Pollination

What is pollination? Bloom- this is the state of plants from the beginning of the opening of flowers to the drying of their stamens and petals . During flowering, pollination of plants occurs.

Pollinationcalled the transfer of pollen from the stamens to the stigma of the pistil. If pollen is transferred from the stamens of one flower to the stigma of the pistil of another flower, then cross pollination . If pollen falls on the stigma of the pistil of the same flower, this is self-pollination .

Cross pollination. With cross-pollination, two options are possible: pollen is transferred to flowers located on the same plant, pollen is transferred to flowers of another plant. In the latter case, it must be borne in mind that pollination occurs only between individuals of the same species!

Cross-pollination can be carried out by wind, water (these plants grow in water or near water: hornwort, naiad, vallisneria, elodea ), insects, and in tropical countries also birds and bats.

Cross-pollination is biologically more appropriate, because the offspring, combining the characteristics of both parents, can better adapt to the environment. Self-pollination has its advantages: it does not depend on external conditions, and the offspring stably retains parental traits. For example, if yellow tomatoes are grown, then next year, using their seeds, you can again get the same yellow tomatoes ( tomatoes are usually self-pollinators). Most plants cross-pollinate, although there are few strictly cross-pollinated plants (e.g., rye), more often cross-pollination is combined with self-pollination, which further increases the fitness of plants for survival.

Flower pollination types: self-pollination, cross-pollination

Wind pollinated plants. Plants whose flowers are pollinated by the wind are called wind pollinated . Usually their inconspicuous flowers are collected in compact inflorescences, for example, in a complex spike, or in panicles. They produce a huge amount of small, light pollen. Wind pollinated plants often grow in large groups. Among them are herbs. (timothy grass, bluegrass, sedge) and shrubs and trees (hazel, alder, oak, poplar, birch) . Moreover, these trees and shrubs bloom at the same time as the leaves bloom (or even earlier).

In wind-pollinated plants, the stamens usually have a long filament and carry the anther outside the flower. The stigmas of the pistils are also long, "shaggy" - to catch dust particles flying in the air. These plants also have certain adaptations to ensure that pollen is not wasted, but rather falls on the stigmas of flowers of its own species. Many of them bloom by the hour: some bloom early in the morning, others in the afternoon.

Insect pollinated plants. Insects (bees, bumblebees, flies, butterflies, beetles) are attracted by sweet juice - nectar, which is secreted by special glands - nectaries. Moreover, they are located in such a way that the insect, getting to the nectaries, must touch the anthers and stigma of the pistil. Insects feed on nectar and pollen. And some (bees) even store them for the winter.

Therefore, the presence of nectaries is an important feature of an insect pollinated plant. In addition, their flowers are usually bisexual, their pollen is sticky with outgrowths on the shell to cling to the insect's body. Insects find flowers by a strong smell, by bright colors, by large flowers or inflorescences.

In a number of plants, nectar, which attracts insects, is available to many of them. So on blooming poppies, jasmine, buzulnik, nivyanika you can see bees, and bumblebees, and butterflies, and beetles.

But there are plants that have adapted to a particular pollinator. However, they may have a special structure of the flower. Carnation, with its long corolla, is pollinated only by butterflies, whose long proboscis can reach the nectar. Only bumblebees can pollinate flaxseed Snapdragon : under their weight, the lower petals of the flowers are bent and the insect, reaching the nectar, collects pollen with its shaggy body. The stigma of the pistil is located so that the pollen brought by the bumblebee from another flower must remain on it.

Flowers can smell attractive to different insects or smell particularly strong at different times of the day. Many white or light flowers smell especially strongly in the evening and at night - they are pollinated by moths. Bees are attracted to sweet, “honey” smells, and flies are often not very pleasant smells for us: many umbrella plants smell like this. (snyt, cow parsnip, kupyr) .

Scientists have conducted studies that have shown that insects see colors in a special way and each species has its own preferences. It is not for nothing that in nature all shades of red reign among daytime flowers (but in the dark red is almost indistinguishable), and blue and white are much less.

Why so many devices? In order to have a better chance that pollen will not be wasted, but will fall on the pistil of a flower of a plant of the same species.

Having studied the structure and features of the flower, we can assume which animals will pollinate it. So, fragrant tobacco flowers have a very long tube of fused petals. Therefore, only insects with a long proboscis can reach the nectar. Flowers - white color are clearly visible in the dark. They smell especially strong in the evening and at night. Pollinators - hawk moths, night butterflies, which have a proboscis up to 25 cm long.

