The Carboniferous era following the Devonian inherited the progressive development of pteridophytes.
In the humid tropical climate that dominated the Earth at that time, forests of fern-like plants began to flourish. They were based on giant lycophytes - trees lepidodendrons, sigillary etc. These trees reached 30 m in height and had a trunk diameter of up to 2 m. At the top they were forked and bore a large number of leaves, reaching 1 m in length in some species. The palmate roots of lepidodendrons and sigillaria, also forked, were spread out in the upper layers of the soil. These lycophytes reproduced by spores. The spores matured in sporangia that developed on special leaves collected into cones. There were two types of disputes: small and large.
Small spores are called microspores, and large ones are called macrospores. Hence, sporangia are distinguished: microsporangia and macrosporangia.
By analogy with living heterosporous pteridophytes, one can think that from small spores thalli with male genital organs developed, and from large spores, thalli with female genital organs developed.
Tree-like ancestors of horsetails - calamites. Calamites are trees with shoots sharply divided into nodes and internodes (that’s why such plants are called “segmented”). Branches extend from the nodes (two or several at each node). Like the tree-moss mosses, calamites are heterosporous plants. They settled in swamps and reached a height of several meters.
The woody plants of Carboniferous forests also included tree seed ferns. They are famous for the fact that for the first time in the history of the plant world they had seeds as a reproductive organ (we will talk about this below). In all other respects, they are very similar to ordinary tree ferns, which reproduce by spores.
Ferns and vines climbed up the trees.
Numerous herbaceous ferns, various club mosses, horsetails, cuneate leaves, etc. settled in the undergrowth of coal forests.
During this era, densely planted forests formed in many areas of the Earth. These forests developed mainly on the banks of reservoirs or in swamps. They produced a huge mass of wood, which, after the plants died, remained in place, plunging into water or swampy soil, where complete decomposition of the plant mass did not occur. Developing over many millions of years, these forests produced vast amounts of buried plant material, from which much of the coal deposits(hence the era of the dominance of ferns is called Carboniferous). When mining coal deposits, one often encounters preserved trunks of lepidodendrons, sigillaria, calamites and other plants that lived over 250 million years before our time.
These fern-like plants had many advantages over the psilophytes that gave birth to them. They had well-developed root systems and crowns of leaves, which greatly increased the efficiency of their food absorption. They had a more perfectly constructed system of conducting tissues. These progressive features, acquired in the process of adaptation to the conditions of terrestrial existence, provided them with the opportunity to develop large bodies and the ability to quickly populate the territory. They, as we know, emerged completely victorious over psilophytes in the struggle for existence, supplanted the latter, and throughout the Carboniferous and the beginning of the next - Permian - eras they were the dominant form of plant life on Earth.
But their dominance, longer than that of the psilophytes, still came to an end in the Permian era. They are replaced by gymnosperms that are even more adapted to the land lifestyle. Tree-like lycophytes and horsetails are disappearing from the arena of life with amazing speed. All that remains of them are modest herbaceous forms of club mosses and horsetails, which have continued their history to the present day.
Only ferns, which did not play a particularly large role in the forests of the Carboniferous era, have survived to this day in a large number of species (Over 6 thousand species) and are still noticeable in the plant landscape of the Earth, especially in the tropics, where there are entire groves of tree ferns.
Tree horsetails
If you are familiar with swamp horsetail, mentally enlarge it by 20-30 times, and it will look like calamita (Fig. 15), a characteristic plant of the coal forest. To complete the similarity, the horsetail will need to change a few things. The trunks of the Kalamites were both thicker and much stronger. These were real trees with well-developed strong wood, the layer of which in the trunk reached 12 cm on each side. The wood of calamites was in many ways similar to the wood of Paleozoic conifers. Horsetails do not have such wood. Their leaves were also different. Horsetails have small scales sitting in a circle on the nodes; calamites have better developed leaves, although they have never been very large. The imprints of leafy branches of calamites are very decorative. However, the most important difference between horsetails and calamites is in the reproductive organs. In the former, sporangia (i.e., sacs with spores) are collected into neat cones that end the stem; the spores themselves are identical and have long threads twisted into springs. When the spores mature, the springs unwind; under such sails, spores fly downwind far from the parent plant. Most calamites apparently had spores without springs, and cones with sporangia in large numbers sat among the branches.
