In the plant kingdom, you can find amazing specimens that not only captivate the eye, but also amaze with their way of life. One of the secrets of the nature of the Earth are carnivorous plants.
We all know from childhood that flowers and grass are food for animals, but it turns out that the opposite happens. Insectivores, which are also called carnivores, are a direct confirmation of this. Carnivorous plants are those living organisms that obtain some or most of their useful substances (but not energy) from the capture and consumption of animals or protozoa, usually arthropods. Carnivorous flora are adapted to grow in areas with thin fertile soil or little nitrogen, such as acid swamps and rock outcrops. Charles Darwin wrote his Insectivorous Plants, the first known treatise on carnivorous flora, in 1875. This book was a turning point in the study of these unusual representatives of the plant world.
How and what do carnivorous plants eat?
Carnivorous plants have leaves adapted to trap small animals, most commonly insects. That is why they are also called insectivores. Caught in such a flower in a "trap", an invertebrate arthropod dissolves in its digestive juice. As a result, the living organism of a predator plant receives the nutrients necessary for a full-fledged existence. It should be noted that enzymes dissolve soft tissue insect. They cannot “digest” skeletons or exoskeletons, so numerous remains of their victims accumulate inside some flowers.
Some flowers can absorb the juices of dead animals through the surface of the leaves. However, only real carnivorous representatives of the flora have the ability to receive nutrients from animals, first pulling them towards themselves in order to capture, and then digest and assimilate the nutrient juices of the caught victim. This behavior is called the carnivorous syndrome.
Five main mechanisms for catching prey have been found in predator plants, which do not depend on the plant belonging to a particular family:
- Jar-shaped containers - capture prey with a rolled leaf that contains a mixture of digestive enzymes or colonies of bacteria.
- Traps in the form of leaves covered with sticky mucus.
- Quickly collapsing leaves.
- Catchers in the form of a vacuum bubble that sucks the victim.
- Crab claw-like traps, also known as eel traps, force the prey to move toward the digestive organ with hair pointing inwards.
These traps can be active or passive, depending on whether the movement is conducive to capturing the prey.
The insectivorous flowers are relatively small in size, and the largest animal ever captured by one of these flowers turned out to be a small rat. More than 150 different types of insects are known to have been identified as prey to such plants, but also arachnids (spiders and mites), molluscs (snails and slugs), earthworms and small vertebrates (small fish, amphibians, reptiles, rodents and birds) are their potential prey.
Where do carnivorous plants grow?
Carnivorous flowers are found in almost all ecosystems, their distribution area is soil poor in nutrients and minerals. That is, acidic, without nitrogen, phosphorus and potassium. These representatives of the flora can be seen on every continent except Antarctica. Predatory plants are especially numerous in North America, Southeast Asia and Australia.
Carnivorous plants usually prefer to settle in damp places, which, moreover, should be open and sunny. They do not like competition, so you can meet them where other flowers and herbs do not do well.
Insectivorous flowers can be found in wet grasslands in the southeastern United States or in peat bogs in the north. North America and in Eurasia. Some of them grow in the still waters of ponds and ditches around the world. Others are on wet, rocky cliffs or on wet sand. Often these representatives of the flora are found in places where fires periodically occur, which also helps to reduce competition.
Many inquisitive botanists ask the question: where does Rosyanka live? Or where does the Flycatcher grow? Answering them, we note that although carnivorous plants are scattered around the world, in one place - the Green Swamp Reserve (Green Swamp), in the southeastern part of North Carolina, you can meet several representatives of the unique predatory flora at once. In particular, four species of the genus Sarracenia (Sarracenia), the same number of species of the genus Rosyanka (Drosera), ten species of the genus Pemphigus (Utricularia), three species of the genus Zhiryanka (Pinguicula) and one Venus flytrap (Dionaea) grow here at once.
Features and types of carnivorous plants
It is known that carnivorous flowers can exist without preying on insects. However, biologists believe that useful material obtained through predation help them grow faster and produce more seeds. As a result, they become more persistent and can spread to new areas. There is also a plant that only kills insects, but does not "eat" them. This is the Cape pig (Plumbago auriculata).
All carnivorous flowers are divided into:
- actively catching, with sensitive hairs and moving parts. This includes the Venus flytrap.
- passively catching, which in turn come with mucous and sticky secretions on the foliage, and with traps - bubbles, jugs, etc. Sarracenia and Nepenthes are examples here.
Many species of flora have colored leaves that are attractive to insects, and also secrete sweet nectar. In total, science knows 630 species of such insectivorous multicellular organisms, the most prominent representatives are:
- sundew- one of the largest carnivorous plants. Distributed on all continents except Antarctica. Reaches 1 meter in height and lives up to 50 years. Sticky moving tentacles serve as a trap.
- Venus flytrap- has a trap with snaps that close around the prey when it touches one of the sensitive hairs.
- zhiryanka received its greatest distribution in North and South America, Europe and Asia. Zhiryanka is characterized by rich green or pink foliage. It produces mucus that acts like glue on insects.
- pemphigus found in water bodies and in moist soil on almost all continents except Antarctica. This is the only representative of the flora, in which the bubbles serve to catch the victim.
- nepenthes grows in China, Indonesia, Malaysia, Philippines, Seychelles, India, Australia, Sumatra and Borneo. Nepenthes is a vine 10-15 meters high. It has water lily leaves to catch insects. These "vessels" contain a liquid in which the caught bugs die. The largest Nepenthes are capable of catching and absorbing even small mammals (mice, rats).
- genlisea spread in South and Central America, as well as in Africa. She is armed with a "crab claw". It is easy to get into such a “claw”, but it is almost impossible to get out because of the hairs growing at the entrance that hold the prey. Genlisea is unusual in its leaves: the above-ground foliage carries out photosynthesis, but under the soil, the underground leaves, in the form of a spiral, catch and digest the simplest microorganisms.