The largest flower in the world - rafflesia - painted red with dark spots. It smells like rotten meat. But for flies there is no smell more pleasant. They pollinate this wonderful, rare flower.

Self-pollination. Majority self-pollinating plants are crops (peas, flax, oats, wheat, tomato) , although there are self-pollinating plants among the wild ones.

Some of the flowers are already pollinated in bud. If you open a pea bud, you can see that the pistil is covered with orange pollen. In flax, pollination takes place in an open flower. The flower blooms early in the morning and after a few hours the petals fall off. During the day, the air temperature rises and the filaments twist, the anthers touch the stigma, burst, and the pollen spills out on the stigma. Self-pollinating plants, including linen, can be pollinated and cross-pollinated. Conversely, under unfavorable conditions, self-pollination can occur in cross-pollinated plants.

Cross-pollinated plants in the flower have devices that prevent self-pollination: the anthers mature and shed pollen before the pistil develops; the stigma is located above the anthers; pistils and stamens can develop in different flowers and even on different plants(double).

artificial pollination. In certain cases, a person carries out artificial pollination, that is, he himself transfers pollen from the stamens to the stigma of the pistils. Artificial pollination is carried out for different purposes: to breed new varieties, to increase the yield of some plants. In calm weather, a person pollinates wind-pollinated crops. (corn), and in cold or wet weather - insect pollinated plants (sunflower) . Both wind- and insect-pollinated plants are artificially pollinated; both cross- and self-pollinated.

Interactive lesson simulator. (Complete all the tasks of the lesson)

And also bats pollinate bananas, for the same reason there are a huge number of bananas on Samal Island. Although bananas are not only pollinators, they help a lot in this process.

By the way, bats eat only sweet fruits and nothing else.

We arrived at Bat Cave at 6 pm specifically to watch them fly out, and it was very interesting picture as they circled and scattered in all directions. And the last time we were here in the afternoon, the bats were sitting quietly along the edges of the gorge. Entrance during the day before 5 o'clock is 100 pesos per person (65 rubles), and in the evening after 5 o'clock 130 pesos per person, but this is a group entrance and there should be 6 people. There were five of us and had to pay for the 6th person to be able to enter. Those. it's 780 pesos for 6 people. We called tricycle drivers with us, still paid one entrance ticket.

This is the only thing that we managed to capture on video, because. it was very dark

I would love to arrange holidays in goa I have been interested in India for a long time. There are such different reviews about it, someone says that there are almost no fruits there, and someone is delighted with this country.

1 group of ways:Biotic pollination

Zoophyllia. 1. Most often found entomophily. The evolution of pollinating insects and flowering plants was of a conjugated character => both of them have mutual adaptations, sometimes so narrow that the plant is not able to exist without its pollinator and vice versa. Entomophilous flowers are easy to distinguish, as insects are attracted to the flower: 1) color; 2) smell; 3) food (nectar and pollen). In addition, 4) some insects seek refuge in flowers at night or from rain (the temperature inside the flower is several degrees higher); 5) some chalcid wasps reproduce in flowers (blastophage wasps and figs).

Signs of entomophilous flowers:

1) brightly colored and therefore clearly visible;

2) small flowers are collected in inflorescences that are clearly visible;

3) secrete a lot of nectar;

4) have a smell;

5) not very much pollen is formed, it is sticky, large, with an uneven surface of the exine;

6) often the flower has a specific structure adapted to a particular pollinator or group of pollinators (for example, flowers with a long corolla tube are pollinated by butterflies or bumblebees).

Color. Insects navigate where the nectar is located using the color of the corolla (spots, stripes, strokes, often not visible to humans, but visible to insects, since they also see in the ultraviolet spectrum).

The color vision of insects is different from that of humans.

The color of the corolla also has geographical patterns. In the tropics, red and orange colors are more common, in mid-latitudes a lighter color of the corolla is more common.

Coloration is also related to habitat. In the forest - lighter, on the edge and open places - diverse.

Smell. Most insects, in particular Hymenoptera, prefer aromatic smells, due to essential oils(lilac, carnation, rose, etc.).

Aminoid odors due to the presence of substances with an amino group (NH 2) (elder, mountain ash, hawthorn). Such smells attract beetles, flies and some other insects.

