Looking at my home cactus, I involuntarily thought: "But how did plants even begin their journey on land? And when did this happen?" I would like to talk about this very interesting topic.
How and when did the first sushi plants appear
As you know, all life on earth originated in water. And plants are no exception. Once they were all protozoan algae, but then came the stage when they began to germinate on land.
And they began their exit to the surface at the end Silura (near 4 05-440 million years ago), what in Paleozoic era. Then there were active powerful mining processes, leading to shrinkage and the drying up of many seas. This is what caused some algae to “come out” on land.
The very first plants on the surface are psilophytes. They had only a bare stem, which was attached to the ground with the help of special outgrowths - rhizoids. The psilophytes themselves had a very simple structure, but they had branching stems with outgrowths that kept disputes.
Psilophytes preferred swampy and wet area, because they did not have a powerful root system for extracting water. Today it is believed that once such plants lined endless carpets on the bare surface of the Earth.
In addition, psilophytes could be both very high(much more than human growth), and very low and tiny.
How did the first land plants adapt?
Worth a special mention fixture system, which plants have mastered for life on land. After all, they are very different from life under water. So, such difficulties could be called:
- need water conservation from its evaporation in air;
- need for education hard protective cover;
- adaptation to constant changing conditions environment.
And many others. Such plants also needed to learn how to exercise more complex photosynthesis, anchor in the soil and receive from it the necessary minerals.
All these difficulties have been overcome by plant organisms. And the evidence for this is our life on earth.
We, contemporaries, know very little about the first representatives of the plant world. Unfortunately, few of their fossils have been found. However, scientists, using fossilized prints left by ancient plants, nevertheless restored their appearance, and also examined the structural features of plants that became the first
The science that studies the features of the structure and life of fossil plants is called "paleobotany". It is paleobotanists who are looking for answers to questions about the origin of the plant world.
Classification of spore plants
The first plants on Earth reproduced with the help of spores. Among the modern representatives of the flora there are also spore plants. According to the classification, they are all combined into one group - "higher spore plants". They are represented by Rhiniophytes, Zosterophylophytes, Trimsrophytes, Psilotophytes, Bryophytes (Bryophytes), Lycopodiophytes (Lycopterous), Equizetophytes (Horsetails) and Polypodiophytes (Ferns). Among these divisions, the first three are completely extinct, while the others contain both extinct and now existing groups.
Rhiniophytes - the first land plants
The first terrestrial plants were representatives of the flora that settled the Earth about 450 million years ago. They grew near various reservoirs or in places of shallow water, which were characterized by periodic flooding and drying.
All plants that have mastered the land have a common feature. This is the division of the body into two parts - aboveground and underground. Such a structure was also characteristic of Rhyniophytes.
The remains of ancient plants were first discovered in the second half of the 19th century on the territory of modern Canada. But for unknown reasons, this find did not interest botanists. And in 1912, near the Scottish village of Rainy, a local rural doctor found several more fossilized plants. He did not know that he was holding the remains of the first terrestrial inhabitants in his hands, but, being very inquisitive, he decided to thoroughly study an interesting find. Having made a cut, he found well-preserved remains of plants. The stalk was very thin, naked, and elongated processes (similar to elongated balls) with very thick walls were attached to it. Information about the find quickly reached paleobotanists, who found out that the remains found were the first land plants. There were doubts about the name of these ancient remains. But as a result, they decided to go the simplest way and called Riniophytes after the name of the village near which they were found.
Structural features
The external structure of Rhyniophytes is very primitive. The body branched according to the dichotomous type, that is, into two parts. They did not yet have leaves and true roots. Attachment to the soil was carried out with the help of rhizoids. As for the internal structure, on the contrary, it was quite complex, especially in comparison with algae. So, it had a stomatal apparatus, with the help of which the processes of gas exchange and water evaporation were carried out. Due to their absence, the first plants on Earth were relatively small in height (no more than 50 cm) and stem diameter (about 0.5 cm).
Paleobotanists believe that all modern land plants are descended from Rhyniophytes.
Psilophytes are the first land plants. Is this true?