Carnivorous plants have long been a subject of popular interest. Representatives of the flora are featured in a number of books, films, television series and video games. These are generally fictional depictions that include exaggerated characteristics such as being huge or possessing abilities that go beyond reality, and can be seen as a kind of artistic interpretation. Two of the most famous examples of fictional carnivorous flowers in popular culture are the 1960s black comedy The Little Shop of Horrors and the triffids in John Wyndham's The Day of the Triffids.
Exist unusual plants capable of assimilating live protein foods. These are the so-called carnivorous or insectivorous plants. Habitual natural habitats of such plants are extremely poor in nutrients. These are wet rocks, raised bogs, swampy meadows, wet sands. These plants make up for the lack of nutrition by catching insects and other small animals with the help of specially adapted leaves. In most cases, insects fall into the traps, the body of which is digested by enzymes or destroyed by acids secreted for this very purpose. As a result, the plant, in addition to photosynthesis, uses an additional source of nutrition.
One of the largest species of carnivorous plants
The dimensions of the Nepenthes pitcher trap, one of the most large species insectivorous plants of the Aristolochia family, allows him to catch rats and small birds.
The genus Nepenthes (Nepenthes) includes over 70 species of plants of the Nepentaceae family,
growing mainly in tropical Asia; about 20 - on the islands of Kalimantan and Sumatra; several species in the Indochina peninsula, the Philippines, New Guinea, tropical Australia.
Most of among them are creepers reaching several meters, but there are also low shrubs. Bushy vines, as a rule, lead an epiphytic lifestyle in the warm and humid jungles of the archipelagos of the Pacific and Indian Oceans.
In tropical Asia, the Seychelles, Madagascar and Northern Australia live the most powerful of all the "predators" - representatives of the genus Nepenthes (Nepenthes). They can also grow in the mountains - at an altitude of up to 2000 m, and on the edge of the forest, and even in the surf zone. This liana most often settles on tree trunks, wrapping them around tens of meters in height and bringing narrow inflorescences to the light.
Leaves alternate, lanceolate. In addition to the usual, pitcher leaves are developed, in which rainwater accumulates. Their tip elongates into a thin long tendril that wraps around a branch of the host tree, and ends with a jug with a lid. At the base is a wide plate that supports photosynthesis. The middle part is endowed with sensitivity, enabling the plant to wrap itself around the leaves of trees. And, finally, the apical one - a jug with a lid - for catching insects.
Torone of the jug has two toothed wings from top to bottom, which serve both to support the jug and to guide crawling insects. By inner edge jug contains cells that secrete sweet nectar. Under them - a lot of hard hairs, turned downwards - a bristly palisade that does not allow the victim to get out of the jug. Wax secreted by cells smooth surface leaves in most Nepenthes, makes this surface so slippery that no claws, hooks or suckers can help the victim. Once in such a jar-trap, the insect is doomed, it sinks deeper into the water - and drowns.
Inside the jug, the proteolytic (digestive) enzyme nepentesin is secreted. Above the mouth of the jug is a fixed lid that protects the contents of the jug from rainwater and serves as a landing site for insects. Insects, crawling inside the jug, slide along its walls and end up on the bottom, where they are exposed to the action of the enzyme. Once in a liquid containing enzymes and acids, the prey is completely digested within 5-8 hours. Only the chitinous cover remains. However, Nepenthes can secrete an enzyme that can even dissolve chitin.
Where large prey gets into them: rodents, toads and even birds. The jugs are painted in bright colors: red, milky white and colored with a spotted pattern, reach 15-20, and sometimes 50 cm in length, the amount of accumulating enzyme can reach up to 1-2 liters.
And this is how Neppentes attracts those who want to drink tropical insects in the heat:
Sundew caught prey
Well, after viewing the pictures and videos, a little about each species of this plant.
In total, about 500 species of predator plants are known. In the most famous "predators" - sundews, nepenthes and sarracenia - insects make up the bulk of the prey (hence the other name for these plants is insectivorous). Others - water bladderworts and aldrovands - most often catch planktonic crustaceans. There are also such "predatory" plants that feed on fry, tadpoles, or even toads and lizards. There are three groups of such insectivorous plants - these are plants with trap leaves, in which the halves of the leaves with teeth along the edge close tightly, plants with sticky leaves, in which the hairs on the leaves secrete a sticky liquid that attracts insects, and plants in which the leaves are shaped jug with a lid filled with water.
Why do plants "predation"?
The fact is that all carnivorous plants grow on poor soils, such as peat or sand. In such conditions, there is less competition among plants (few people are able to survive here), and the ability to catch live prey, break down and assimilate animal protein makes up for the lack of mineral nutrition. Carnivorous plants are especially numerous on moist soils, swamps and swamps, where they compensate for the lack of nitrogen at the expense of caught animals. As a rule, they are brightly colored, and this attracts insects that are used to associating bright colors with the presence of nectar.
What is characteristic of carnivorous plants?
They have various devices for trapping small animals, mainly insects and arachnids, digest their victims with the "digestive juice" secreted by special glands, and absorb the resulting nutritious slurry, thus supplementing the nitrogen they need, obtained from the soil, with nitrogen from animal tissues. Leaves are usually turned into insect trapping organs. They are covered with glue, carry sticky hairs, can be bent inward, closing like a palm gathered into a fist. The leaf can be turned into a jar with a lid, from which an insect that has entered it cannot escape.
There are reasons to believe that some cultivated plants not averse to eating "meat" So, rainwater accumulates in the bases of pineapple leaves, and small aquatic organisms multiply there - ciliates, rotifers, worms, insect larvae. There are suspicions that pineapple is able to digest and assimilate them.
