Mokhovidny are the most primitive group of ground plants of the modern world, which has preserved many similar features with algae.
Mosses are the department of perennial (usually) higher plants, the main difference of which is the regressive development of dumpy, which is studied by briology.
The history of mossy plants
There is no one opinion in the science of the origin of this department of plants you can only name several hypotheses regarding this moment. Some researchers are inclined to the idea that this department is reduced vascular plants, and many believe that both mossy and vascular descended from separate types of algae.
If we talk about the origin, then this type of flora is evolutionarily a dead end (or more simply, blind) branch of plant development, which are close in structure to algae. Many of the Mookhovitable for their reproduction need an aquatic environment
Many studies confirm that the mocking, like most spores, are originating from the psilophytes, which are called a group of extinct ground representatives of the flora. And it is precisely the sporophyte of mosses (the multicellular phase producing disputes) in science is considered the final result of the weakening of the sporophyte of many ancestral types.
Moss and vascular plants are two different evolutionary routes of the formation of higher plants and are characterized by the presence of one distant ancestor algae is supposedly this species.
Mosses are a separate plant department, since they completely absent such elements that are familiar to plants as flowers, roots, and even conducting system. This type of flora is propagated with the help of dispute, ripening in the organs of asexual reproduction (sporangia) in sporophytes. Unlike vascular, mossy plants in the life cycle prefer haploid sexual generation, t.e. gametophyte with a single set of chromosomes characterized.
Such a gametophyte is a perennial green formation (necessarily with lateral processes of leaflike shape risoids), while the asexual stage of the cycle, or sporophyte, is a shortlived formation, the structure of which is the leg and box, where the possibility of ripening disputes have the opportunity to ripen.
Such a sporophyte (it is still commonly called sporgeonia), has a more elementary structure than in any other group of higher plants: so, it is not able to take root and is usually located directly on the gametophyte.
The structure of the sporophyte includes several elements:
With mosses, you should not confuse lichens the same deer moss, which is a collective designation for some species precisely lichens.
The roots of a mossy plant
Mookhovid plants, just like any algae, are distinguished by a complete absence of roots: at this department, risoids replace them processes of integumentary fabric. These processes (as well as the processes of algae) can only hold the plant on the surface of the soil, but they cannot ensure the supply of water and its absorption. That is why mosses (and algae) are able to absorb water with the entire surface of their body and first of all, this applies to leaves.
Fabrics of mossy plants
The most important element of the structure of each plant belonging to the ground is its integumentary tissue, which protect the living organism from drying. All terrestrial plants have this type of tissue, only in the mossy such fabrics are an order of magnitude weaker than it exists in vascular plants.
Quite often, cover fabrics differ in a lower level of specialization and include chloroplasts, which means that they perform not only a protective, but also a photosynthetic mission. Most of the Molovicular (the same sphagnum) have leaves consisting of a single layer of cells, t.e. do not have differentiated covering elements.
The presence of fabrics of this type automatically also implies the presence of ustits (holes), the purpose of which is the implementation of gas exchange. But you need to understand that in most mosses these holes function and are organized completely differently from how this happens in vascular plants. This body is not able to regulate gas exchange through a constant opening process. The mouth of the mossy are open on an ongoing basis and are closed only in the event of the body drying out.
Most of the representatives of this department are absent or simply poorly developed, conducting fabrics. Some of the mossy are equipped only with hydroeades (dead cells), and in the most complex plants from this department (the same green mosses) a kind of stalk from a photosynthetic generation in structure resembles vascular plants.
Most of the mossy are also characterized by the absence of specialized tissues of the mechanical nature, and their hydroeades do not have special thickenings that allow the cells of vascular plants to carry out a supporting function. And precisely because such species of plants do not have a wellformed conductive and mechanical fabric, most of them do not differ in large sizes usually their height is not more than 20 cm.