More likely no than yes. The name "psilophytes" actually appeared as early as 1859. It was the American paleobotanist Dawson who named one of the plants found so. He chose this option, since in translation this word means "naked plant." Until the beginning of the 20th century, Psilophytes was the name given to a genus of ancient plants. But according to the results of subsequent revisions, this genus ceased to exist, and the use of this name became unauthorized. At the moment, the most fully described genus Rinia gives the name to the entire department of the most ancient representatives of the terrestrial flora. Therefore, the first land plants were Rhyniophytes.
Typical representatives of the first land plants
Presumably, the first land plants were kuksonia and rhinia.
One of the most ancient representatives of the flora was kuksonia, which looked like a small bush no more than 7 cm high. The swamp lowlands were a favorable growing environment for it. Fossilized remains of kuksonia and related species have been found in the Czech Republic, the United States of America and in some areas of Western Siberia.
Closely related, rhinia is much better studied than cooksonia. Her body was more massive: the plant could reach a height of 50 cm, and a stem diameter of 5 mm. At the end of the stem of the rhinia was a dome in which there were spores.
The ancient representatives of the genus Rinia gave rise to many plants of the tropics and subtropics. According to the modern classification, they are united in the Psilophytes department. It is very rare, because it includes about 20 species. In some ways, they are very similar to their ancient ancestors. In particular, both of them have the approximate height of Psilophytes is from 25 to 40 cm.
Modern finds
Until recently, paleontologists have found in deposits older than 425 million years only the remains of primitive trilet spores with a smooth shell. Such finds were found in Turkey. They are attributed to the Upper Ordovician. The found specimens could not shed light on information about the time of occurrence of vascular plants, since they were single and it was completely unclear from them which particular representatives of the plant species belonged to smooth spores.
But not so long ago, reliable remains of triennial spores with an ornamented shell were found in Saudi Arabia. It was determined that the age of the found samples varies from 444 to 450 million years.
The flowering of vascular plants after the glaciation
During the second half of the Ordovician, what is now Saudi Arabia and Turkey constituted the northern part of the supercontinent, apparently, and was the original habitat of vascular plants. For a long historical period, they lived only in their "evolutionary cradle", while the planet was inhabited by representatives of primitive bryophytes with their cryptospores. Most likely, the mass settlement of vascular plants began after the great glaciation that occurred at the turn of the Ordovician and Silurian.
Telome theory
In the course of the study of Rhyniophytes, the so-called telome theory appeared, which was created by the German botanist Zimmermann. It revealed the structural features of Rhiniophytes, which by that time were recognized as the first terrestrial plants. Zimmerman also showed the alleged ways of becoming important vegetative and reproductive organs of higher plants.
According to the German scientist, the body of Rhyniophytes consisted of radially symmetrical axes, the terminal branches of which Zimmerman called telomes (from the Greek telos - "end").
Through the evolutionary path, telomes, having undergone numerous changes, became the main organs of higher plants: stems, leaves, roots, sporophylls.
So, now you can unequivocally answer the question "What were the first land plants called?". Today the answer is obvious. These were the Rhyniophytes. They were the first to get to the surface of the Earth and became the progenitors of the representatives of modern flora, despite the fact that their external and internal structure was primitive.
Most modern scientists believe that the planet Earth was formed a little earlier than four and a half billion years ago. The earliest remains of extinct organisms are found in rocks that are 3.8 billion years old. The first inhabitants of the Earth were anaerobic bacteria, that is, they did not use oxygen for breathing, which was not yet in the atmosphere.
It is believed that for the first time the process of photosynthesis began to go in bacteria. Photosynthesis is the most important natural process, when the interaction of sunlight, water and carbon dioxide produces organic matter and free oxygen.
The first protozoan unicellular algae and fungi appeared about 2 billion years ago. Their remains were found in the deposits of the Proterozoic era in Greenland and Canada. At the same time, the first multicellular plants appeared. The development of life on Earth, the appearance of both plants and animals were closely related to the process of photosynthesis.
Scientists believe that blue-green algae (this is their name, and not just a color designation) and mushrooms are the first representatives of the plant world on Earth. These are lower plants.
