Mosses, they are bryophytes - these are spore plants that have a stem, green leaves, but devoid of roots, vascular systems, flowers and seeds. Scientists, however, do not consider the organs of mosses to be real stems and leaves, but we will not go into scientific subtleties now.
Mosses are small plants. Most land mosses only reach a few centimeters in height. There are Lilliputians who are five times smaller than a millimeter. But among aquatic mosses there are real giants with a meter-long stem. The modest size of mosses is probably due to the absence of a conductive system. Without it, how would they deliver water and nutrients to all ends of a large body?
Mosses have short, thread-like outgrowths of the lower body. They resemble roots, but serve mainly to attach to the soil. And mosses absorb water with the entire surface of the body.
Sometimes the name moss is used, confusing different plants. For example, the well-known “deer moss” () is not a moss at all, but a plant from a completely different group, it is a lichen.
Where does moss grow?
Mosses are common inhabitants of damp, shady places. They can be found on rotting wood, trunks and branches, rocks, stones, concrete, along the lower edge of buildings where moisture accumulates. Sometimes they appear on rooftops and between paving stones. It is not surprising that these lovers of moisture have also mastered reservoirs.
Having drilled a glacier in Antarctica not so long ago, the British discovered moss that had lain here for one and a half thousand years, since the time of the Roman Empire. Moreover, the moss placed in the water sprouted! This suggests that once in Antarctica it was the same as in the Northern Hemisphere.
It is widely believed among tourists that mosses often settle on the northern side of large stones, rocks, tree trunks. The north side is really more often and longer wet. But this does not happen everywhere and not always. Yes and different types mosses have different requirements for moisture and light. So mosses can settle from any part of the world, and you need to be careful on this basis.
How is moss different from algae?
The main differences between mosses and algae are that mosses:
How are mosses different from ferns?
Mosses cannot be confused with ferns because mosses:
- no real large leaves and long roots;
- specialized tissues are very poorly developed;
- cells have a half, not a double, set of chromosomes for most of their lives;
- spores do not ripen on leaves, but in a box, which is connected to the stem with a leg;
- a branched thread grows out of the spore, and not a small plate;
In addition, mosses are not treelike and appeared on the planet before ferns.
What is moss good for?
Like other living organisms, mosses are important in the general cycle of matter. They provide food to many animals and microorganisms, and change their habitat in the course of life. For example, covering the soil with a dense carpet, they can lead to waterlogging. Unpretentious mosses are among the first to settle where it is difficult for other plants to live (for example, in the tundra). Dying and decomposing, mosses enrich the soil with humus. Many frogs lay their eggs in the moss, and bird nests are lined with moss.
Man has long used swamp moss sphagnum. It grows to the top, the rest of the stem dies off. But since the plant contains phenol, which is deadly for bacteria, it almost does not rot. Gradually accumulating and compressing at the bottom of the swamps, moss forms a common fuel and chemical raw material - peat.
Another property of sphagnum is the ability to absorb huge amounts of moisture. Therefore, dry moss is used as bedding for livestock, and during the war it happened to replace bandages. 
In addition, many mosses are very decorative, their bright green pads adorn aquariums, greenhouses, garden compositions, etc. In the ancient capital of Japan, the city of Kyoto, there is the Saihoji Monastery, where the Moss Garden has been created for a century now. It is recognized as a UNESCO World Cultural Heritage Site. Instead of lawn grass and flowers cover the ground here with mosses. There are 130 of them here. They decorate miniature ponds, moss rugs surround rocks and trees.
Mosses generally easily absorb not only moisture from the air, but also many chemical substances. This makes it possible to detect atmospheric pollution using these plants. By the way, the destruction of the natural environment threatens many mosses with extinction. The Red Book of Russia includes 60 species of mosses.
Bryophyte department- these are higher spore plants, the species diversity of which reaches 20 thousand. The study of mosses has been going on for many centuries, the scientists involved in their research were called bryologists, they founded a separate botanical branch dedicated to bryophytes - bryology. Briology - the science of mosses, studies the structure, reproduction and development of bryophytes (actually mosses, liverworts, anthocerotes).