Indoloid odors due to the substance - indole (the cadaverous smell of decaying meat). Flowers with this smell are more common in tropical forests(rafflesia, many aroids). Attract flies. The source of the smell in this case is not nectar, but special oils secreted by the petals.

Thus, the color of the perianth is a distant signal, and the smell is a near signal for pollinators.

The main groups of insect pollinators:

1) Hymenoptera (bees, bumblebees, less often - wasps);

2) Diptera (flies) - visit less specialized flowers;

3) Lepidoptera (butterflies) - diurnal (visit mainly red and yellow flowers) and nocturnal (white flowers);

4) Coleoptera (beetles) - they mainly collect pollen as a food product, often do not cross-pollinate, but self-pollinate (for example, bronze on a wild rose). Sometimes beetles can eat the ovary and ovules.

2. ornithophyllia - pollinated by birds. It is typical for tropical regions, less often for subtropics (eucalyptus, aloe, cacti, etc.).

Signs of ornithophilous flowers:

1) no smell! because birds have a weak sense of smell;

2) the color of the corolla is mostly red and orange, less often blue or purple (birds can easily distinguish these two latest colors unlike insects).

3) the nectar is weakly concentrated and there is a lot of it (unlike insect-pollinated plants).

Birds often do not sit on a flower, but pollinate it on the fly, hovering near it.

Main pollinators:

1) tropics of the New World (America) - hummingbirds;

2) the tropics of the Old World - honeysuckers, nectaries, flower girls;

3) Australia - Lori parrots.

3. Chiropterophilia Pollination by bats. This way, mainly tropical trees and shrubs are pollinated, less often - herbs (baobab, banana, some cacti).

Bats visit flowers at night. => Signs of flowers pollinated by bats:

1) fluorescent white or yellow-green color, may be brownish, less often - purple or white;

2) a specific smell, reminiscent of the secretions and secretions of bats ("stale");

3) flowers bloom in the evening or at night;

4) large flowers hang on long stalks from branches (for example, baobab) or develop directly on tree trunks (caulifloria) (for example, cocoa).

One of the plants pollinated by bats is the mango. Flowers and fruits of wild mango stink very strongly and attract bats (and as fruit distributors as well). When breeding mango cultivars, they tried to get rid of the smell of fruits. To some extent, this was successful, but the specific aftertaste still remained.

2 group of ways:abiotic pollination.

1.Anemophilia - Pollination by wind.

In the temperate forest zone, approximately 20% of plants are wind pollinated. In open spaces (in the steppe, in the desert, in the polar regions), this percentage is much higher.

Signs of anemophilous flowers:

1) the flowers are small, inconspicuous, greenish or yellowish, often without a perianth at all or a perianth in the form of scales and films;

2) small flowers are collected in many-flowered inflorescences, which increases the chances of pollination. A very characteristic inflorescence with a dangling axis, adapted to wind pollination - an earring;

3) anthers often on long filaments, swaying, hanging from the flower;

4) very large, often feathery stigmas protrude beyond the flower;

5) a lot of pollen is produced, it is small, dry, smooth, and may have additional devices that facilitate flight (for example, air sacs);

6) very often the flowers are dioecious, and the plants are monoecious or dioecious.

Wind-pollinated plants often grow in large clusters, which increases the chances of pollination (birch grove, oak forest, bamboo thickets). Many wind-pollinated trees and shrubs in our zone bloom early in spring before the leaves bloom or simultaneously with their appearance (aspen, hazel, poplar, birch, oak, etc.).

2. hydrophilia - Pollination with water. It is rare, since water is not a typical environment for flowering plants. Flowering secondarily switched to an aquatic lifestyle. In many of them, growing in water, the flowers rise above the water and are pollinated by insects (water lily) or wind (reed).

Flowers in hydrophilic plants are immersed in water, less often they float on the surface of the water (in the latter case, other methods of pollination are possible).

Signs of hydrophilic flowers:

1) usually small and inconspicuous, solitary or collected in small inflorescences;

2) flowers are often unisexual (for example, vallisneria, elodea);

3) anthers have a thin wall, are devoid of endothecium, often filamentous in shape, in some plants they are braided around the stigma and pollen immediately falls on it and quickly germinates;

4) pollen is devoid of exine (because it floats in the water column and does not need protection from drying out).

In aquatic plants, vegetative reproduction prevails over seed reproduction, since water is not a particularly favorable environment for pollination.