Over 2 billion years ago, the first land plants resembled the mosses that we can now see in damp, shady places.
Around 400,000,000 years ago, more complex plants emerged. They resembled modern ferns. Ferns were the first to have roots, stems, and leaves. These are signs of higher plants.
By the time the dinosaurs appeared, the Earth was already covered with forests. These plants reproduced by seeds.
Pines and other conifers appeared later, 300,000,000 years ago. This group of trees includes numerous representatives such as pine, spruce, Canadian spruce, cedar, larch. All these trees hide their seeds in cones.
The first flowering plants appeared 150,000,000 years ago. Their well-protected seeds gave them a great advantage over plants whose seeds are not so well protected. Therefore, there are more of them both in number and in type. These days, flowering plants are ubiquitous.
A berry is a fruit that has many seeds inside and no seeds. When the berry is ripe, it has a fleshy and juicy pericarp, like strawberries, grapes, crow's eyes, lingonberries, blueberries, blueberries, cranberries. So a cherry is not a berry, but a tomato is a berry? Yes, from the point of view of a botanical scientist, this is so. And citrus fruits: orange, lemon, tangerine, grapefruit, ...
Beech is found in forests in the temperate regions of the Northern Hemisphere. These are large trees with a height of 25-40 m and a trunk diameter of up to two meters. Smooth, like a column, the trunk is covered with gray, smooth bark. The leaves are simple, their shape is an oblong ellipse. In autumn, fruits ripen on the tree - trihedral nuts. There are usually 2, less often 4 nuts in a plush, in which ...
This plant is found only in East and Southeast Asia. Europeans knew nothing about it for a very long time, although lemongrass has been used in folk medicine in Korea, Japan and China since time immemorial. Lemongrass is an excellent tonic. It improves the tone of the body, gives a person cheerfulness. Lemongrass tincture prevents and relieves fatigue during heavy physical exertion. Lemongrass -…
At the word “mushroom”, we recall the boletus, honey mushrooms, russula and even grebes familiar to us from childhood - in a word, something consisting of a hat and a leg that grows in the forest and falls into our basket if it is edible, or which is so nice to give up foot if it looks like a toadstool. But this is, so to speak, the “traditional” form of mushrooms. At the very…
In temperate climates, the apple tree is the most important fruit tree. Scientists have counted at least 10 thousand varieties of apple trees. They were bred from various varieties of wild plants. All these varieties are adapted to different climates and soils. But the middle zone of Russia is rightfully considered the apple land, and the most famous and favorite variety of apples is amber-yellow, fragrant, sweet-sour and crunchy ...
It is absolutely impossible to imagine life without tea. This fragrant drink contains vitamins B1, B2, C, P, PP, tannin, caffeine and other useful substances. The seeds are used to extract the oil used in perfumery. Medicines are made from the waste of the leaves. The birthplace of tea is the subtropical forests of Southeast Asia, the southern regions of China, Burma, North Vietnam and the state of Assam in northeast India near ...
Bright orange nasturtiums are also called capuchins because of the pointed shape of the flower, reminiscent of the hood of a capuchin monk. At home, in tropical America, you can find up to 80 species of nasturtiums. They grow in humid tropical forests, and in arid steppes, and in the mountains. They are also painted in beautiful yellow, orange colors, but there are blue and purple nasturtiums. All tropical nasturtiums ...
Captain James Cook; visiting the islands of New Zealand, he could not help but pay attention to the plant that grew along the banks of streams and along the edges of swamps. Its leaves, very reminiscent in shape and. the size of swords, covered the coastal hills, and were found in thickets of evergreen shrubs and even in dry rocky places. It was New Zealand flax, which later became famous ...
Until now, the museums keep elegant furniture made of ebony with birch inlays - tables, armchairs, bureaus. She was especially in vogue under Peter I and until the end of the 18th century. Then, in rich houses, furniture made of “mahogany” appeared. For a long time it was considered the most precious of the decorative breeds. And still in...
Palm trees feed, water, clothe people. The most useful of them is the coconut palm. It is one of the ten most important trees in the world. The coconut palm grows in the tropics, on the shores of the oceans, seas and islands. Their high, 25-30 m trunks are usually inclined towards the sea. Almost all islands in the Pacific Ocean are occupied by groves of coconut palms. These plants are not afraid of salty ...