General characteristics of mosses
Moss - general characteristics
Bryophytes are one of ancient plants that inhabit our planet. The remains are found in fossils from the end of the Paleozoic era. The distribution of mosses is associated with a preference for a humid environment and shaded areas, so the majority inhabit the northern part of the Earth. Poorly take root in saline areas and deserts.
Bryophyte classes
Leafy mosses is the most numerous class. Plants are composed of stem, leaves and rhizoids.
Stem can grow vertically or horizontally, divided into bark and main tissue (contains water, starch, chloroplasts for photosynthesis).
Stem cells can produce filamentous processes - rhizoids, necessary for anchoring to the soil and absorbing water. They are often located at the base of the stem, but can cover it along its entire length.
Leaves simple, often attached to the stem at a right angle, in a spiral. Leaf blades are equipped with chloroplasts, in the center there is a vein (serves to carry nutrients).
Deciduous mosses can reproduce by stems, buds, branches, which give rise to the formation of solid carpets of mosses that cover the ground. The class of leafy plants includes sphagnum mosses (they have a variety of stem colors - light green, yellow, red), andreevy and bry mosses.
liverworts found on the coasts, swamps, rocky terrain. Distinctive features: leaves do not have a vein, dorsoventral structure, a special mechanism for opening the sporophyte.
The leaves are arranged in rows, have two lobes (the lower lobe is often wrapped and serves as a reservoir for water), rhizoidal processes are unicellular. During the rash of spores, the sporophyte box opens into separate valves, and elaters (spring formations) contribute to the dispersion of cells.
Reproduction can be carried out with the help of buds (vegetatively), which are formed at the upper pole of the leaves. Representatives of the class pella endievistnaya, milia anomalous, moss marchantia, etc.
Anthocerotus mosses inhabit the tropical zone. The multinuclear body (thallus) has a rosette shape, consists of the same type of cells. In the upper balls of cells are chromatophores (contain a dark green pigment). The lower part of the thallus gives rise to processes, rhizoids, the body itself forms cavities filled with a viscous fluid that maintains constant moisture.
On the surface of the thallus, under adverse conditions, tubers are formed that are resistant to low humidity; after a period of drought, a new generation is formed. Plants are monoecious, reproductive organs develop in the thickness of the thallus, the sporophyte stage is predominant. Anthocerotes include folioceros, anthoceros, notothilas, etc.
How do mosses reproduce?
There is an alternation of asexual and sexual reproduction in the life cycle of mosses. The asexual period begins with the formation of spores and their germination on moist soil (a pregrowth is formed, thin thread, which gives life to male and female individuals). There are two types of mosses:
monoecious- male and female organs reproductions are on the same plant.
Dioecious- Reproductive organs are located in different representatives of the sex.
After the spore germinates, the moss life cycle enters the sexual phase. The organs of sexual reproduction are antheridia (male) and archegonia (female). Representatives of males are weaker than females, smaller in size, after the formation of antheridia they die off.
Spermatozoa are formed on male plants, eggs on female plants, after their fusion a zygote is formed (located on the female, it feeds the immature sporophyte), which later develops into a sporangium. After maturation of the sporangium, it opens, spores spill out of it - the asexual reproduction period of mosses begins again.
Reproduction of offspring is possible in a vegetative way, mosses form thalli (green branches), buds, tubers, which take root well on moist soil.
What is the importance of spores in the life of mosses?
Spores are the cells that mosses need to reproduce. Moss plants do not bloom, do not have roots, therefore, in order to continue the genus, they have formed a sporophyte with sporangia (the place where spores ripen).
The sporophyte has a short life cycle; after drying, the spores disperse around, and when they get on moist soil, they quickly take root. Under unfavorable conditions, they can persist for a long time without germinating, resistant to low and high temperatures, prolonged droughts.
The value of mosses in nature and human life
Mosses are food for many invertebrates.
After dying, they give deposits of peat, which is necessary in the production of plastics, resins, carbolic acid, and is used as fuel or fertilizer.