Like lepidodendrons, calamites never fall into the hands of a paleobotanist entirely. When the plant died, its trunk easily broke off at the nodes. The wide cavity inside the trunk quickly filled with silt or sand, which then hardened. Casts of the inside of the trunk were obtained. They are often found in Paleozoic sediments, but are usually of no use to either the geologist or the paleobotanist.
Distant relatives of calamites were small-growing herbaceous sphenophylls, which Zembnitsky successfully called “wedge-leaved” (in Greek “sphene” - wedge, “phyllon” - leaf), and this word is found in our literature. Here the leaves were short, greatly expanding towards the apex. Sphenophylls lived throughout the world in the Paleozoic and became extinct at the beginning of the Mesozoic era. Among them, forms with hooks on the stems were found. It is believed that some Sphenophylls were climbing plants.
Most of the materials in our today's issue are devoted to horses. How can plants be connected to a horse? Of course, many of them serve as food for horses. Remember the “horse name” of Ovsov? But a reminder of horses is also contained in some of the names of the plants themselves. We will focus on them.
Horsetail- a plant that looks like a stiff horse’s tail, the ancient Romans called it equisetum: in Latin equius- a horse, and saeta, seta– stubble, coarse hair. The English are even more specific on this issue: “horse” - “horse”, “tail” - tail, “horsetail” - horsetail. And the Russian “horsetail”, apparently, is connected with the same horse’s “tail”. Modern horsetails, unlike their Paleozoic ancestors, are predominantly small herbaceous plants. But some species still look impressive today. Giant horsetail ( equisetum giganteum) from South America reaches a height of more than 2 m, and the stem of horsetail polychaete ( Equisetum myriochaetum), native to Central America, can stretch even 10 m! True, its thickness is small - only 0.5–2 cm, so it is not easy to estimate the gigantic size of the polychaete horsetail - it spreads, resting, like vines, on other plants.
The chemical composition of different horsetails is not the same, and besides, it can change at different times of the year. Swamp and field horsetails, when found in significant quantities in hay, can cause a serious disease, equisetosis, or connecting rod, in horses. But branched and wintering horsetails are not so dangerous and are readily eaten by animals in autumn and early spring. Horsetails are widely known as medicinal plants. A decoction and liquid extract of horsetail are sometimes used as a diuretic, as well as for heart and other diseases accompanied by congestion. In Europe and North America, the tough stems of horsetails were used instead of sandpaper. Field and forest horsetails dyed wool gray-yellow*.
(Rumex confertus) is a plant belonging to the same genus of the buckwheat family as the common, sour sorrel ( Rumex acetosa). Horse sorrel differs from ordinary sorrel primarily in size - its height during flowering reaches one and a half meters. The taste of horse sorrel is not sour, but astringent.
Large paniculate inflorescences of horse sorrel can be found in damp places and as a weed throughout our country. Despite the “horse” name, animals practically do not eat this plant. Horse sorrel is used in medicine as an antiscorbutic, anthelmintic, choleretic and vascular strengthening agent. In large doses, its drugs have a laxative effect, and in small doses they have a fixative and choleretic effect. In addition, yellow dye was extracted from the roots of horse sorrel to dye wool.
Fava or broad beans (Faba vulgaris) is called one of the oldest cultivated plants - in the Mediterranean and North Africa it was cultivated as early as 2 thousand years BC. Despite the “dubious” name, not fully ripened bean seeds, containing up to 35% protein, were and continue to be widely used for human food. They are boiled, stewed, and made into soup. They are also fed to livestock, and silage from the protein-rich green mass of beans is also used to feed animals.
Beans are a fairly large plant, reaching up to 2 m in height, with a thick, hollow inside stem.
About 25 species of trees with very decorative palmate leaves are known under this name. The most famous of the horse chestnuts is the common horse chestnut ( Aesculus hippocastanum), growing wild in the camps of the Balkan Peninsula. In many European countries, horse chestnut is cultivated as a magnificent ornamental tree in parks and squares. Horse chestnut is especially good in the spring, during flowering, when the tree is covered with a huge number of large white “candles” - cone-shaped, upward-pointing paniculate inflorescences. The complex leaves of horse chestnut, consisting of 5–7 palmate segments, are also very beautiful. There are a number of decorative forms of horse chestnut - with double flowers, with variegated leaves, with round or pyramidal crowns.
The fruits of the horse chestnut are very similar to the fruits of the edible chestnut ( Castanea sativa), but, unlike the latter, along with a large amount of starch they contain poisonous saponins, which is why they become inedible. It should be noted that these two trees are representatives of different families: chestnut is from the beech family, and horse chestnut is from a separate horse chestnut family.