400 million years ago, a huge part of the earth's surface of our planet was occupied by seas and oceans. The first living organisms arose in the aquatic environment. They were pieces of slime. After several million years, these primitive microorganisms developed a green color. In appearance, they began to resemble algae.
Plants in the Carboniferous
Climatic conditions favorably influenced the growth and reproduction of algae. Over time, the surface of the earth and the bottom of the oceans were subjected to changes. New continents arose, while the old ones disappeared under water. The earth's crust was actively changing. These processes led to the fact that water appeared on the site of the earth's surface.
Retreating, sea water fell into crevices, depressions. They then dried up, then again filled with water. As a result, those algae that were on the seabed gradually moved to the earth's surface. But since the drying process was very slow, during this time they adapted to the new living conditions on earth. This process has been going on for millions of years.
The climate at that time was very humid and warm. He contributed to the transition of plants from marine to terrestrial life. Evolution led to the complication of the structure of various plants, and ancient algae also changed. They gave rise to the development of new terrestrial plants - psilophytes. In appearance, they resembled small plants that were located near the banks of river lakes. They had a stem that was covered with small bristles. But, like algae, psilophytes did not have a root system.
Plants in a new climate
Ferns originated from psilophytes. The psilophytes themselves ceased to exist 300 million years ago.
Humid climate and a large amount of water led to the rapid spread of various plants - ferns, horsetails, club mosses. The end of the Carboniferous period was marked by a change in climate: it became drier and colder. Huge ferns began to die out. The remains of dead plants rotted and turned into coal, with which people then heated their homes.
Ferns had seeds on their leaves, which were called gymnosperms. Modern pines, spruces, firs, which are called gymnosperms, originated from giant ferns.
With climate change, ancient ferns have disappeared. The cold climate destroyed their tender shoots. They were replaced by seed ferns, which are called the first gymnosperms. These plants have perfectly adapted to the new conditions of a dry and cold climate. In this plant species, the reproduction process did not depend on the water that is in the external environment.
130 million years ago, various shrubs and herbs arose on Earth, the seeds of which were in the surface of the fruit. They were called angiosperms. For 60 million years, angiosperms have lived on our planet. These plants have remained virtually unchanged from then to the present day.
400 million years ago, a huge part of the earth's surface of our planet was occupied by seas and oceans. The first living organisms arose in the aquatic environment. They were pieces of slime. After several million years, these primitive microorganisms developed a green color. In appearance, they began to resemble algae.
Climatic conditions favorably influenced the growth and reproduction of algae.
Over time, the surface of the earth and the bottom of the oceans were subjected to changes. New continents arose, while the old ones disappeared under water. The earth's crust was actively changing. These processes led to the fact that water appeared on the site of the earth's surface.
Retreating, sea water fell into crevices, depressions. They then dried up, then again filled with water. As a result, those algae that were on the seabed gradually moved to the earth's surface. But since the drying process was very slow, during this time they adapted to the new living conditions on earth. This process has been going on for millions of years.
The climate at that time was very humid and warm. He contributed to the transition of plants from marine to terrestrial life. Evolution led to the complication of the structure of various plants, and ancient algae also changed. They gave rise to the development of new terrestrial plants - psilophytes. In appearance, they resembled small plants that were located near the banks of river lakes. They had a stem that was covered with small bristles. But, like algae, psilophytes did not have a root system.
Plants in a new climate
Ferns originated from psilophytes. The psilophytes themselves ceased to exist 300 million years ago.
Humid climate and a large amount of water led to the rapid spread of various plants - ferns, horsetails, club mosses. The end of the Carboniferous period was marked by a change in climate: it became drier and colder. Huge ferns began to die out. The remains of dead plants rotted and turned into coal, with which people then heated their homes.
Ferns had seeds on their leaves, which were called gymnosperms. Modern pines, spruces, firs, which are called gymnosperms, originated from giant ferns.
With climate change, ancient ferns have disappeared.