The most famous types:
Sundew
The genus Drosera (sundew) includes about 130 plant species. They live in tropical swamps, and in the long-drying soils of the Australian subtropics, and even beyond the Arctic Circle in the tundra. IN middle lane In Russia, you can meet round-leaved sundew. Usually sundews are caught small insects, but some species are able to catch larger prey.
The leaves of the sundew are covered with red or bright orange hairs, each of which is topped with a shiny droplet of liquid. In tropical sundews, the leaves resemble a necklace of many hundreds of dewdrop beads sparkling in the sun. But this is a deadly necklace: attracted by the shine of the droplets, the reddish color of the leaf and its smell, the insect gets stuck in the sticky surface.
The victim's desperate attempts to free himself lead to the fact that more and more neighboring hairs are leaning towards him, and in the end he is covered with sticky mucus. The insect dies. The sundew then releases an enzyme that dissolves the prey. Only the wings, chitinous cover and other hard parts remain intact. If not one insect, but two at once, sits on a leaf, then the hairs, as it were, share their duties and cope with both.
Zhiryanka
It acts almost the same as the sundew, luring insects with sticky secretions of its long, tapering leaves, collected in a rosette. Sometimes the edges of the leaves are bent inward, and the prey in such a tray is locked. Other leaf cells then secrete digestive enzymes. After the “dish” is consumed, the leaf unfolds and is ready to act again.
Venus flytrap
The genus Dionaea includes only one species, Dioneae muscipulata, better known as the Venus flytrap. This is the only plant in which the capture of insects by the rapid movement of the trap can be observed even with the naked eye. In nature, the flycatcher is found in the swamps of North and South Carolina.
In an adult plant, the maximum size of the trap is 3 cm. Depending on the season, the type of trap changes markedly. In summer, when there is a lot of prey, the trap is brightly colored (usually dark red) and reaches maximum dimensions. In winter, when there is little prey, the traps decrease in size. There are thick tooth-like spines along the edges of the leaf, each leaf (“jaw”) is equipped with 15-20 teeth, and in the middle of the leaf there are three sentinel hairs. An insect or other creature attracted by a bright leaf cannot but touch these hairs. The collapse of the trap occurs only after a double irritation of the hairs in the range from 2 to 20 seconds. This prevents the traps from triggering when it rains.
It is no longer possible to open the trap. If the leaf misses or something inedible gets into it, it will reopen in half an hour. Otherwise, it will remain closed until it has digested the prey, which can take up to several weeks. As a rule, the leaves, before dying off and being replaced by new ones, work in this way only two or three times.
Nepenthes
The genus includes about 80 plant species from tropical rainforests. Most of them are creepers reaching several meters, but there are also low shrubs. Nepenthes traps are adapted to capture very large prey. The largest Nepenthes can also catch small rodents, toads and even birds. However, their usual prey is insects.
Nepenthes catch prey in a completely different way than all other predatory plants. In their tubular leaves, shaped like pitchers, rainwater accumulates. In some, the tip of the leaf is folded like a funnel, through which water flows inward; in others, it is folded over and covers the opening, limiting the amount of incoming moisture to prevent overflow in heavy rains. On the outer side of the jug, two toothed wings run from top to bottom, which serve both to support the jug and to guide crawling insects. Along the inner edge of the jug are cells that secrete sweet nectar. Under them - a lot of hard hairs, turned downwards - a bristly palisade that does not allow the victim to get out of the jug. The wax secreted by the cells of the smooth leaf surface of most Nepenthes makes this surface so slippery that no claws, hooks or suckers can help the victim. Once in such a jar-trap, the insect is doomed, it sinks deeper into the water - and drowns. At the bottom of the jug, the insect decomposes, and its soft parts are absorbed by the plant.
Nepenthes (pitchers) are sometimes called "hunting cups", since the liquid contained in them can be drunk: on top in a jug pure water. Of course, somewhere below are the undigested solid remains of the "dinners" of the plant. But with a certain caution, they cannot be reached, and almost every jug contains a sip or two, or even a lot more water.
Sarracenia
The genus includes 9 species from the Sarraceniaceae family. All members of the family are marsh plants. The flowers are very bright. And even non-flowering sarracenia attract attention: emerald, with a dense network of raspberry veins, trap leaves flowing with sweet juice resemble fabulous flowers. Attracted by a bright trap, insects sit on the trap and die.
Darlingtonia (Darlingtonia)- a swamp plant in North America, one of the strangest in the world: it amazes with its jugs in the form of a hood of a cobra that has prepared for an attack (hence the other name - Cobra Plant). Insects are caught by the smell, and the hairs on the walls of the leaves provide only downward movement.
In Australia, you can find Giant Byblis (Byblis gigantea), completely covered with leaves with sticky hairs and glands with a very sticky substance. It is about him that rumors still circulate as a man-eating plant. According to legends, the remains of people have been found near these plants more than once. The local natives used its leaves as super glue.
domestic predators
There is an opinion that predator plants cannot be kept at home. Indeed, they most often die after a while, however, there are types of predator plants that are most suitable for indoor conditions. This is a Venus flytrap, various sundews, not large species nepenthes, tropical species of butterworts and most species of sarracenia.
Sarracenia grow beautifully in a room without much care. The soil mixture should be loose and not nutritious: washed quartz sand, chopped sphagnum and high peat (1:2:3) with the addition of pieces of charcoal. Sarracenia often suffer from waterlogging, so they need good drainage. Watering - distilled or clean snow (rain) water. The best place for them in the apartment is a window sill, best of all under a constantly ajar window, wintering at t 10-15 ° C.