The ingenuity of nature knows no bounds! One of the proofs of this is the story of nectar-eating bats and plants blooming their night flowers, whose fates are closely intertwined in the forests of Central America. Our size thumb, a tiny leaf-winged bat of Kommissaris ( Glossophaga commissarisi) spends most of his life fluttering among tropical vines Mucuna and collecting the nectar of their flowers. By generously sharing the "drink of the gods", in return, the plants receive an additional pollinator. Attracting animals during the day in bright sunlight, flowers flaunt multicolored outfits, but at night, when even the brightest colors fade, nocturnal plants like Mucuna to attract the attention of bats, they resort to the help of sound.

At night, when even the brightest colors fade, nocturnal plants resort to the help of sound to attract the attention of bats.

At the biological station La Selva(Spanish for "forest") in northern Costa Rica, a tropical liana beyond a short time wove over the forest glade green roof from leaves and flowers. Reminiscent of chandeliers on the ceiling in a large dark hall, palm-sized pale yellow blooms sway slowly. At sunset, the flowers begin to prepare for the reception of guests. The light green sepal is the first to slowly move upward, covering the bud like a lid, and, having risen, turns into a beacon. A little lower, two small side petals straighten out, exposing a gap at the base of the bud, from which a barely noticeable alluring garlic aroma spreads around. Mucuna use scent as a signal to attract nearby pollinators. But after, when the mice fly close enough, the main lure is the sound. Bats successfully use high-frequency sound for orientation in space. By emitting sound waves, animals pick up the smallest changes in the signals reflected from objects with their very sensitive ears. The incoming information is instantly processed by the brain, and the bat can instantly change its flight path, chasing a succulent mosquito, or deftly snoop between flowering tropical trees. Most species of bats prey on insects, with each flap of their wings they emit signals that spread over long distances. Nectarivorous mice, on the other hand, use weaker waves, but their signals are much more complex - scientists call this trick frequency modulation. Thanks to it, animals can receive "acoustic images" containing accurate information about the size, shape, location of objects in space, and the structure of their surface. For the ability to better distinguish details, you have to pay with the range of such echolocation - it is effective only within a radius of 4 meters. In tropical thickets of Mucuna lianas, beacon sepals serve as a kind of mirror, reflecting the signals of bats and sending back clearly identifiable information about themselves. Having learned to deftly recognize such beacons with the help of their senses, bats freeze in a hot embrace with buds. Definitely they are made for each other. A bat, climbing on top of a flower, clings to the base of the petal with its paws, tightens its tail, pulls up its hind leg and sticks its head into the bud. A long tongue rushes inward, triggering the “bomb” mechanism hidden in the flower: sinking deeper and deeper into the nectar, it causes chain explosions of anther sacs that abundantly cover the animal’s fur with a golden layer of fresh pollen. Bach! Bach! Bach! Ten buds have exploded, nectar supplies have been destroyed, and the bats are on their way. But the fast metabolism of bats does not allow them to fly away for a long time. Each animal visits the flower a hundred times a night. Liana type Mucuna holtonii with their "bombs" and a generous portion of nectar, it is one of the few species that animals land on, and not just fly up. Other plants, not so rich in nectar, do not receive such an honor: nectar-eating bats hover over them, devastating them in a fraction (1/5) of a second, without landing. About 40 species of the subfamily Glossophaginae make up the "air force" elite of nectar-eating bats. They belong to the family of leaf-nosed bats that live in the tropics and subtropics of the Western Hemisphere. Their bizarre noses, which gave the name to the whole family, allow them to skillfully emit complex echolocation signals. Pollination in exchange for nectar is a deal between a plant and a bat, which biologists have dubbed the scientific term chiropterophilia (from Latin name bats - Chiroptera). For millennia, bat-pollinated plants have “figured out a very elegant way to solve the difficult problem of attracting as many pollinators as possible with as little energy as possible. Instead of increasing the amount (and improving the quality) of the nectar, they instead made it more efficient for their bat partners to collect it. Plants hang out night flowers in free spaces for passage, so it is quite easy for bats to find them and collect nectar. (It's also much safer—there's nowhere for predators like snakes and opossums to hide.) In addition, flowers mix sulfur compounds into their fragrances, a long-range lure that bats can't resist. However, the aroma is not for everyone, and on the contrary, it repels a person, resembling an imaginary mixture of the most unpleasant odors that exist in the world: it has notes of the smell of sauerkraut, garlic, rotten rotting leaves, sour milk and skunk. Mucuna and some other plants have gone a step further by adapting the shape of their flowers to attract bat sonar. Until 1999, no one could have imagined that plants could change shape to make it easier for animals to collect nectar. At the research station La Selva German biologists Dagmar and Otto von Gelversen from the University of Erlangen-Nuremberg were studying the acoustic signals of bats when Dagmar noticed that the beacon sepals of the buds Mucuna very much like sound beacons-reflectors. They attract attention in the world of sounds, like a guiding light of a beacon in the dark. The hypothesis was confirmed after a series of experiments. The Gelversens continued their study of the acoustic characteristics of flowers in Erlangen using a colony of laboratory bats. Under their guidance, student Ralph Simon trained animals to drink nectar from randomly placed feeders. different shapes. The easiest and fastest animals managed to find rounded feeders - in the form of a bowl. Subsequently, Simon found similar forms of "feeders" in nature, and one of the flowers, which he saw in a photograph in a popular science magazine, had a saucer-shaped beacon. (Because of the red, rounded nectar-containing parts of the flower, the editors of the magazine mistakenly thought it was a fruit.) Intrigued, Ralph Simon went to Cuba, straight to where the flower was photographed. As a reward for perseverance, he received confirmation of his hypothesis by seeing how bats drink nectar from a flower, and he generously covers them with his golden pollen.