The cold climate destroyed their tender shoots. They were replaced by seed ferns, which are called the first gymnosperms. These plants have perfectly adapted to the new conditions of a dry and cold climate. In this plant species, the reproduction process did not depend on the water that is in the external environment.
130 million years ago, various shrubs and herbs arose on Earth, the seeds of which were in the surface of the fruit. They were called angiosperms. For 60 million years, angiosperms have lived on our planet. These plants have remained virtually unchanged from then to the present day.
Without plants, our planet would be a lifeless desert. And the leaves of trees are small factories or chemical laboratories, where, under the influence of sunlight and heat, the transformation of substances takes place. Trees not only improve the composition of the air and soften its temperature. The forest has medicinal value, it also provides most of our needs for food, as well as for materials such as wood and cotton; they are also raw materials for the production of medicines.
I. What were the very first plants on earth?
Life on Earth began in the sea. Plants were the first to appear on our planet. Many of them got out on land and became completely different. But those that remained at sea remained almost unchanged. They are the most ancient ones, everything started with them. Without plants, life on Earth would not be possible. Only plants can absorb carbon dioxide and release oxygen. To do this, they use the sun's rays. Algae were among the first plants on earth.
More than 20,000 species of algae are known. They can anchor themselves to rocks or to the seafloor with a foot-like 'bracket' that transitions into a leafy branch. Brown algae grow in cold waters and reach enormous sizes. Red algae are characteristic of warm seas. Green and blue-green algae can be found in both warm and cold waters. Many useful substances are obtained from brown algae, which are used in the production of plastics, varnishes, paints, paper, and even explosives. They are used to make medicines, fertilizer, and feed for livestock. Among the peoples of Southeast Asia, algae are the basis of many dishes.
Algae "Floating forest".
In the old days, there were legends about the Sargasso Sea, where ships died, stuck in algae. But still, in some places the thickets of algae are so dense that they can delay a light boat. These are brown algae-sargasso, after which the sea itself is named. Sargassums look like bushes dotted with "berries" - air bubbles that allow the plant to stay on the surface of the water. Unlike other large algae, sargasso do not attach to the bottom and travel in huge clusters along the waves and form a floating forest. A myriad of molluscs, worms, and bryozoans attach themselves to the leaves of the sargassum, and crabs, shrimps, and fish hide in its thickets. Almost all the "residents" are brownish-yellow in color, in the tone of sargasso, and their bodies often copy the shape of the "leaves" of this algae. Some are hiding so as not to frighten off the victim. So this whole community swims, never touching the shore.
II. They feed, clothe, delight.
1. Trees that provide food.
Coffee is one of the most popular drinks in the world.
Who and how gave us this wonderful drink? According to an old Arab legend, we are obliged to find coffee. goats. One Ethiopian shepherd, the legend says, noticed that his goats, having eaten some berries from a bush, continued to graze all night, and did not think to rest. The shepherd told the wise old man about this, and he, having tasted these berries, discovered their miraculous power and invented the coffee drink.
The Ethiopians liked coffee so much that later one of the tribes, having moved to the Arabian Peninsula, took its grains with them. This was the beginning of the first coffee plantations. And it happened, as is known from ancient manuscripts, in the 9th century. Coffee for a long time was known only to the Arabs, but the Turks, who conquered in the XV-XVI centuries. part of the Arab territories, also appreciated the taste and wonderful properties of the drink. This is how the famous method of making Turkish coffee appeared: coffee is brewed on hot sand in special copper vessels with a handle - “Turks”.
Europeans were first introduced to coffee by an Italian who returned from Turkey. A doctor by profession, he recommended that his patients drink coffee for medicinal purposes. Venice was the first to import coffee to Europe. And in 1652 the first coffee house was opened in England. Turkey was the monopoly supplier of coffee to Europe, but the cunning Dutch, having stolen seedlings of coffee trees from the Turks, transported them to Indonesia, where the climate was quite suitable for growing coffee.
Brazil is now the world leader in coffee production.
Coffee came to Russia thanks to Peter the Great.