The Venus flytrap is very fond of children and adults, they put their fingers in it and watch how the small soft mouth closes. The surprising fact is that the reaction rate is only one-thirtieth of a second! This plant also knows how to play the game "edible-inedible", and if the food is suitable, then the leaf will open again only after 6-10 days. But if the leaf slammed shut in vain, then after 1-2 days the flycatcher will again go hunting.
It is the Venus flytrap that is most often bred at home and begin to feed. Caught flies are also suitable, and even small pieces of ordinary meat. Therefore, if such an exotic has settled in your house, setting the meat table, do not forget to invite your green friend to him.
Why do the victims of these plants voluntarily climb into deadly traps? Cunning plants share their secrets.
The Venus flytrap closes the trap if you touch its tiny hairs twice.
A hungry fly is looking for something to profit from. Having smelled a smell similar to the aroma of nectar, she sits down on a fleshy red leaf - it seems to her that this is an ordinary flower. While the fly drinks the sweet liquid, it touches with its paw a tiny hair on the surface of the leaf, then another one ... And then walls grow around the fly. The jagged edges of the leaf close like jaws. The fly tries to escape, but the trap is tightly closed. Now, instead of nectar, the leaf secretes enzymes that dissolve the insides of the insect, gradually turning them into a sticky slurry. The fly suffered the greatest humiliation that can befall an animal: it was killed by a plant.
Tropical Nepenthes attracts insects with a sweet aroma, but as soon as the unlucky ones sit on its slippery rim, they immediately slip into its open maw.
Plants versus animals.
The swampy savanna, stretching for 140 kilometers around Wilmington (North Carolina, USA), is the only place on Earth where the Venus flytrap (Dionaea muscipula) is a native inhabitant. Other species of carnivorous plants are also found here - not so famous and not so rare, but no less amazing. For example, Nepenthes (Nepenthes) with jugs similar to champagne glasses, where insects (and sometimes larger animals) find their death. Or sundew (Drosera), clasping the victim with sticky hairs, and pemphigus (Utricularia), under aquatic plant sucking up prey like a vacuum cleaner.
Many predator plants (and there are more than 675 species) use passive traps. Zhiryanka bristles with sticky hairs that hold the insect while the digestive fluid works.
Plants that feed on animals cause us inexplicable anxiety. Probably, the fact is that such an order of things contradicts our ideas about the universe. The famous naturalist Carl Linnaeus, who in the 18th century created the system of classification of wildlife that we still use today, refused to believe that such a thing was possible. After all, if the Venus flytrap really devours insects, it violates the order of nature, instituted by God. Linnaeus believed that plants catch insects by chance, and if the unfortunate insect stops twitching, it will be released.
The Australian sundew attracts insects with dew-like droplets, and then clasps them with hairs.
Charles Darwin, on the contrary, was fascinated by the willful behavior of green predators. In 1860, shortly after the scientist first saw one of these plants (it was a sundew) on a moorland, he wrote: "The sundew interests me more than the origin of all species in the world."
The silhouettes of the caught insects, like shadow theater figures, look through the leaf of the Philippine nepenthes. The wax surface of the inner wall of the jar prevents insects from escaping, and the enzymes at its bottom extract nutrients from the victim.
Darwin spent more than one month experimenting. He planted flies on the leaves of carnivorous plants and watched them slowly compress the hairs around their prey; he even tossed pieces of raw meat and egg yolk to gluttonous plants. And he found out: in order to cause a plant reaction, the weight of a human hair is enough.
Smelling the smell of food, the cockroach looks into the jug. Insectivores, like other plants, are engaged in photosynthesis, but most of them live in swamps and other places where the soil is poor in nutrients. The nitrogen they get from feeding on their prey helps them thrive in these difficult conditions.
“It seems to me that hardly anyone has ever observed a more amazing phenomenon in the plant kingdom,” the scientist wrote. At the same time, sundews paid absolutely no attention to drops of water, even if they fell from a great height. Responding to a false alarm in the rain, Darwin reasoned, would be a big mistake for a plant - so this is not an accident, but a natural adaptation.
Most predatory plants eat some insects, while others are forced to help them in reproduction. In order not to catch a potential pollinator for dinner, the sarracenia keep the flowers away from the trapping jars - on long stems.
Subsequently, Darwin studied other types of predatory plants, and in 1875 summarized the results of his observations and experiments in the book Insectivorous Plants. He was especially fascinated by the extraordinary speed and strength of the Venus flytrap, which he called one of the most amazing plants in the world. Darwin found that when a leaf closes its edges, it temporarily turns into a "stomach" that secretes enzymes that dissolve the prey.
Their buds hang down like Chinese lanterns, luring bees into intricately constructed pollen chambers.
In the course of long observations, Charles Darwin came to the conclusion that it takes more than a week for a predatory leaf to open again. Probably, he suggested, the denticles along the edges of the leaf did not converge completely, so that very small insects could escape, and thus the plant would not have to waste energy on low-nutrient food.
Some predatory plants, such as sundew, can pollinate themselves if volunteer insects are not found.
The lightning-fast reaction of the Venus flytrap - its trap slams shut in a tenth of a second - Darwin compared with the contraction of the animal's muscles. However, plants have neither muscles nor nerve endings. How do they manage to react exactly like animals?
If the sticky hair does not grab the big fly firmly enough, the insect, however crippled, will break free. In the world of predatory plants, says William McLaughlin, curator of the US Botanical Gardens, it also happens that insects die and "hunters" remain hungry.
Plant electricity.
Today, cell and DNA biologists are beginning to understand how these plants hunt, eat, and digest food—and most importantly, how they “learned” to do it. Alexander Volkov, a plant physiologist from Oakwood University (Alabama, USA), is convinced that after many years of research, he finally managed to uncover the secret of the Venus flytrap. When an insect touches a hair on the surface of a flycatcher leaf with its paw, a tiny electrical discharge is generated. The charge accumulates in the tissue of the leaf, but it is not enough for the slamming mechanism to work - this is insurance against false alarms. But more often than not, the insect touches another hair, adding a second to the first category, and the leaf closes.