The study confirmed a fact long known to bats - flowers "speak" their own languages.

Back at the lab, Simon built similar beacons and attached them to the feeders. Ordinary flat beacons did not help much to find the feeder - the search time was almost the same as for unmarked feeders. But saucer-shaped beacons cut this time in half! “A flat lobe only gives off a flash in the world of sounds when the signal bounces off its surface,” explains Simon. “But the saucer beacon, when a bat approaches, sends back several strong signals, covering a vast area. It is very similar to a real lighthouse: the reflected sound has a unique timbre.” Continuing his work in graduate school, Simon designed a mechanical bat head that could move around. Inside, he installed a small source of ultrasound and two receivers at the vertices of the triangle, exactly imitating the nose and ears of the animal. During the experiment, the source nose emitted complex sequences of sounds at different frequencies, similar to the echolocation signals of bats, and Simon directed them to flowers mounted on a rotating stand, and recorded the reflected sound waves recorded by the receiving ears. So he managed to collect the acoustic characteristics of flowers of 65 plant species pollinated by bats. Each of the flowers Simon studied had a unique, pronounced acoustic image, a kind of "fingerprint". This study confirmed a fact long known to bats - flowers "speak" their own languages. Back in the 1790s, the Italian biologist Lazzaro Spallanzani was ridiculed for suggesting that bats “see” in the dark with their ears. A century and a half later, in the late 1930s, scientists confirmed this fact by establishing exactly how and by what mechanism bats "see" in the dark. And after 75 years, scientists found out that night plants help them “see”, adjusting the shape of their flowers in the process of evolution so that they can be better heard by pollinators, and as a result, “sparkling” in the world of sounds as brightly as their sparkle in the sun. the most multicolor day counterparts.

In the temperate zones, the pollination of flowers is in most cases done by insects, and it is believed that the lion's share of this work falls on the bee. However, in the tropics, many species of trees, especially those that bloom at night, rely on bats for pollination. Scientists have proven that "bats that feed on flowers at night ... apparently play the same ecological role that hummingbirds play during the day."

The leaf-nosed bat (Leptonycteris nivalis), in search of nectar, sticks its tongue into the flower of the cereus and gets dirty in the pollen, which it then transfers to other flowers.

This phenomenon has been studied in detail in Trinidad, Java, India, Costa Rica, and many other places; observations revealed the following facts:

In Ghana, a female bat visits the inflorescences of Parkia clappertontana.

1. The smell of most flowers pollinated by bats is very unpleasant for humans. This applies primarily to the flowers of Oroxylon indicum, baobab, as well as some types of kigelia, parkia, durian, etc.

2. Bats come in different sizes - from animals smaller than a human palm to giants with a wingspan of more than a meter. The little ones, launching long red tongues into the nectar, either soar above the flower, or wrap their wings around it. Big bats stick their muzzles into the flower and begin to quickly lick the juice, but the branch sinks under their weight, and they fly up into the air.