The stem of mossy plants
The body of a mossy plant, as well as the body of algae, was called the layout, but it was in mosses that the presence of a clear distinction on the stem and leaves can be traced.
Most of the mossy have a conducting system formed in the form of individual bundles and ensures the movement of substances necessary for the plant (mineral and organic), and water.
In mossy leaves, the leaves are organized as thin plates of green color with a foundry-lanceolate form, consisting of one (maximum-only a few) layer. Such a sheet usually contains colorless cells and acumulators with green color containing chlorophyll and responsible for the process of photosynthesis.
Many mossy are equipped with risoids rootlike processes in the lower part of the stem peculiar outgrowths of the epidermis resembling root hairs in their device. Such processes can replace the roots with their functionality as a rule, they fix the plant in the ground and ensure the absorption of water and minerals.
Signs and characteristics
Mookhoid plants can be found on all continents of the planet even on Antarctica, and they are able to exist in the most extreme conditions.
As a rule, the mossy form quite powerful clusters, preferring shaded places, often very close to water, but these plants can also exist in dry areas located in relatively open areas. And some species of mossy are able to live even in freshwater reservoirs, and even in sea water, a strip of surf.
Mookhovid, or Briophytes, are a plant department, the number of which has about 20 thousand diverse species all of them formed about 7 hundred births and more than a hundred families.
Mokhovid, as a rule, are, with rare exceptions, small plants, the height of which is not more than 30 mm: the exception is aquatic mosses they reach a length of up to half a meter, and epiphytes are even longer.
Earlier, in addition to leafsteen mosses, hepatic mosses, as well as antocerot mosses, were considered in this department, but today these taxa make up their own department. Previously, to indicate their combination, informal term mossy termous was used.
Plants belonging to the mocking are characterized by the alternation of haploid and diploid generation, and, unlike vascular, the mosses are dominated by the haploid generation.
Most important organs and tissues are poorly developed in the mossy plants that were formed in mind the need to adapt to a groundbased existence: first of all, it is leading fabric, mechanical and cover; They also do not have a root system that replace risoids. Like algae, mossy can absorb moisture with the entire surface of the body; For successful propagation, they need the presence of a drop-liquid environment-male gametes move in liquids.
The value of mossy plants
In nature, mosses usually first appear on an uninhabited substrate and it is their role that is recognized as dominant in the process of biocenosis, where they are able to cover soil like a carpet in the tundra, for example. Mosses hold the championship in the process of regulating the water balance of territories here they are characterized by the ability to absorb an almost limitless amount of liquid, as well as hold it.
In the activities of a person of mosses, causing soil caught by soils, they are able to influence the deterioration of soil quality suitable for use in agriculture. However, growing, they are able to serve as the prevention of soil erosion, absorbing groundwater moisture. Some plants from this department are used for medical purposes as dressing materials. And it is the Mokhovidny who take part in the formation of one of the minerals we are talking about peat.
The meaning of the mocking in nature can be outlined by the following functions:
In anthropological activity, mossy plants are also capable of a lot:
With all the meaning of the mocking, their practical application is so widely used: in agriculture, moss is often used for hemp from log buildings, and often moss serves as a bioindicer of the level of pollution of the surrounding space, since moss is quite sensitive to the state of nature and its pollution.
Representatives of mossy plants
The most famous representatives of mossy plants include the following species:
It is a perennial plant that grows mainly in moist territories: Kukushkin moss is distinguished by a greenish-brown tint, and a high about 20 cm.
The stalk of the plant in a spiral is decorated with small narrow leaves of green color, and is also equipped with risoids, thanks to which the plant is fixed on the soil.
This is a perennial plant a representative of white, or peat, mosses, thanks to which the deposits of this mineral are formed; sphagnum exists in swamps in conditions of moderate climate.
The sphagnum differs from the cuckoo flax in that its strongly stem is not filled with conducting bunches, and risoids are simply absent, as a result of which it absorbs water with the entire surface.