Moss completely covers the ground in places of growth, which leads to the accumulation of moisture and waterlogging of the territory. Thus, the germination of other vegetation becomes impossible. At the same time, they prevent erosion, soil destruction by surface water and winds. When the mosses die off, they take part in the formation of the soil.
Able to grow in places of fires, persistent and hardy, they inhabit the territory of the tundra (the main vegetation background, since other plants cannot survive in such conditions).
In wartime, sphagnum moss was used as a dressing because of its bactericidal properties and ability to absorb moisture.
With the help of mosses, you can navigate the terrain: they do not like light, therefore they are located on the shady side of stones and trees. Moss points the man to the north.
In construction, it is used as an insulating, insulating material.
Tests
620-1. The accumulation of what group of plants contributes to waterlogging of the soil?
A) lycopsform
B) horsetail
B) mossy
D) ferns
Answer
620-2. The stem with leaves in the process of evolution first appeared in
A) algae
B) mossy
B) horsetail
D) ferns
Answer
620-3. Mosses represent a dead end branch in plant evolution because
A) more highly organized ferns originated from them
B) they did not give rise to more highly organized plants
C) more highly organized horsetails originated from them
D) they evolved from unicellular algae
Answer
620-4. What are the characteristics of mosses?
A) adventitious roots develop from the stem
B) spores are formed in a box
C) they have no escape
D) pollination precedes fertilization
Answer
620-5. Mosses develop from spores
A) a box on a leg
B) seed
B) green thread
D) sprout
Answer
620-6. The adaptability of sphagnum moss to life in conditions of excessive moisture is manifested in the presence of
A) rhizomes with adventitious roots
B) cells with chloroplasts
B) dead cells
D) rhizoids
Answer
620-7. Representatives of which department of the plant kingdom are shown in the figure?
Answer
620-8. What plants belong to the Bryophytes department?
A) living on land and reproducing by seeds
B) leafy, without roots, reproducing by spores
C) all plants in wet habitats
D) all herbaceous plants
Answer
620-9) What are the adaptations for absorption a large number water appeared in the process of evolution in mosses?
A) rhizoids - outgrowths on the stem
B) large dead cells
B) spore boxes
D) cells of thin integumentary tissue
Answer
620-10. In green mosses, unlike algae,
A) cells have large and small nuclei
B) fertilization occurs in the presence of water
C) the thallus is divided into tissues and organs
D) sexual and asexual reproduction
Answer
620-11. What division of higher plants does the plant shown in the picture belong to?
A) angiosperms
B) Gymnosperms
B) ferns
D) Bryophytes
Answer
620-12. How are bryophytes distinguished from other plants?
A) in the process of their development, alternation of generations occurs
B) reproduce by spores
B) have leaves, stem and rhizoids
D) capable of photosynthesis
Answer
620-13. Ferns, unlike green mosses, have
A) rhizoids
B) roots
B) leaves
D) stems
Answer
620-14. From dispute green moss cuckoo flax develop(s)
A) a growth in the form of a green plate
B) pregrowth in the form of green threads
B) plants with leaves
D) seeds of the future plant
Answer
620-15. Higher plants have no roots
A) Tsvetkov
B) conifers
B) moss
D) Ferns
Answer
620-16. Ferns are much more widespread on Earth than mosses, since they
A) have a developed root system and multiply more efficiently
B) appeared in the course of evolution earlier and managed to better adapt
C) are widely grown by man for their needs
D) successfully distributed by various animals
Answer
620-17. Mosses have the simplest structure among higher plants, since
A) they have no roots
B) their stem is unbranched, with narrow leaves
C) they form organic substances from inorganic
D) they have air cells
Answer
620-18. Why do mosses represent a dead end in plant evolution?
A) they have not mastered the ground-air habitat
B) they evolved from algae
C) they do not have roots and reproduce by spores
D) they did not give rise to more highly organized plants
Answer
620-19. What department of the plant kingdom is represented in the picture?
A) ferns
B) Gymnosperms
B) Lycopsoid
D) Mossy
Answer
620-20. Which group of organisms includes green plants that do not have roots, reproduce by spores, in the life cycle of which the sexual generation predominates?