3. Bat-attracting flowers belong almost exclusively to three families: Bignonia (Bignoniacea), Mulberry Cotton (Bombacaceae) and Mimosa (Leguminoseae). The exception is Phagrea from the Loganiaceae family and the giant cereus.

Rat "tree"

Climbing pandanus (Freycinetia arborea), found on the islands Pacific Ocean, is not a tree, but a creeper, although if its many trailing roots manage to find an appropriate support, it stands so straight that it looks like a tree. Otto Degener wrote about him:

“Freycinetia is quite widespread in the forests of the Hawaiian Islands, especially in the foothills. It is not found anywhere else, although more than thirty related species have been found on the islands located to the southwest and east.

The road from Hilo to Kilauea Crater is teeming with yeye ( Hawaiian name for climbing pandanus. - Approx. transl.), which are especially conspicuous in summer when they bloom. Some of these plants climb trees, reaching the very tops - the main stem wraps around the trunk with thin aerial roots, and the branches, bending, get out into the sun. Other individuals crawl along the ground, forming impenetrable plexuses.

The woody yellow stems of the yeye are 2-3 cm in diameter and are surrounded by scars left from fallen leaves. They produce many long adventitious aerial roots of almost the same thickness along their entire length, which not only supply the plant with nutrients, but also enable it to cling to a support. The stems branch every meter and a half, ending in bunches of thin glossy green leaves. The leaves are pointed and covered with spines along the edges and along the underside of the main vein ...

The method developed by the yeye to ensure cross-pollination is so unusual that it is worth talking about in more detail.

Freycinetia bracts are popular with field rats. Crawling along the branches of a plant, rats pollinate flowers.

During the flowering period, bracts consisting of a dozen orange-red leaves develop at the ends of some yeye branches. They are fleshy and sweet at the base. Three bright plumes stick out inside the bract. Each sultan consists of hundreds of small inflorescences, which are six combined flowers, of which only tightly fused pistils have survived. On other individuals, the same bright stipules develop, also with sultans. But these plumes do not carry pistils, but stamens in which pollen develops. Thus, the yeye, dividing into male and female individuals, completely secured themselves from the possibility of self-pollination ...

Examination of the flowering branches of these individuals shows that they are most often damaged - most of the fragrant, brightly colored fleshy leaves of the bract disappear without a trace. They are eaten by rats, which, in search of food, move from one flowering branch to another. Eating fleshy bracts, rodents stain their whiskers and hair with pollen, which then falls on the stigmas of females in the same way. Yeye is the only plant in the Hawaiian Islands (and one of the few in the world) that is pollinated by mammals. Some of its relatives are pollinated by flying foxes - fruit-eating bats that find these fleshy bracts tasty enough.

Ant trees

Some tropical trees are attacked by ants. This phenomenon is completely unknown in the temperate zone, where the ants are just harmless bugs that climb into the sugar bowl.

Throughout the rainforests there are countless ants of the most varied sizes and with the most varied habits - ferocious and gluttonous, ready to bite, sting, or in some other way destroy their enemies. They prefer to settle in trees and for this purpose choose a variety of flora certain types. Almost all of their chosen ones are united by the common name "ant trees". A study of the relationship between tropical ants and trees has shown that their union is beneficial for both parties ( For lack of space, we will not touch here on the part played by ants in the pollination of some flowers or in the dispersal of seeds, nor on the ways in which some flowers protect their pollen from ants.).

Trees shelter and often feed ants. In some cases, trees secrete lumps of nutrients, and ants eat them; in others, the ants feed on tiny insects, such as aphids, that live off the tree. In forests that are subject to periodic flooding, trees are especially important for ants, as they save their homes from flooding.

Trees undoubtedly extract some nutrients from the garbage that accumulates in ant nests - very often an air root grows into such a nest. In addition, ants protect the tree from all kinds of enemies - caterpillars, larvae, grinder bugs, other ants (leaf cutters) and even from people.

Regarding the latter, Darwin wrote:

“The protection of the foliage is provided ... by the presence of entire armies of painfully stinging ants, whose tiny size only makes them more formidable.

Belt, in his book The Naturalist in Nicaragua, gives a description and drawings of the leaves of one of the plants of the Melastomae family with swollen petioles and indicates that, in addition to small ants living on these plants in large numbers, he noticed dark-colored Aphides several times. In his opinion, these small, painfully stinging ants bring great benefits to plants, as they protect them from enemies that eat leaves - from caterpillars, slugs and even herbivorous mammals, and most importantly, from the ubiquitous sauba, that is, leaf-cutting ants, which, according to he said, they are very afraid of their small relatives.