On the South African royal sundew, the largest representative of the genus, a flower blooms. The leaves of this lush plant can reach half a meter in length.
Volkov's experiments show that the discharge travels down the fluid-filled tunnels that pierce the leaf, and this causes the pores in the cell walls to open. Water rushes from the cells located on the inner surface of the leaf to those located on its outer side, and the leaf quickly changes shape: from convex to concave. Two leaves collapse and the insect is trapped.
Tiny, the size of a thimble carnivorous plant genus Cephalotus from Western Australia prefers to feast on crawling insects. With guide hairs and an alluring smell, it lures ants into its digestive bowels.
The underwater pemphigus trap is no less ingenious. It pumps water out of the bubbles, lowering the pressure in them. When a water flea or some other small creature swims by and touches the hairs on the outer surface of the bubble, its cap opens, and low pressure draws water inside, and along with it, prey. In one five hundredth of a second, the lid closes again. The vesicle cells then pump out the water, restoring the vacuum in it.
The water-filled North American hybrid tempts bees with the promise of nectar and a headband that looks like the perfect landing pad. Eating meat is not the most efficient way for a plant to provide itself with the necessary substances, but, undoubtedly, one of the most extravagant.
Many other species of predatory plants are like fly tape, grabbing their prey with sticky hairs. Pitchers resort to a different strategy: they catch insects in long leaves - jugs. In the largest, the depth of the jugs reaches a third of a meter, and they can even digest some unlucky frog or rat.
The pitcher becomes a death trap thanks to chemicals. Nepenthes rafflesiana, for example, growing in the jungles of Kalimantan, secretes nectar, on the one hand, attracting insects, and on the other, forming a slippery film on which they cannot hold on. Insects that land on the rim of the jar slide in and fall into the viscous digestive fluid. They desperately move their paws, trying to free themselves, but the liquid pulls them to the bottom.
Many carnivorous plants have special glands that secrete enzymes strong enough to penetrate the hard chitinous shell of insects and get to the nutrients hiding underneath. But the purple sarracenia, found in swamps and poor sandy soils in North America, attracts other organisms to digest food.
Sarracenia helps to function a complex food web that includes mosquito larvae, small midges, protozoa and bacteria; many of them can only live in this environment. Animals crush prey falling into a jug, and smaller organisms use the fruits of their labors. Eventually, the Sarracenia absorb the nutrients released during this feast. “Thanks to the animals in this processing chain, all reactions are accelerated,” says Nicholas Gotelli of the University of Vermont. “When the digestive cycle is over, the plant pumps oxygen into the jar so that its inhabitants have something to breathe.”
Thousands of sarracenia grow in the swamps of Harvard Forest, owned by the university of the same name, in central Massachusetts. Aaron Ellison, chief forest ecologist, is working with Gotelli to find out what evolutionary reasons led flora to develop a meat-based diet.
Predatory plants clearly benefit from eating animals: the more flies researchers feed them, the better they grow. But how exactly are sacrifices useful? From them, predators obtain nitrogen, phosphorus and other nutrients in order to produce enzymes that capture light. In other words, eating animals allows predator plants to do what all members of the flora do: grow, receiving energy from the sun.
The work of green predators is not easy. They have to spend a huge amount of energy creating devices for catching animals: enzymes, pumps, sticky hairs and other things. Sarracenia or flycatcher cannot photosynthesize much because, unlike plants with ordinary leaves, their leaves do not solar panels capable of absorbing light in large quantities. Allison and Gotelli believe that the benefits of a carnivorous life outweigh the costs of living it only if special conditions. The poor soil of swamps, for example, contains little nitrogen and phosphorus, so there predator plants have an advantage over their counterparts who extract these substances in more familiar ways. In addition, there is no lack of sun in the swamps, so even photosynthesisally inefficient predator plants capture enough light to survive.
Nature has more than once made such a compromise. By comparing the DNA of carnivorous and "ordinary" plants, scientists found that various groups predators are not evolutionarily related to each other, but appeared independently of each other in at least six cases. Some predatory plants, outwardly similar, are only distantly related. Both the tropical genus Nepenthes and the North American Sarracenia have pitcher leaves and use the same strategy to catch prey, but come from different ancestors.
Bloodthirsty, but defenseless.
Unfortunately, the very properties that allow predator plants to thrive in difficult natural conditions make them extremely sensitive to changes in environmental conditions. environment. Many swamps in North America end up with excess nitrogen from nearby agricultural land fertilization and emissions from power plants. Predatory plants are so perfectly adapted to the low nitrogen content in the soil that they cannot cope with this unexpected "gift". “In the end, they just die from overexertion,” Allison says.
Another danger comes from people. The illegal trade in predator plants is so widespread that botanists try to keep secret the places where some rare species are found. Poachers are smuggling Venus flytraps out of North Carolina by the thousands and selling them from roadside stalls. The State Department of Agriculture has for some time been marking wild specimens with safe paint, invisible in normal light but shimmering in ultraviolet light, so that inspectors, when they find these plants for sale, can quickly determine whether they come from a greenhouse or from a swamp.
Even if poaching can be stopped (which is also doubtful), predator plants will still suffer from many misfortunes. Their habitat is disappearing, making way for shopping malls and residential areas. Forest fires are not allowed to run wild, which gives other plants the opportunity to grow quickly and win the rivalry with venus flytraps.
Flies, perhaps, are happy about this. But for those who admire the astonishing ingenuity of evolution, this is a great loss.