A) bryophytes
B) ferns
B) gymnosperms
D) lycopsform
Not everyone knows about what mosses are (the name of the species, genus). At best, from a school biology course, everyone remembers the familiar cuckoo flax or sphagnum. In fact, a fairly large group of these plants stands completely apart from other currently existing ones. No connections or transitional, intermediate forms were found. IN ordinary life very often they confuse not only the names of mosses and lichens, but also the plants themselves, meeting them, for example, in the forest. Why not deal in more detail with these amazing inhabitants of planet Earth.
Mosses are one of the most ancient plants on Earth.
moss breeding
These plants have a peculiar reproduction cycle. The names of mosses and their distribution are different, but they are all similar in that the gametophyte and sporophyte are combined in one plant. The latter is also called the asexual generation. It is represented by a small box with spores, which is fixed in the gametophyte with the help of a sucker leg. The development of the sexual generation begins from the moment the spore germinates. Initially, a filamentous or lamellar formation (protonema) develops, on which buds are laid, from which then a lamellar thallus or stems with leaves grow, depending on what types of mosses they are. The names of the organs of sexual reproduction of higher plants are familiar to many from school - these are archegonia and antheridia. The former are female reproductive organs characteristic of higher spore plants, as well as a detachment of gymnosperms. Antheridia are male organs found in higher plants and algae.
Classification
Let us dwell in more detail on the question of what mosses are. The names of the two existing classes are very unusual: hepatic and leafy. Previously, Anthocerot mosses were also included in the classification. But later scientists came to the conclusion that this various groups plants and allocated them to a special department. Each class has its own specific features and characteristics.
Class Liverworts or Liverworts: types of mosses, names and photos
A distinctive feature of all species of these plants lies in the wide variety of gametophytes and the similarity of sporophytes. The total number of the class is about 300 genera and 6,000 moss species. They grow mainly in tropical climates. It is very typical for them vegetative propagation more or less developed parts of the thallus.
There are species that are not fixed either on the soil or on trees, for example, floating Riccia. Under natural conditions, it is found in the territory Far East and Ciscaucasia. Sometimes it is also bred in aquariums.
On the territory of Russia, a diverse marchantia is also quite common. This moss grows on soil. The body of the plant (thallus) has the form of a multi-layered, strongly branching plate and measures up to 10 centimeters. The plants are dioecious, and the reproductive organs are placed above the plate on special stands in the form of an umbrella.
What are the generic names of mosses of the liverwort class? We list some of them: spherocarpus, pallavicinia, symphiogina, merchia, hymenophytum, metzgeria, richcia.
Class Leafy mosses: examples, names
This is the most numerous class, which includes more than 15,000 species united in 700 genera. In addition to being numerous, they also differ important role in the vegetative envelope of the earth. The gametophyte in representatives of this class can grow vertically upwards or in a horizontal plane. Depending on this, they are divided, respectively, into orthotropic and plagiotropic species. For convenience, leaf-stemmed mosses were divided into three subclasses: sphagnum, andreevy, briiye.
Subclass Sphagnum mosses
Everyone knows these names of mosses. There are more than 300 species of plants included in the subclass (40 species are found in our country), and they grow all over the world. All representatives of the species are quite large in size and color white-green, brown or red. Basically, the species of this subclass make up the vegetation of the tundra zone and are the main source of the formation of peat deposits.
The genus Sphagnum, or peat moss, includes 120 species. They all grow in swamps, covering them with a continuous carpet. Stems annually give an increase of 2-3 cm, while the lower part dies and decomposes, but does not rot. The reason for this feature is that carbolic acid is formed in the body of the moss, which is an antiseptic. The dead part forms peat, but this process is very slow. So, it was calculated that 1 meter of such deposits is formed within 1,000 years!
Another representative of the subclass under consideration is the rural tortula. This moss grows on has an unusual. Habitat: from tundra to arctic desert zone. Attaches to bare tree roots and bark, as well as stones. It has a characteristic brown or greenish-brown color, the stem grows up to 10 centimeters.
Here are some names of mosses of the genus under consideration: bulging, brown, Girgenzone, Magellanic, papillose.