This union of trees and ants is carried out in three ways:

1. In some ant trees, the twigs are hollow, or their core is so soft that the ants, arranging a nest, easily remove it. Ants look for a hole or a soft spot at the base of such a branch, if necessary, gnaw their way and settle inside the branch, often expanding both the inlet and the branch itself. Some trees even seem to prepare entrances for ants in advance. On thorny trees, ants sometimes settle inside the thorns.

2. Other ant trees place their tenants inside the leaves. This is done in two ways. Usually ants find or gnaw the entrance at the base of the leaf blade, where it connects to the petiole; they climb inside, pushing the top and bottom covers of the sheet apart, like two pages glued together - here's your nest. Botanists say that the leaf "invaginates", that is, it simply expands, like a paper bag, if you blow into it.

The second way of using leaves, which is observed much less often, is that ants bend the edges of the leaf, glue them together and settle inside.

3. And finally, there are ant trees that do not themselves provide dwellings for ants, but instead ants settle in those epiphytes and vines that they support. When you stumble upon an ant tree in the jungle, you usually don't waste time checking whether the ant streams are coming from the leaves of the tree itself or from its epiphyte.

Ants in the branches

Spruce detailed his introduction to ant trees in the Amazon:

“Ant nests in the thickening of the branches are in most cases on low trees with soft wood, especially at the base of the branches. In these cases, you will almost certainly find ant nests either at each node or on the tops of the shoots. These anthills are an expanded cavity inside the branch, and communication between them is sometimes carried out along passages laid inside the branch, but in the overwhelming majority of cases - through covered passages built outside.

A sprig of Cordia nodosa is a ready home for ants.

Cordia gerascantha almost always has pouches at the point of branching, in which very vicious ants live - the Brazilians call them "tachy", C. nodosa is usually inhabited by small fire ants, but sometimes tachy. Perhaps the fire ants were the first inhabitants in all cases, and the takhs are pushing them out.

All tree-like plants of the buckwheat family (Polygonaceae), Spruce continues, are affected by ants:

“The entire core of each plant, from the roots to the apical shoot, is almost completely scraped out by these insects. Ants settle in a young stem of a tree or shrub, and as it grows, releasing branch after branch, they make their moves through all its branches. These ants all seem to belong to the same genus, and their bite is extremely painful. In Brazil they are called tahi or tasiba, and in Peru they are called tangarana, and in both these countries the same name is commonly used for both the ants and the tree in which they live.

In Triplaris surinamensis, a fast-growing tree throughout the Amazon, and in T. schomburgkiana, a small tree in the upper Orinoco and Ca-siquiare, the thin, long tube-like branches are almost always perforated with many tiny holes that can be found in the stipule of almost every leaf. This is the gate from which, at a signal from the sentinels constantly walking along the trunk, a formidable garrison is ready to appear at any second - as a carefree traveler can easily see from his own experience, if, seduced by the smooth bark of a takhi tree, he decides to lean against it.

Almost all tree ants, even those that sometimes descend to the ground during the dry season and build summer anthills there, always keep the above-mentioned passages and bags as their permanent homes, and some species of ants in general all year round do not leave the trees. Perhaps the same applies to ants who build anthills on a branch of foreign materials. Apparently, some ants always live in their aerial dwellings, and the inhabitants of the tokoki (see p. 211) do not leave their tree even where they are not threatened by any floods.

Ant trees exist throughout the tropics. Among the most famous is the cecropia (Cecropia peltata) of tropical America, which is called the "trumpet tree" because the Waupa Indians make their wind pipes from its hollow stems. Ferocious Azteca ants often live inside its stems, which, as soon as the tree is swayed, run out and. pounce on the daredevil who disturbed their peace. These ants protect cecropia from leaf cutters. The internodes of the stem are hollow, but they do not communicate directly with the outside air. However, near the apex of the internode, the wall becomes thinner. A fertilized female gnaws through it and hatches her offspring inside the stem. The base of the petiole is swollen, outgrowths are formed on its inner side, which the ants feed on. As the outgrowths are eaten, new ones appear. A similar phenomenon is observed in several related species. Undoubtedly, this is a form of mutual accommodation, as evidenced by the following interesting fact: the stem of one species, which is never "ant-like", is covered with a waxy coating that prevents leaf cutters from climbing it. In these plants, the walls of the internodes do not become thinner and edible outgrowths do not appear.