Nature never ceases to amaze us with its mysteries and surprises. It would seem that a stalk with leaves, but also carnivorous! It turns out that there is a fairly significant category of plants that live someone else's death. These are the so-called "Plutonians" - named after the mysterious lord of death and rebirth - Pluto. More common names are "carnivorous plants" and "carnivorous plants".
These plants are further proof of the mystery of evolution. For example, in order to survive in shady damp places, the so-called epiphytes move to live on a higher and more powerful neighbor, however, without harm to him; Predatory plants, according to scientists, evolved due to the extreme lack of nitrogen in the soil.
In total, about 500 species of predator plants are known. In the most famous "predators" - sundews, nepenthes and sarracenia - insects make up the bulk of the prey (hence the other name for these plants - insectivorous). Others - water bladderworts and aldrovands - most often catch planktonic crustaceans. There are also such "predatory" plants that feed on fry, tadpoles, or even toads and lizards. There are three groups of such insectivorous plants - these are plants with trap leaves, in which the halves of the leaves with teeth along the edge close tightly, plants with sticky leaves, in which the hairs on the leaves secrete a sticky liquid that attracts insects, and plants in which the leaves are shaped jug with a lid filled with water.
Why do plants "predation"?
The fact is that all carnivorous plants grow on poor soils, such as peat or sand. In such conditions, there is less competition among plants (few people are able to survive here), and the ability to catch live prey, break down and assimilate animal protein makes up for the lack of mineral nutrition. Carnivorous plants are especially numerous on moist soils, swamps and swamps, where they compensate for the lack of nitrogen at the expense of caught animals. As a rule, they are brightly colored, and this attracts insects that are used to associating bright colors with the presence of nectar.
What is characteristic of carnivorous plants?
They have various devices for trapping small animals, mainly insects and arachnids, digest their victims with the "digestive juice" secreted by special glands, and absorb the resulting nutritious slurry, thus supplementing the nitrogen they need, obtained from the soil, with nitrogen from animal tissues. Leaves are usually turned into insect trapping organs. They are covered with glue, carry sticky hairs, can be bent inward, closing like a palm gathered into a fist. The leaf can be turned into a jar with a lid, from which an insect that has entered it cannot escape.
There is reason to believe that some cultivated plants are not averse to eating "meat". So, rainwater accumulates in the bases of pineapple leaves, and small aquatic organisms multiply there - ciliates, rotifers, worms, insect larvae. There are suspicions that pineapple is able to digest and assimilate them.
The most famous types:
Sundew
The genus Drosera (sundew) includes about 130 plant species. They live in tropical swamps, and in the long-drying soils of the Australian subtropics, and even beyond the Arctic Circle in the tundra. In central Russia, you can find round-leaved sundew. Usually sundews catch small insects, but some species are able to catch larger prey.
The leaves of the sundew are covered with red or bright orange hairs, each of which is topped with a shiny droplet of liquid. In tropical sundews, the leaves resemble a necklace of many hundreds of dewdrop beads sparkling in the sun. But this is a deadly necklace: attracted by the shine of the droplets, the reddish color of the leaf and its smell, the insect gets stuck in the sticky surface.
The victim's desperate attempts to free himself lead to the fact that more and more neighboring hairs are leaning towards him, and in the end he is covered with sticky mucus. The insect dies. The sundew then releases an enzyme that dissolves the prey. Only the wings, chitinous cover and other hard parts remain intact. If not one insect, but two at once, sits on a leaf, then the hairs, as it were, share their duties and cope with both.
Zhiryanka
It acts almost the same as the sundew, luring insects with sticky secretions of its long, tapering leaves, collected in a rosette. Sometimes the edges of the leaves are bent inward, and the prey in such a tray is locked. Other leaf cells then secrete digestive enzymes. After the "dish" is consumed, the leaf unfolds and is ready to act again.
Venus flytrap
The genus Dionaea includes only one species, Dioneae muscipulata, better known as the Venus flytrap. This is the only plant in which the capture of insects by the rapid movement of the trap can be observed even with the naked eye. In nature, the flycatcher is found in the swamps of North and South Carolina.
In an adult plant, the maximum size of the trap is 3 cm. Depending on the season, the type of trap changes markedly. In summer, when there is a lot of prey, the trap is brightly colored (usually dark red) and reaches its maximum size. In winter, when there is little prey, the traps decrease in size. Along the edges of the leaf are thick spines, similar to teeth, each leaf ("jaw") is equipped with 15-20 teeth, and in the middle of the leaf there are three sentinel hairs. An insect or other creature attracted by a bright leaf cannot but touch these hairs. The collapse of the trap occurs only after a double irritation of the hairs in the range from 2 to 20 seconds. This prevents the traps from triggering when it rains.
It is no longer possible to open the trap. If the leaf misses or something inedible gets into it, it will reopen in half an hour. Otherwise, it will remain closed until it has digested the prey, which can take up to several weeks. As a rule, the leaves, before dying off and being replaced by new ones, work in this way only two or three times.
Nepenthes
The genus includes about 80 plant species from tropical rainforests. Most of them are lianas, reaching several meters, but there are also low shrubs. Nepenthes traps are adapted to capture very large prey. The largest Nepenthes can also catch small rodents, toads and even birds. However, their usual prey is insects.
Nepenthes catch prey in a completely different way than all other predatory plants. In their tubular leaves, shaped like pitchers, rainwater accumulates. In some, the tip of the leaf is folded like a funnel, through which water flows inward; in others, it is folded over and covers the opening, limiting the amount of incoming moisture to prevent overflow in heavy rains. On the outer side of the jug, two toothed wings run from top to bottom, which serve both to support the jug and to guide crawling insects. Along the inner edge of the jug are cells that secrete sweet nectar. Beneath them are many hard hairs, turned downwards, a bristly palisade that does not allow the victim to get out of the jug. The wax secreted by the cells of the smooth leaf surface of most Nepenthes makes this surface so slippery that no claws, hooks or suckers can help the victim. Once in such a jar-trap, the insect is doomed, it sinks deeper and deeper into the water - and drowns. At the bottom of the jug, the insect decomposes, and its soft parts are absorbed by the plant.