And its name - hippocastanum- received horse chestnut at the end of the 16th century. At that time, its seeds were used to treat the respiratory system of horses. In addition, the scar on the spiky capsule covering the hard seed resembles a horseshoe in shape - you can even discern “nail holes” on it.
* For more information about horsetails, see “Biology”, No. 16/2001
After the Devonian period came the Carboniferous, or carbon . At this time, a new attack of the sea on land began. The surface of the Earth has already been significantly smoothed after the destruction of the Caledonian mountains, which appeared in the second half of the Silurian and Devonian. The current territory of Moscow and surrounding areas was flooded by the sea. Huge swampy lowlands formed on the northern continents. In the humid, hot climate, lush terrestrial vegetation began to quickly develop, and numerous amphibians began to develop among animals.
If you and I found ourselves in a forest of the Carboniferous period, it would hardly make a pleasant impression on us. Huge trees 30-40 meters high with spreading crowns above created eternal twilight in the forest with impenetrable marshy swamps that emitted heavy fumes. Silence reigned everywhere, occasionally broken by the splashing of creatures in the water that resembled salamanders in appearance, but were many times larger than them. These are the familiar stegocephals. Most of them spent time in the water, where they caught fish - their main food.
The stegocephals crawling ashore moved with difficulty, bending and dragging their bodies along the ground. Some stegocephalians had swim membranes between their toes on their paws. On the head and body, like fish, there were lateral line organs - original locators (receivers), with the help of which fish determine the location of solid objects under water, approaching them, as well as the direction and strength of the current.
Sometimes huge predatory dragonflies, reaching 75 cm in wingspan, flew in the air; huge cockroaches, scorpions, long-legged spiders, related to modern haymakers, crawled in the darkness of the forest thickets.
The huge trees that grew in the forests of the Carboniferous period belonged to mosses, horsetails and ferns. All these plants are fern-like plants that reproduce by spores.
Thick trunks of club mosses (up to 2 m in diameter) were covered with leaf cushions with scars from fallen leaves. Leaves, sometimes reaching enormous lengths (up to 1 m), were preserved in the upper part of the trunk and its branches.
In one of the mosses, the leaf cushions looked like rhombic scales arranged in oblique rows. This plant is called lepidodendron, which means “scaly tree.” Another genus of giant clubmosses, Sigillaria, which means “seal tree,” is characterized by the fact that the scars from fallen leaves on its trunk resemble the mark of a seal. They are arranged in straight longitudinal rows. Sigillaria and lepidodendrons did not have real roots, but peculiar underground root formations of palmate shape, called stigmaria (from the Greek word “stigma” - scar, meaning scars from fallen outgrowths that played the role of roots). The second group of tree-like plants consisted of horsetails - calamites, which were inferior in height to the club mosses by about 2 times. Calamites differed from mosses in that their branches did not extend evenly from the trunk, but only in certain places - nodes that separated bare internodes. From each node (and in some species only from a part of the nodes, with alternation), a crown, or “whorl”, consisting of two or several branches, emerged. At the nodes of the articulated branches there were whorls of leaves, like modern horsetails.
Tree-like horsetails, mosses and ferns are characteristic of the tropical zone of that time, stretching from North America to Europe and further to Central Asia and Indonesia.
Along with tree-like horsetails, mosses and ferns, there were quite a lot of herbaceous representatives of these plants in the forests of the Carboniferous period. In addition, seed ferns, tree ferns, which appeared in the Devonian, were widespread. gymnosperms plants with fern-like leaves. Seed ferns were the first plants to have seeds. Of the gymnosperms, we should also note the cordaptae, which occupy a sort of intermediate place between seed ferns and conifers. These were large trees with huge, long leaves, common in both tropical and temperate zones.
In the Middle Carboniferous era, the first coniferous trees of the Walchia genus appeared. Thus, the Carboniferous period is a time of lush development of tree flora, in which tree-like spore plants predominate and ancient gymnosperms are quite richly represented.
At the same time, this is the time of formation of numerous deposits. Fossil coal was formed from woody peat that accumulated in vast forested swamps. During the Carboniferous period, deposits of the Donetsk and Moscow Region coal basins, the Urals, Central Europe and many others arose.