Sphagnum leaves form several types of cells:
Both types of cells are placed in one layer for this reason, sphagnum leaves look like twotone.
Cycle of Mookhovichal Plants
Mookhoid plants belong to living organisms that differ in alternating generations. In the life cycle of mosses, the sexual generation prevails, or gametophyte, which differs almost all plants. Hametophyte, together with its main purpose the formation of germ cells also carries out vegetative functions, namely, participates in the photosynthesis, the process of nutrition and water supply of the plant.
If we talk about the ash generation, or a diploid sporophyte, then during its existence it is connected to the gametophyte and is supplied with it (water, nutrition). Most mosses have small sporophytes (compared to gametophyte), which looks externally as a sporeforming organ.
In the usual case, sporgeonia is formed from the box and, as a rule, completes the full development cycle, gradually fully occupying archegony the female genital organ. If we talk about antocerot plants, then their sporenan is represented by a foot it is introduced into the gametophyte and provides nutrition, as well as a box that directly forms the disputes themselves. The box is gradually increasing due to intercaly growth, breaking through archegonia and the rest of the development of the plant is organized in open form.
Having a unicellular dispute at the start, mosses form a gametophyte from it, from which a proton is developing a kind of multicellular formation, and kidneys are laid. Such a proton is called primary, and the secondary is formed already in the process of regeneration of gametophyte cells.
Of the renal in the estrus of the kidneys, plate, or leafy shoots, which are called gametopher are created it is the genitals that are created from them. Just a proton, kidneys and gametophores in their bunch form a gametophyte of mosses.
The disputes of the moss ripen in a box a complex device covered with a special cap, and having a special vertical axis in the center, around which there is a cylindrical sporangia, fixed on special threads.
After fully maturation, the dispute in the box is leaned back, it opens into four parts and spores are spilled out. The successful process of dispersion is contributed to special elastic threads, called elater.
For the development cycle, all the mocking can be recognized as characteristic of the following points:
The process of development of the mossy starts from the moment of germination of the dispute, which, ultimately, ensures the formation of gametophytes. Disputes germinate in the form of branching seedlings in the form of singlelayer records in their vast majority, they differ significantly from adults of mossy plants.
The stage of the proton is quite fleeting several already ripened gametophytes are formed on it (though some of the mossy are distinguished by the durable stage of the proton and multiple ripening of small gametofor). Gametophores that appear from the top of the protonema (antocerotshaped or liver mosses) they form ribbon thallums, or thallus, or from the kidneys located along the protonema (leafstable mosses) here they are presented in the form of shoots.
Such shoots, as a rule, consist of stem and leaves mostly simple, but sometimes even difficult to dissected.
The habitat of mossy, as a rule, are territories with a high level of humidity the same forests or swamps. But moss can be found everywhere it dominates the mountainous and even Arctic territories, and some of the species of these plants were successfully able to adapt to inhabitation in a lifeless hot desert.
Systems of peat bogs play a special and responsible environmental role in the surrounding space it is from here that many rivers in Europe origin.
The department of the molovicular is quite diverse it is made up of several tens of thousands of plant species and all of them are very widespread on our planet. If we take moderate and cool climate (regarding the northern hemisphere), then green mosses the same Kukushkin Len, which forms loose turf in coniferous forests, are spreading here. Swamps, swampy meadows and forests with increased humidity are rich in sphagnum mosses.
Propagation of mossy plants
Propagation in mossy plants is a multivariate process: nonsex, vegetative or sexual, which was provided by moss, first of all, the ability to wide and rapid distribution.
Molovic reproduction options can be divided into several types:
A gametophyte a longterm organism with leaflike and rootlike formations, the reproduction organs in which anteriadia (spermatozoa is formed) and archegony (place of egg formation), the merger of which is the cause of the formation of diploid sporophytes, take part in this process.
And it is precisely thanks to the close connection of sporophytic and gametophyte that researchers explain the fact of group forms of formation of mossy plants.