Coffee drink is brewed from processed seeds of the coffee tree. This is an evergreen plant from the madder family. White lush inflorescences of the coffee tree, located in the axils of the leaves, after pollination by insects, turn into fruits - red berries remove the pulp from them, the seeds are polished in special drums and packed in bags. Coffee beans are roasted before brewing.
The birthplace of coffee is Africa. The Arabian species is considered the highest quality and most delicious. Brazilian coffee (this is not a species, but only a place where coffee is grown), which fills all the markets of the world, is much worse in quality than coffee grown in other countries.
2. Noble friends.
Cedruses are real cedars. Phoenicia, Egypt, Assyria were powerful powers of antiquity. But the territories they occupied were deserted, there were almost no forests there. And wood is needed for the construction of housing, and for ships. The wood is strong and does not rot. The cedar that the ancients loved is not the cedar that grows in the taiga and is famous for its delicious nuts. Siberian pines are "namesakes" of real cedars - cedrus.
The Phoenicians cut Cedruses into ships, the Egyptians into sarcophagi for the funeral ceremonies of their nobles, the Greeks and Romans used cedar to build temples and make furniture. Later, the crusaders began to cut down the cedrus. And during the First World War, the most valuable cedars with their pink wood, for lack of other fuel, were burned in locomotive fireboxes. So there are only 4 groves of Lebanese cedars left. True, other types of cedar - Atlas, Cypriot and Himalayan, although very rare trees, but unlike the Lebanese cedar, are still not disappearing.
Lebanese cedars are majestic trees with powerful horizontal branches. Their needles are bluish, collected in tassels. Cones the size of a fist, dense, almost smooth, like barrels. When the seeds ripen in them, the cones do not open, but crumble, and the earth is covered with a layer of scales. The wind blows off the winged seeds from them and spreads them around. If the goats, which are bred in abundance by the locals, do not eat the young shoots, a new generation of handsome cedars may grow out of them. The fame of the beauty of the Lebanese cedars has also reached Russia. Therefore, when the Russian pioneers saw Siberian pines, tall, majestic, with large cones, they called them cedars.
Siberian cedar is an amazing pine. The main wealth of the cedar is its nuts. They contain fats, proteins, starch, vitamins B and D, and the needles contain many healing substances. Nuts contain more than 60% oil, which in many ways surpasses animal fats and is not inferior in nutritional value to meat and eggs. Under Ivan the Terrible, these nuts were exported abroad, and under Peter I, they began to prepare a healing and strengthening remedy in Russia - nut milk.
Pine nuts play a huge role in the life of animals. “Where there is no cedar,” the hunters say, “there is no sable.” Bears and chipmunks, squirrels and various birds eat nuts.
Healing and cedar resin - resin. During the Great Patriotic War, cedar balsam saved from wounds and burns. Resin is a necessary raw material for obtaining such a valuable medicine as camphor. Resin is also needed in optical technology.
Cedar wood is also valuable - pencil sticks, musical instruments, and furniture are made from it. Turpentine and other useful products are obtained from sawdust.
III. The study of the bark of a tree.
Norway maple
The maple I was watching is young. It has a tree trunk, which thickens every year, side branches form a crown, which consists of smaller branches, leaves. The tree is held in the soil by roots that absorb moisture and minerals dissolved in it. Therefore, the bottom of the tree trunk is wider.
If you smell the bark, then the smell is bitter, astringent. In spring, the smell of the bark intensifies and becomes sweetish.
There is no hollow in my tree. But I met trees with a hollow. Various birds make their homes in the hollow.
There are no lichens, mosses and mushrooms on the maple that I observe. Sometimes fungi form mushroom roots on the roots, supplying the trees with nitrogen and minerals.
On the bark of my tree there are traces left by a man: peeled bark and scratches from a knife, which over time it could heal.
IV. Why is my friend the best.
Norway maple - branch with fruits
Maple is one of the most elegant trees growing in our forests. In the spring, when the branches of the trees are not yet covered with leaves, the maple blossoms. Its yellow-green flowers, collected in an inflorescence, delight the eye. Maple is no less elegant in summer, when its crown becomes “curly”. Autumn outfit will not yield in beauty to any other plant. The tree seems to be on fire, striking with the richness of shades of crimson and green, orange and yellow. Each leaf has its own color, and each leaf is beautiful in its own way. And everyone has the same shape: rounded with 5-7 sharp protrusions, hence the name Norway maple. Maple is a good honey plant. Up to 10 kg of honey is obtained from one tree. Maple juice is very tasty. In Russia, kvass and various soft drinks were prepared from it.
