The air in the cities is polluted, which lichen is an unacceptable condition. The fact is that for most representatives of lichens, conditions of high oxygen content in the air are important. But this does not mean that the urban area cannot find lichens at all. They do not grow in industrial areas, and on the outskirts you can find tree trunks covered with thalli of this biological species.
What lichens grow in Russia?
On a vast territory Russian Federation grow a variety of lichen species. IN spruce forests you can find gray bedspreads of the bearded lichen descending into the branches. When visiting a pine forest, one often finds entire colonies in the form of patterned bedspreads crisp underfoot. 
earth from white, gray and even pink bushy lichens. We mentioned another type of fruticose lichen earlier - this is reindeer moss, better known as "deer moss". In the harsh conditions of the tundra, the deer living there feed on this particular mushroom algae.
Sometimes on stones in almost any region of the country you can find like a frozen gray-brown foam. It is formed by the so-called scale lichens.
Leaf lichens are also found in nature (for example, wall xanthoria), which forms a bizarre multi-colored pattern of plates. They cover not only stones, but also tree trunks and branches.
Question 1. What is a mycelium?
Mycelium - the vegetative body of the fungus, formed by thin branching threads - hyphae.
Question 3. What is symbiosis?
Symbiosis (from the Greek symbiosis - cohabitation, cohabitation) is a type of interspecies relationship between organisms: coexistence that is beneficial for individuals of both species or at least one (nodule nitrogen-fixing bacteria on plant roots).
Question 1. Where are lichens found?
In a dark spruce forest, from old branches to the very ground, shaggy gray beards bearded lichen. In dry pine forests, a continuous carpet of branched pink, gray and white lichens is formed. They crunch underfoot in dry weather. These are bushy lichens. Known as "reindeer moss", the fruticose moss lichen is widely distributed in the tundra. Scale lichens settle on the stones, similar to frozen brown-gray foam. Leafy lichens are widespread in the form of plates of different colors. They grow on rocks and on the bark of trees. Of these lichens, golden-yellow wall xanthoria is especially common on the bark of aspens.
Question 2. How are lichens arranged?
The body of a lichen - thallus - consists of a fungus and algae living in symbiosis as one organism. It is formed by intertwining threads of mycelium, between which are unicellular green algae or blue-green (cyanobacteria). Suction cups sometimes appear on mushroom threads, which penetrate into the algae cell.
Question 3. How do they eat?
The threads of the lichen fungus absorb water and dissolved in it minerals, and organic substances are formed in the cells of green algae. The algae that enters the body of the lichen, separated from the fungus, as a rule, can exist independently. The fungus cannot live separately from the algae.
Question 4. Why are lichens called the pioneers of vegetation cover?
Lichens are the first to settle in the most barren places. By releasing special acids, lichens slowly destroy rocks. When they die, they form soil on which other plants can live.
Question 5. What is their practical significance?
In the North, they serve as the main food for deer in winter. From some types of lichens, paint and litmus are obtained, which is necessary for the chemical industry. Many types of lichens are used in medicine and the perfume industry.
Question 6. What is the phenomenon of symbiosis?
The phenomenon of symbiosis consists in the relationship between organisms under such conditions that coexistence is beneficial for individuals of both species.
Question 7. What other examples of symbiosis are you familiar with?
Fungus and algae in lichen, nodule nitrogen-fixing bacteria on plant roots, fungi and trees.
Think
Why are lichens considered as a special group of organisms?
Lichens represent a peculiar group of complex organisms, the body of which always consists of two components - a fungus and an algae. How are lichens different from other plants? Firstly, a specific feature of lichens is the symbiotic cohabitation of two different organisms - a heterotrophic fungus and an autotrophic algae. Not every cohabitation of fungus and algae forms a lichen. Secondly, lichens form special morphological types, life forms of external and internal structure, not found separately in the fungi and algae that make up the lichen thallus. Thirdly, lichens differ significantly from other groups of organisms, including free-living fungi and algae, in their special biology: methods of reproduction, slow growth, and attitude to environmental conditions.
Quests for the curious
Air pollution is detrimental to most lichens, so the presence of lichens indicates the purity of the air in the area. Study the lichens in your area. Determine what forms of lichens are found here. Make pictures and descriptions of them. Make a conclusion about the purity of the air in your area.
Parmeliopsis doubtful. Thallus in the form of rosettes up to 10 cm in diameter, consists of thin-skinned lobes dissected along the edge, tightly fused with the substrate. The upper side is orange-yellow, sometimes dark greenish, densely covered with yellowish-greenish capitate sorals; the lower one is almost black, densely covered with dark rhizoids. Habitat. On trunks and branches of coniferous and deciduous species (especially often on birch); common on twigs of shrubs, dwarf shrubs, treated wood and stumps. Spreading. Throughout Russia in coniferous and mixed lowland and mountain forests. One of the most common lichens.