Nepenthes (pitchers) are sometimes called "hunting cups", since the liquid contained in them can be drunk: clean water is in the top of the jug. Of course, somewhere below are the undigested solid remains of the "dinners" of the plant. But with a certain caution, they cannot be reached, and almost every jug contains a sip or two, or even a lot more water.
Sarracenia
The genus includes 9 species from the Sarraceniaceae family. All members of the family are marsh plants. The flowers are very bright. And even non-flowering sarracenia attract attention: emerald, with a dense network of raspberry veins, trap leaves flowing with sweet juice resemble fabulous flowers. Attracted by a bright trap, insects sit on the trap and die.
Darlingtonia (Darlingtonia)- a swamp plant in North America, one of the strangest in the world: it amazes with its jugs in the form of a cobra hood, preparing for an attack (hence the other name - Cobra Plant). Insects are caught by the smell, and the hairs on the walls of the leaves provide only downward movement.
In Australia you can find Byblis Giant (Byblis gigantea), completely covered with leaves with sticky hairs and glands with a very sticky substance. It is about him that rumors still circulate as a man-eating plant. According to legends, the remains of people have been found near these plants more than once. The local natives used its leaves as super glue.
domestic predators
There is an opinion that predator plants cannot be kept at home. Indeed, they most often die after a while, however, there are types of predator plants that are most suitable for indoor conditions. These are the Venus flytrap, various sundews, medium-sized species of Nepenthes, tropical species of butterflies and most species of sarracenia.
Venus flytrap is grown in coarse fibrous peat. The plant requires maximum sunlight throughout the year, and in winter, when there is not enough sunlight, the plants have to be highlighted. It is watered abundantly in the summer, it is even better to keep pots with plants a third submerged in water, using boiled or boiled water for watering. rain water. In winter, watering is reduced, but the soil is not allowed to dry out completely. Requires high humidity.
Cultivation of individual hybrid species of Nepenthes does not constitute great work, with the only caveat that for the formation of jugs they require constant high humidity. Nepenthes are grown on soil consisting of fibrous peat and sphagnum moss or on pure sphagnum moss. The main thing is that the soil is always loose and well aerated. Water these plants should be plentiful and soft water, avoiding the slightest drying.
Many representatives of sundews are very difficult to keep in room conditions. However, some tropical species of sundews are very unpretentious and can grow in aquariums with high air humidity, as their leaves are very delicate and dry out easily in a dry room atmosphere. The most suitable for growing indoors are the South African sundew Drosera alicia and the American sundew Drosera capillaris (this is the most hardy sundew).
Sarracenia grow beautifully in a room without much care. The soil mixture should be loose and not nutritious: washed quartz sand, chopped sphagnum and high peat (1:2:3) with the addition of pieces of charcoal. Sarracenia often suffer from waterlogging, so they need good drainage. Watering - distilled or clean snow (rain) water. The best place for them in the apartment is a window sill, best of all under a constantly ajar window, wintering at t 10-15 ° C.
The Venus flytrap is very fond of children and adults, they put their fingers in it and watch how the small soft mouth closes. The surprising fact is that the reaction rate is only one-thirtieth of a second! This plant also knows how to play the game "edible-inedible", and if the food is suitable, then the leaf will open again only after 6-10 days. But if the leaf slammed shut in vain, then after 1-2 days the flycatcher will again go hunting.
It is the Venus flytrap that is most often bred at home and begin to feed. Caught flies are also suitable, and even small pieces of ordinary meat. Therefore, if such an exotic has settled in your house, setting the meat table, do not forget to invite your green friend to him.
These amazing plants They are carnivorous because they catch insects and arthropods, secrete digestive juice, dissolve the prey, and in the process receive some or most of the nutrients. Almost all carnivorous plants grow in places where the soil is poor in nutrients.
Here are the most famous carnivorous plants that use different types traps to lure their prey.
1. Sarracenia
Sarracenia or North American insectivorous plant is a genus of carnivorous plants that are found in areas of the east coast of North America, in Texas, in the Great Lakes, in southeastern Canada, but most are found only in the southeastern states.
This plant uses water lily-shaped traps as a trap. The leaves of the plant have developed into a funnel with a hood-like formation that grows over the opening, preventing rainwater from entering, which can dilute the digestive juices. Insects are attracted to color, smell, and secretions like nectar at the edge of a water lily. The slippery surface and the drug that surrounds the nectar encourage insects to fall inward, where they die and are digested by protease and other enzymes.
2. Nepenthes
Nepenthes, a tropical insectivorous plant, is another species of carnivorous plant with a trap that uses water lily-shaped trapping leaves. There are about 130 species of these plants, which are widely distributed in China, Malaysia, Indonesia, the Philippines, Madagascar, Seychelles, Australia, India, Borneo and Sumatra. This plant has also earned the nickname "monkey cup" as researchers often observed monkeys drinking rainwater from them.
Most types of Nepenthes are tall vines, about 10-15 meters, with a shallow root system. Leaves are often visible from the stem, with a tendril that protrudes from the tip of the leaf and is often used for climbing. At the end of the tendril, the water lily forms a small vessel, which then expands to form a cup.
The trap contains a liquid secreted by the plant, which may have a watery or sticky texture, and in which the insects eaten by the plant drown. The bottom of the bowl contains glands that absorb and distribute nutrients. Most of the plants are small and only catch insects, but large species such as Nepenthes Rafflesiana and Nepenthes Rajah can catch small mammals such as rats.