The flag of Canada features a leaf of the Sugar Maple. Its sweet juice was used to make maple syrups, molasses, and even maple beer, which was very popular in the 19th century. Canada was the leader in the production of juice products. The maple leaf has become the national symbol of this country.
Maple wood was used to make musical instruments strong and light. Sports equipment is also made from maple. Pharmacists and chemists use the leaves and bark. Maple has another interesting property: it can predict the weather. From the petioles of the leaves, at the very branch, sometimes “tears” flow drop by drop - the maple seems to be crying. This is the property of maple to get rid of excess moisture. And the “tears” of maple depend on whether the air is dry or humid. The drier the air, the stronger the evaporation and vice versa. The air becomes humid when it rains. If “tears” appeared on the maple leaves, it means that in a few hours it will rain.
V. Fossil trees that have remained on the earth.
Ancient, ancient ginkgo tree! It appeared on earth as early as the time of the dinosaurs - 125 million years ago.
years ago. And since then, this plant has not changed much. Ginkgo is a beautiful tree up to 30 m high, with large fan-like leaves. The appearance of ginkgo resembles our ordinary aspen. But it was not there! Ginkgo is a gymnosperm, more closely related to spruce than to aspen, a flowering plant. In spring, “earrings” appear on the branches along with foliage. By autumn, large seeds resembling plums hang on the branches. The pulp of the seed, which looks like a fruit, is actually just the seed coat. It is edible and tastes salty. One problem - it smells like rotten meat. This is a way to attract seed dispersal animals. Ginkgo, although it survived the dinosaurs, did not survive in the wild. This tree has become a garden tree. In Japan and China, it is considered sacred - it is grown near temples. Now ginkgo appears on the streets of European cities. Ginkgo easily resists air pollution, diseases, and insects. Ginkgo leaves and wood contain substances that repel insects. Bookmarks from dried ginkgo leaves will protect old manuscripts from bookworms. And the walls covered with ginkgo shingles will not let cockroaches or bedbugs into the house.
CONCLUSION.
What can I do for all trees?
Coming to the forest, I will not kindle fires.
This can lead to fires.
I won't destroy bird nests. Birds eat insects that damage trees. I will not break branches from trees and shrubs. I will plant new seedlings in the yard and take care of them in the future.
Acid rain also causes irreparable damage: the death of crops, flora and fauna, the destruction of buildings.
The first land plants
Life originated in water. Here the first plants appeared - algae. However, at some point, land appeared, which had to be populated. Pioneers among animals were lobe-finned fish. And among plants?
What did the first plants look like?
Once upon a time, our planet was inhabited by plants that had only a stem. They were attached to the ground with special outgrowths - rhizoids. These were the first plants to reach land.
Scientists call them psilophytes. This is a Latin word. In translation, it means "naked plants." The psilophytes did look "naked". They had only branching stems with ball-shaped outgrowths in which spores were stored. They are very similar to the "alien plants" that are depicted in illustrations for fantastic stories.
Psilophytes became the first land plants, but they lived only in swampy areas, since they did not have a root, and they could not extract water and nutrients in the soil. Scientists believe that once these plants created huge carpets over the bare surface of the planet. There were both tiny plants and very large ones, taller than human growth.
How did scientists discover the first plants?
The fact that such plants once existed on our planet, scientists learned only at the beginning of the last century, in 1912, thanks to a Scottish rural doctor who was fond of geology. Exploring the soil, he discovered the remains of hitherto unknown plants, which were later named rhinia, after the name of the village in which it was first found. It is believed that it was the first terrestrial plant, from which other psilophytes originated.
Ancient plants dominated the planet for millions of years, but died out long before the appearance of man. But they left their "descendants" - they were horsetails, club mosses and ferns. Some scientists believe that the lower psilophytes became the progenitors of modern mosses.