Subclass Brie mosses
The subclass is quite numerous and includes more than 14,000 species, 1,300 of which are found on the territory of Russia. Mainly perennials, reaching very impressive sizes: from 1 mm to 50 cm in height. The color is usually green, red-brown or even almost black. They grow, as a rule, on the soil, rotten trees or on leaves. They absolutely cannot stand salty soils. Well known to everyone are such names of mosses in Russian as kukushkin flax, or scientifically ordinary polytrichum, hairy brium. They grow in the north and most often in the forest.
Subclass Andreeves
This is a group of small plants (about 120 species) growing in cold climatic conditions (Arctic and Antarctic). They can be found on stones and rocks, on which they form something like pads. Representatives of this subclass are rocky andrea, red and yellow splachnum, rosette-shaped rodobrium, gray leucobrium, drooping poliia, centipede dicranum. These are just some of the mosses. The names and photos of other representatives of the subclass can be found in botanical atlases, where it will also be given detailed description genus and species.
Division Anthocerota
Antrocerotes were previously considered as mosses and stood out in a separate class. Now they are defined as having a thallus similar in structure. The thallus is characterized by a rosette shape, on the underside there are rhizoids. These are inhabitants of the tropics, and only a few species grow in temperate climates.
How to distinguish moss from lichen?
People very often confuse not only the names of mosses and lichens, but also their appearance in general. The main difference is that the latter are representatives of lower spore plants that appeared on Earth much earlier than mosses. Some lichens even have a name that directly indicates that they belong to a completely different group of plants. For example, oak moss, Irish moss, deer moss. The original names have been preserved, but they have nothing to do with the Bryophytes department under consideration. oak moss has a beautiful scientific name Evernia Plum. If you look at the photo, it will immediately become clear that this is a lichen. It grows, as the name implies, on the bark of oak, as well as some coniferous plants.
The body of lichens is a symbiosis of algae and fungus. They do not have roots, and mosses have their likeness - rhizoids. To put it even more simply, the body of a lichen is like a sandwich: a fungus on top and bottom, and algae in the middle, which carry out the process of photosynthesis. The substrate to which the lichen is attached (most often trees) is destroyed by the action of a special acid secreted by fungi. Moreover, it is capable of destroying even stone. Therefore, these plants are quite harmful. So, when they appear, for example, on fruit trees, they simply destroy the bark. But at the same time, lichens are an indicator of the purity of the air, because they absolutely cannot tolerate gas pollution.
Ferns in evolutionary terms are one step higher than mosses. This is explained by the fact that they have a vascular conducting system, through which water and minerals dissolved in it enter the plant. They are more familiar to people and are found everywhere in forests. Shield and bracken are well-known names. Mosses and ferns are nevertheless united by one significant similarity: both of them reproduce not by seeds, but by spores. That is, there is an alternation of sexual and asexual generation (sporophyte and gametophyte). In addition, they are very often neighbors in their natural habitat, as they both prefer shade and high humidity.
The meaning of mosses
Mosses in their natural environment are pioneers, they are the first to inhabit territories whose climatic conditions are sometimes not suitable for any other plant. These plants are an integral part of the entire biosphere as a whole. Mosses create special biocenoses in the tundra, covering the ground with a continuous carpet.
They have a very pronounced ability to retain moisture, the benefits of which can be interpreted from two sides. From the first point of view, they regulate the water balance in the soil, and from the second point of view, they contribute to the waterlogging of forests, meadows and agricultural lands.
Sphagnum mosses are the most valuable source of peat deposits, which are widely used as fuel, material for construction and in agriculture. In addition, some species are used in medicine, as they have antibacterial properties. But the formation of sphagnum and hypnum bogs is also essential for the entire ecosystem as a whole. This is the habitat of many shrubs and herbaceous plants, home to numerous game animals and birds. But most importantly, the swamp is something like a reserve reservoir with fresh water. After all, like a sponge, absorbing all the precipitation, it then gradually releases moisture into the soil to small streams that flow from it. The swamp plays the role of a moisture regulator in the surrounding area.