In some acacias, the stipules are replaced by large spines swollen at the base. Acacia sphaerocephala has Central America ants penetrate these spines, cleanse them of internal tissues and settle there. According to J. Willis, the tree provides them with food: "Additional nectaries are found on the petioles, and edible outgrowths are found on the tips of the leaves." Willis adds that any attempt to damage the tree in any way causes the ants to pour out in masses.

The old riddle of which came first, the chicken or the egg, is repeated in the case of the Kenyan black-knotted locust (A. propanolobium), also known as the whistling thorn. The branches of this small shrub-like tree are covered with straight white thorns up to 8 cm long. Large galls form on these thorns. At first, they are soft and greenish-purple, and then harden, blacken, and ants settle in them. Dale and Greenway report: “The galls at the base of the thorns... are said to be due to ants that gnaw them from the inside. When the wind hits the holes of the Gauls, a whistle is heard, which is why the name "whistling thorn" arose. J. Salt, who examined the galls on many acacias, found no evidence that their formation was stimulated by ants; the plant forms swollen bases, and the ants use them.

Ant tree in Ceylon and southern India is Humboldtia laurifolia from the legume family. In him, cavities appear only in flowering shoots, and ants settle in them; the structure of non-flowering shoots is normal.

Considering the South American species of Duroia from the madder family, Willis notes that two of them - D. petiolaris and D. hlrsuta - have swollen stems directly under the inflorescence, and ants can enter the cavity through the cracks that appear. A third species, D. saccifera, has anthills on leaves. The entrance, located on the upper side, is protected from rain by a small valve.

Gauls on a "whistling thorn" in Africa (close-up).

Corner describes different kinds macarangi (the locals call them "mahang") - the main ant tree of Malaya:

“Their leaves are hollow, and ants live inside. They gnaw their way out in the shoot between the leaves, and in their dark galleries they keep a mass of aphids, like herds of blind cows. The aphids suck the sugary sap of the shoot, and their bodies secrete a sweetish liquid that the ants eat. In addition, the plant produces so-called "edible outgrowths", which are tiny white balls (1 mm in diameter), which consist of oily tissue - it also serves as food for ants ... In any case, ants are protected from rain ... If you cut escape, they run out and bite ... Ants penetrate young plants - winged females gnaw their way inside the shoot. They settle in plants that have not reached even half a meter in height, while the internodes are swollen and look like sausages. The voids in the shoots arise as a result of the drying of the wide core between the nodes, like in bamboos, and the ants turn individual voids into galleries, gnawing through the partitions in the nodes.

J. Baker, who studied ants on macaranga trees, discovered that it was possible to cause a war by bringing two trees inhabited by ants into contact. Apparently, the ants of each tree recognize each other by the specific smell of the nest.

Ants inside leaves

Richard Spruce points out that the parted tissues and integuments that form suitable places for the formation of ant colonies, are found mainly in some South American melastomas. The most interesting of these is the tokoka, whose numerous species and varieties grow in abundance along the banks of the Amazon. They are found mainly in those parts of the forest that are flooded during floods of rivers and lakes or during rains. Describing bags formed on leaves, he says:

“The leaves of most species have only three veins; some have five or even seven; however, the first pair of veins always departs from the main one about 2.5 cm from the base of the leaf, and the bag occupies precisely this part of it - from the first pair of lateral veins down.

Enlarged leaf (Dischidia rafflesiana) cut open. You can see the ant's nest and the roots of the creeper.

This is where the ants settle in. Spruce reported that he found only one species - Tososa planifolia - without such swellings on the leaves, and trees of this species, as he noted, grow so close to rivers that they are undoubtedly under water for several months of the year. These trees, in his opinion, “cannot serve as a permanent residence for ants, and therefore the temporary appearance of the latter would not leave any imprint on them, even if instinct did not force the ants to avoid these trees altogether. The trees of other species of Tosos, growing so far from the shore that their tops remain above the water even at the moment of its highest rise, and therefore suitable for the constant habitation of ants, always have leaves with bags and are not free from them in any of the seasons. . I know this from bitter experience, for I have had many skirmishes with these belligerent bugs when I damaged their dwellings while collecting specimens.

Normal small and invaginated (enlarged) leaves of Dischidia rafflesiana (Singapore).

Bag-like dwellings of ants also exist in the leaves of plants of other families.