Bryoria is hairy. Thallus bushy, hanging, 10–20 cm long, greenish-white. The branches are filiform, slightly branched, thin (0.15–0.3 mm in diameter). Spreading. Buryatia, the species is distributed in the European part of Russia, in the Urals, the North Caucasus, Siberia and Far East. Habitat. It grows in old-growth dark coniferous and black forests, on the trunks and branches of predominantly dark coniferous species.
Cetraria Icelandic. Its thallus looks like a loose turf up to 10-15 cm high. It is formed by flat, sometimes grooved-folded lobes. The lower surface is lighter in color, it is light brown, almost to white, with numerous white spots and ruptures in the bark, which serve to penetrate the air. ground lichen representative pine forests, moorland, swamps, tundra and forest-tundra. It grows directly on the soil or on the bark of old stumps. Prefers sandy unshaded places, where it sometimes forms almost pure thickets. Grows only in clean air.
Evernia is mesomorphic. Thallus is bushy, erect, often hanging, 2.5-10.0 cm long. Lobes 1.0-2.5 mm wide, branched, more or less flattened, sometimes slightly rounded, radial in structure, equally colored on both sides. Grows on tree bark, treated wood, occasionally on mossy soil. Found in temperate and tropical zones Asia, Europe, North America including Mexico, Arctic zone. In Russia - throughout the territory.
Conclusion: these are far from all lichens, but even by the presence of these, we can say that the air in our forests is clean.
Lichens are a special group of organisms consisting of two completely different species. One part of a lichen is green algae (belongs to plants) or blue-green algae (belongs to bacteria). The other part of a lichen is a fungus.
Lichens are studied by science lichenology which is considered a branch of botany.
There are more than 25 thousand species of lichens.
Lichens are unpretentious and therefore widespread. They can be found even in permafrost conditions or on bare rocks. They can grow on tree trunks and the ground. Lichens living in the tundra spread along the ground in a continuous carpet.
The color of lichens varies from yellow and gray to brown and black.
According to the shape of the thallus, three types of lichens are distinguished.
fruticose lichens connected to the surface on which they grow, only at their base. Bearded lichen grows in spruce forests, where it hangs from tree branches. Reindeer moss (reindeer moss) grows on the soil. If you step on it in dry weather, you will hear a characteristic crack.
foliose lichens found on tree trunks. They look like plates of different colors and shapes. So golden-yellow xanthoria grows on aspen. Leafy lichens are connected to the substrate by rhizoid-like outgrowths. They are easily removed from the surface.
scale lichens(crustal lichens) appear as brownish and greyish crusts on stones and rocks. They adhere tightly to the surface, as a result of which it is difficult to tear them off from it.
Lichens are most often considered an example of symbiosis, in which two different organisms beneficial cohabitation.
The body of a lichen is called thallus. It consists of fungal hyphae, between which are single-celled green algae or blue-green algae.
Such cohabitation allows lichens to live where neither fungi nor algae can live separately. The hyphae of the fungus provide the algae with water and minerals. Algae provides the fungus with organic substances that it synthesizes in the process of photosynthesis.
Since algae have to feed not only themselves, but also the fungus, lichens grow very slowly. Also, often growing in places with permafrost, lichens do not get enough water. So the growth of bushy lichens can be several millimeters per year, and scale - in general, fractions of a millimeter. However, lichens live long enough (up to 100 years).
Lichens reproduce asexually. Algae cells divide into two, and the fungus forms spores. Also, special groups of cells can form in the lichen thallus. These groups leave the parent lichen and give rise to a new organism in a new place.
The meaning of lichens
Lichens are the first to colonize places where there is no soil. Gradually dying off, they form humus. Also, lichens secrete acids, which leads to the destruction of rocks. As a result of mixing destroyed rocks and humus, soil is formed on which plants can grow.
Yagel serves as food for deer in the tundra. It is also used as pet food.
Icelandic moss is eaten by humans.
From a number of lichen species, litmus (a chemical indicator) and antibiotics are obtained.
Oak moss is used in perfumery. It gives strength to spirits.
Lichens are ecological indicators. They die in polluted air. Therefore, by the absence or presence of lichens in a certain area, one can judge the ecological situation.
Question 1. Where are lichens found?
Fruticose lichens are found in dry pine forests, in the tundra. Scale lichens settle on stones. Leafy lichens grow on stones and on the bark of trees.
Lichens are found in a variety of habitats from the North Pole to the South Pole. They grow on stones and rocks, tree bark and plant leaves, soil, artificial substrates. Some lichens live in water.