In the sea, due to its wide distribution, some renewal of the fauna took place. Among the simplest animals, large rhizomes appeared - foraminifera. Their body consisted of only one cell, but the shell in which this cell was located was usually multi-chambered and in some forms, for example in fusulins, reached the size of a wheat grain or more. For single-celled animals, usually microscopically small, these are very large sizes, although some foraminifera of a later time - the Paleogene - were even larger.
In the seas of the Carboniferous period, echinoderms (sea lilies and sea urchins), various brachiopods, bryozoans and other groups of animals were widespread.
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HORSEtail, PUSHER - Equisetum arvense (L.)HORSEtail - EQUISETACEAE
The genus name is derived from Latin words equius- horse and seta- tail. Spore-bearing stems of horsetail appear early in spring; they are brownish or reddish, juicy, unbranched, about 20 cm high, bearing one spore-bearing spikelet at the top. The spore-bearing ear consists of corymbose leaves sitting on short stalks; on their underside there are sporangia with spores. After the round greenish spores ripen, the stems die. Instead, summer branchy green vegetative shoots up to 50-60 cm high develop. They do not have spore-bearing spikelets, are rigid, ribbed, segmented, with whorled branches. The branches are articulated, directed upward, 4-5 ribbed. The leaves are underdeveloped; instead, there are tubular toothed sheaths. The teeth of the sheaths on the stems are triangular-lanceolate, black and white, fused in 2-3 groups, on the branches they are green, membranous, long-pointed.
Horsetail is found in crops, fallow fields, and meadows. His dwelling is like
Food, medicinal, dyeing plant.
Horsetail in the aerial part contains the saponin equisetonin, alkaloids - nicotine, equisetin; flavonoids equisetrin, isoquercitrin; soluble silicic acid, oxalic, malic and tannic acids; proteins, fatty oils, bitters, mineral salts, resins, carotene and vitamin C.
The stem and leaves contain 7-10% silica, they are rough and coarse, making horsetail practically unsuitable as green fodder and hay.
Horsetails have been known as medicinal plants for a very long time. But in modern therapy only
Equisetum arvense- horsetail. Horsetail - Equisetum sylvaticum (L.) Perennial plant 15-60cm high. The stem is erect, round, thin, segmented, with a cavity inside, grooved on the outside. Spring (spore-bearing) stems are initially light, but later, after the spores ripen, they acquire a green color. Summer stems are sterile. The spores ripen in April and May. Grows in damp, shaded places, near water bodies, in alder forests, damp deciduous and coniferous forests. Riverside horsetail, marsh horsetail - Equisetum fluviatile (L.) Em Ehrh. Perennial plant 30-150cm high. Spore-bearing and sterile stems are identical, green, thick, smooth, with 9-20 noticeable ribs, more or less unbranched. The spore-bearing spikelet is blunt, 1-2 cm long. with a thick short leg. Spores ripen from May to July. It grows along the banks of stagnant waters, and is less common in running waters, on damp, alluvial or swampy-peaty soils. Large horsetail - Equisetum telmateia Ehrh Perennial marsh horsetail with two types of stems. Barren (summer) stem 50-120 cm high, symmetrically branched, ivory-colored, slightly ribbed. The fruiting (spring) stem is 15-5 cm high, ivory-colored (brown during drought). After the spores mature, the spring stem dies. The spores ripen in April and May. Grows in damp and damp places, along the banks of streams and in ditches.
Signs of poisoning:
When poisoned, the pupils dilate and paralysis may occur. Medicinal poisonous plant.Poisoning occurs with an overdose.
In large quantities, stems and leaves in forage cause paralysis, especially in horses.
Treatment:
Application:
For medicinal purposes, only barren summer vegetative shoots of horsetail are used. They can be collected in July - August, only in dry weather, cutting them at a height of about 5 cm from the soil surface. Horsetail accelerates and enhances diuresis, has a hemostatic and anti-inflammatory effect.The diuretic effect of horsetail is stronger than that of diuretin and diuretic tea. More effective for cardiac edema, less effective for chronic nephritis.
Horsetail promotes the release of lead from the body, so it is used for this poisoning.
Good results have been obtained in the treatment of initial forms of tuberculosis. It is also used for dropsy and internal bleeding, and for hypertension.
It is contraindicated in acute nephritis.
Externally used for aphthous and ulcerative stomatitis, for skin diseases (eczema, ringworm, furunculosis) in the form of lotions and compresses.
Purulent wounds and fistulas are washed with a decoction of the herb.
Used for cleaning metal utensils, polishing wood and horn products to a shine.