3. Carnivorous plant Genlisea (Genlisea)
Genlisea consists of 21 species, usually grows in humid terrestrial and semi-aquatic environments and is distributed in Africa and Central and South America.
Genlisea is a small herb with yellow flowers that use a crab claw-type trap. Such traps are easy to get into, but impossible to get out of because of the small hairs that grow towards the entrance or, as in this case, forward in a spiral.
These plants have two various types leaves: photosynthetic leaves above ground and special underground leaves that lure, trap and digest small organisms such as protozoa. The underground leaves also perform the role of roots, such as water absorption and attachment, since the plant itself does not have them. These underground leaves underground form hollow tubes that look like a spiral. Small microbes get into these tubes with the help of a stream of water, but cannot get out of them. By the time they get to the exit, they will already be overcooked.
4. Darlingtonia California (Darlingtonia Californica)
darlingtonia california is the only member of the genus Darlingtonia that grows in northern California and Oregon. It grows in swamps and cold springs. running water and is considered a rare plant.
Darlingtonia leaves are bulbous in shape and form a cavity with a hole under the swollen like balloon, structure and two sharp sheets that hang down like fangs.
Unlike many carnivorous plants, it does not use trapping leaves to trap, but uses a crab claw-type trap. Once the insect is inside, they are confused by the specks of light that pass through the plant. They land in thousands of dense, fine hairs that grow inwards. Insects can follow the hairs deep into the digestive organs, but cannot go back.
5. Pemphigus (Utricularia)
Bladderwort is a genus of carnivorous plants with 220 species. They meet in fresh water or wet soil as terrestrial or aquatic species on all continents except Antarctica.
They are the only carnivorous plants that use the bubble trap. Most species have very small traps in which they can catch very small prey such as protozoa. Traps range from 0.2 mm to 1.2 cm, and larger prey, such as water fleas or tadpoles, fall into large traps.
The bubbles are under negative pressure with respect to the surrounding stop. The opening of the trap opens, sucks in the insect and surrounding water, closes the valve, and all this happens in thousandths of a second.
6. Zhiryanka (Pinguicula)
Oilwort belongs to a group of carnivorous plants that use sticky, glandular leaves to lure and digest insects. Nutrients obtained from insects supplement the soil, which is poor in minerals. There are approximately 80 species of these plants in North and South America, Europe and Asia.
The leaves of the buttercup are succulent and usually have a bright green or pink color. There are two special kind cells located on the upper side of the leaves. One is known as the peduncle and is made up of secretory cells at the top of a single stem cell. These cells produce a slimy secretion that forms visible droplets on the surface of the leaves and acts like Velcro. Other cells are called sessile glands, and they are found on the surface of the leaf, producing enzymes such as amylase, protease, and esterase, which aid in the digestive process. While many species of butterwort are carnivorous all year round, many types form a dense winter rosette that is not carnivorous. When summer comes, it blooms and has new carnivorous leaves.
7. Sundew (Drosera)
Rosyanka is one of largest births carnivorous plants, with at least 194 species. They are found on every continent except Antarctica. Sundew can form basal or vertical rosettes from 1 cm to 1 m in height and can live up to 50 years.
Sundews are characterized by moving glandular tentacles topped with sweet, sticky secretions. When an insect lands on the sticky tentacles, the plant begins to move the rest of the tentacles in the direction of the victim in order to further drive it into a trap. Once the insect is trapped, small sessile glands absorb it and the nutrients go to plant growth.
8. Byblis
Byblis or rainbow plant it is a small species of carnivorous plant native to Australia. The rainbow plant gets its name from the attractive slime that coats the leaves in the sun. Despite the fact that these plants are similar to sundews, they are not related to the latter in any way and are distinguished by zygomorphic flowers with five curved stamens.
Its leaves have a round section, and most often they are elongated and conical at the end. The surface of the leaves is completely covered with glandular hairs, which secrete a sticky mucous substance that serves as a trap for small insects that land on the leaves or tentacles of the plant.
9. Aldrovanda vesiculosa (Aldrovanda vesiculosa)
Aldrovanda vesicularis is a magnificent rootless, carnivorous aquatic plant. It usually feeds on small aquatic vertebrates using a trap trap.
The plant consists mainly of free-floating stems that reach 6-11 cm in length. Leaves-traps, 2-3 mm in size, grow in 5-9 curls in the center of the stem. The traps are attached to the petioles, which contain air that allows the plant to float. It is a fast growing plant and can reach 4-9mm per day and in some cases produce a new curl every day. While the plant grows at one end, the other end gradually dies.
The plant trap consists of two lobes that close like a trap. The holes of the trap are directed outward and covered with fine hairs that allow the trap to close around any prey that comes close enough. The trap closes in tens of milliseconds, which is one of the fastest movements in the animal kingdom.
10. Venus flytrap (Dionaea Muscipula)
Venus flytrap, perhaps the best-known carnivorous plant that feeds mainly on insects and arachnids. It is a small plant with 4-7 leaves that grow from a short underground stem.
The leaf blade is divided into two regions: flat, long, heart-shaped petioles capable of photosynthesis and a pair of terminal lobes hanging from the main vein of the leaf, which form a trap. The inner surface of these lobes contains a red pigment, and the edges secrete mucus.
Dionaea muscipula vs Caterpillar
The leaf lobes make a snapping motion, slamming shut when its sensory hairs are stimulated. The plant is so developed that it can distinguish a living stimulus from a non-living stimulus. Its leaves slam shut in 0.1 second. They are lined with cilia that are as hard as spikes and hold their prey. Once the victim is caught inner surface leaves are gradually stimulated, and the edges of the lobes grow and merge, closing the trap and creating a closed stomach, where the prey is digested.