Question 2. How are lichens arranged?
Lichens are organisms whose body is formed as a result of the symbiosis of a fungus and an algae. The body of a lichen is called a thallus (thallus). The photosynthetic component of a lichen (algae or cyanobacteria) is called a phycobiont (gr. fikos - algae), and the fungal component is called mycobiont (gr. mikos - fungus). The most common phycobionts are green algae and cyanobacteria. In total, about 100 species of phycobionts are part of lichens. This means that one phycobiont species can have several fungal components. In modern flora, there are about 13,500 species of lichens.
Question 3. How do lichens eat?
Mushroom filaments have suction cups that penetrate into the algae cell. Thus, the mycelium receives the organic substances it needs for nutrition from the cells of green algae. In turn, the filaments of the lichen fungus absorb from environment water and minerals dissolved in it, which enter the algae cells.
Question 4. Why are lichens called the pioneers of vegetation cover?
Lichens- pioneers of vegetation, they are the first to master lifeless substrates, making them suitable for other organisms over time. Lichens in their nutrition practically do not depend on the soil and are the first to settle in the most barren places. By releasing special acids, lichens slowly destroy rocks. When they die, they form soil on which other plants can live. Therefore, lichens are called the pioneers of vegetation cover.
Question 5. What is the practical importance of lichens?
Lichens are indicators of air pollution, especially sensitive to the content of sulfur dioxide in the atmosphere. They are used in archeology and geomorphology to determine the age of the substrate.
Lichens serve as food for animals, especially in winter time in the northern regions (for example, reindeer moss, or reindeer moss). Birds can use lichen thalli as construction material for their nests. Some lichens are also edible for humans.
A number of substances used in the perfume industry are obtained from lichens.
Some lichens are used in folk medicine in the treatment of a number of diseases.
From some types of lichens, paint and litmus are obtained, which is necessary for the chemical industry.
Question 6. What is the phenomenon of symbiosis?
Symbiosis- this is a connection that is useful both to one and to another organism.
Question 7. What other examples of symbiosis are you familiar with?
Symbiosis occurs, for example, between certain types of trees and fungi. The threads of the mycelium tightly braid the root of the tree and even penetrate into it, forming a fungus root, or mycorrhiza. The tree receives from the mycelium the water and dissolved minerals absorbed by it from the soil. In turn, the mycelium receives from the roots of trees the organic substances it needs for nutrition and the formation of fruiting bodies.
Collier Encyclopedia. - Open society. 2000 .
See what "LICHEN" is in other dictionaries:
- (Lichenes), organisms formed by the symbiosis of a fungus (mycobiont) and algae (phycobiont); traditionally referred to as lower plants. Early fossil L. presumably attributed to the top. chalk. Occurred as a result of the transition of some representatives ... ... Biological encyclopedic dictionary
Organisms that are a symbiosis of a fungus (mycobiont) and algae (phycobiont). In L., apparently, there is no strict selectivity between partners - the fungus can exist with different types algae, and algae - with different fungi. ... ... Dictionary of microbiology
LICHEN- Lichens, lichens, Lichenes, a peculiar class of lower plants, consisting of fungus and algae, forming together one organism. Lichen fungi, with few exceptions, are marsupials. Algae L. bear the common old name gonidia. Not… … Big Medical Encyclopedia
Polyphyletic group of fungi Ernst Heinrich Haeckel ... Wikipedia
- (Lichenes) a specialized group of fungi that are in constant cohabitation with algae; some botanists consider L. as an independent group of lower plants. The science of L. is called lichenology (See Lichenology). ... ... Great Soviet Encyclopedia
lichens- ▲ lower plants lichens are symbiotic organisms formed by fungus and algae. reindeer moss, reindeer moss. cladonia. cetraria. | manna. soredia. | lichenology. bog down. mossy. suede. mossy (# stump) ... Ideographic Dictionary of the Russian Language
lichens- kerpės statusas T sritis ekologija ir aplinkotyra apibrėžtis Organizmų grupė, kurių kūnas sudarytas iš grybo ir dumblio simbiozės. atitikmenys: engl. lichen vok. Flechten, f; Lichenen rus. lichens, m ... Ekologijos terminų aiskinamasis žodynas
Yageli, spore-bearing plants, fungi and algae cohabitate in the body. Fungal cells and algae cells are exchanged by assimilation nutrients: the first give water and minerals and receive organic from the second ... ... Agricultural dictionary-reference book
Books
- Biology. Plants, bacteria, fungi and lichens. Grade 6, V. P. Viktorov, A. I. Nikishov, The textbook was written in accordance with the mandatory minimum content of biological education and the requirements for the level of preparation of students in the main (basic) school. It contains the essential… Category: Additional Tutorials Publisher:
