Bats and angiosperms. Pollination of flowers by bats

The ultimate task of a typical flower is the formation of fruits and seeds. This requires two processes. The first is . After this, fertilization itself occurs - fruits and seeds appear. Let's consider further what exist.

General information

Plant pollination - stage, on which small grains are transferred from the stamens to the stigma. It is closely related to another stage of crop development - the formation of the reproductive organ. Scientists have established two types of pollination: allogamy and autogamy. In this case, the first can be carried out in two ways: geitonogamy and xenogamy.

Characteristics

Autogamy - by transferring grains from the stamens to the stigma of one reproductive organ. In other words, one system independently carries out the necessary process. Allogamy is the cross transfer of grains from the stamens of one organ to the stigma of another. Geitonogamy involves pollination between flowers of the same flower, while xenogamy involves pollination between flowers of different individuals. The first is genetically similar to autogamy. In this case, only recombination of gametes takes place in one individual. As a rule, such pollination is typical for multi-flowered inflorescences.

Xenogamy is considered the most favorable in its genetic effect. This pollination of flowering plants helps to increase the possibilities of recombination of genetic data. This, in turn, ensures an increase in intraspecific diversity and subsequent adaptive evolution. Meanwhile, autogamy is of no small importance for the stabilization of species characteristics.

Methods

The method of pollination depends on the grain transfer agents and the structure of the flower. Allogamy and autogamy can be carried out using the same factors. They are, in particular, wind, animals, humans, and water. The greatest variety of methods differs in allogamy. The following groups are distinguished:

Biological - carried out with the help of living organisms. There are several subgroups within this group. Classification is carried out depending on the vector. Thus, it is carried out (entomophily), by birds (ornithophily), bats(chiropterophilia). There are other methods - with the help of mollusks, mammals, etc. However, they are detected in nature quite rarely.
Abiotic - associated with the influence of non-biological factors. In this group, grain transport is distinguished by wind (anemophily) and water (hydrophily).

The ways in which it is carried out are considered adaptations to specific environmental conditions. In genetic terms, they are less important than types.

Adaptation of plants to pollination

Let's consider the first group of methods. In nature, as a rule, entomophily occurs. The evolution of plants and pollen carriers took place in parallel. Entomophilous individuals are easily distinguished from others. Plants and vectors have mutual adaptations. In some cases, they are so narrow that the culture is not able to exist independently without its agent (or vice versa). Insects are attracted to:

Color.
Food.
Smell.

In addition, some insects use flowers as a refuge. For example, they hide there at night. The temperature in the flower is higher than that external environment, by a few degrees. There are insects that reproduce themselves in crops. For example, chalcid wasps use flowers for this.

Ornithophilia

Bird pollination occurs primarily in tropical areas. In rare cases, ornithophilia occurs in the subtropics. Signs of flowers that attract birds include:

No smell. Birds have a rather weak sense of smell.
The corolla is mostly orange or red in color. In rare cases, a blue or purple color is noted. It is worth saying that birds easily distinguish these colors.
A large amount of weakly concentrated nectar.

Birds often do not land on a flower, but pollinate by hovering next to it.

Chiropterophilia

Bats pollinate mainly tropical shrubs and trees. In rare cases, they are involved in the transfer of grains to herbs. Bats pollinate flowers at night. Signs of crops that attract these animals include:

Presence of fluorescent white or yellow-green color. It can also be brownish, or in rare cases purple.
The presence of a specific odor. It resembles the secretions and secretions of mice.
The flowers bloom at night or in the evening.
Large parts hang from branches on long stalks (baobab) or develop directly on the trunks

Anemophilia

Pollination of approximately 20% of temperate plants is carried out by wind. In open areas (steppes, deserts, polar territories) this figure is much higher. Anemophilic cultures have the following characteristics:

Anemophilous cultures often form large clusters. This greatly increases the chances of pollination. Examples include birch groves, oak forests, bamboo thickets.

Hydrophilia

Such pollination is quite rare in nature. This is due to the fact that water is not a common habitat for crops. Many are located above the surface and are pollinated mainly by insects or with the help of the wind. The characteristics of hydrophilic crops include:

Autogamy

75% of plants have bisexual flowers. This ensures independent transfer of grains without external carriers. Autogamy is often accidental. This occurs especially under unfavorable conditions for vectors.

Autogamy is based on the principle “independent pollination is better than no pollination at all.” This type of grain transfer is known in many crops. As a rule, they develop in unfavorable conditions, in areas where it is very cold (tundra, mountains) or very hot (desert) and there are no vectors.

In nature, however, regular autogamy also occurs. It is constant and extremely important for cultures. For example, plants such as peas, peanuts, wheat, flax, cotton and others self-pollinate.

Subtypes

Autogamy can be:

Cleistogamy is found in different systematic groups crops (in some cereals, for example).

Birds, elephants and turtles

The relationship between trees and animals is most often expressed in that birds, monkeys, deer, sheep, cattle, pigs, etc., contribute to the dispersal of seeds, but we will consider only the effect of the digestive juices of animals on ingested seeds.

Florida homeowners have a strong dislike for the Brazilian pepper tree (Schinus terebinthifolius), a beautiful evergreen that in December bursts with red berries peeking out from the dark green, fragrant leaves in such numbers that it resembles holly. The trees remain in this magnificent decoration for several weeks. The seeds ripen and fall to the ground, but young shoots never appear under the tree.

Arriving in large flocks, red-throated blackbirds descend on pepper trees and fill their full crops with tiny berries. Then they flutter onto the lawns and walk there among the sprinklers. In the spring they fly north, leaving numerous Business Cards, and a few weeks later pepper trees begin to sprout everywhere - and especially in the flower beds where the blackbirds were looking for worms. A tired gardener is forced to pull out thousands of sprouts to prevent pepper trees from taking over the entire garden. The stomach juices of the red-throated blackbirds were somehow affecting the seeds.

Previously in the United States, all pencils were made from juniper wood (Juniperus silicicola), which grew abundantly on the plains of the Atlantic coast from Virginia to Georgia. Soon the insatiable demands of industry led to the extermination of all big trees and had to look for another source of wood. True, the few remaining young junipers reached maturity and began to bear seeds, but not a single shoot appeared under these trees, which in America are still called “pencil cedars” to this day.

But driving along rural roads in South and North Carolina reveals millions of pencil cedars, growing in straight rows along wire fences where their seeds have been dropped in the excrement of tens of thousands of sparrows and prairie birds. Without the help of feathered intermediaries, juniper forests would forever remain just a fragrant memory.

This service that birds provided for the juniper makes us wonder: to what extent do animal digestive processes affect plant seeds? A. Kerner found that most seeds, having passed through the digestive tract of animals, lose their viability. Rossler has 40,025 seeds different plants, fed to Californian buntings, only 7 germinated.

On Galapagos Islands at west coast South America grows a large, long-lived perennial tomato (Lуcopersicum esculentum var. minor), which is of particular interest, since careful scientific experiments have shown that less than one percent of its seeds germinate naturally. But in the event that the ripe fruits were eaten by giant turtles that live on the island and remained in their digestive organs two to three weeks or longer, 80% of the seeds sprouted. Experiments have suggested that the giant tortoise is a very important natural agent, not only because it stimulates seed germination, but also because it ensures their effective dispersal. Scientists, in addition, came to the conclusion that seed germination was explained not by mechanical, but by enzymatic effects on the seeds as they passed through the turtle’s digestive tract.

In Ghana Baker ( Herbert J. Baker is director of the University of California Botanical Garden (Berkeley).) experimented with the germination of baobab and sausage tree seeds. He discovered that these seeds practically did not germinate without special treatment, while numerous young shoots were found on rocky slopes at a considerable distance from adult trees. These places served as the favorite habitat of baboons, and the fruit cores indicated that they were included in the diet of the monkeys. The strong jaws of baboons allow them to easily chew the very hard fruits of these trees; since the fruits do not open themselves, without such help the seeds would not have the opportunity to disperse. The germination rate of seeds extracted from baboon excrement was noticeably higher.

In Southern Rhodesia there grows a large beautiful tree, Ricinodendron rautanenii, which is also called the “Zambez almond” and “Munketti nut”. It bears fruit the size of a plum, with a thin layer of pulp surrounding very hard nuts - "edible if you can crack them," as one forester wrote. The wood of this tree is only slightly heavier than balsa (see Chapter 15). The packet of seeds they sent me said: “Collected from elephant droppings.” Naturally These seeds rarely germinate, but there are a lot of young shoots, since elephants have a passion for these fruits. Passage through the digestive tract of an elephant does not appear to have any mechanical effect on the nuts, although the surface of the samples sent to me was covered with grooves, as if made by the tip of a sharpened pencil. Perhaps these are traces of the action of the elephant's gastric juice?

C. Taylor wrote to me that the ricinodendron growing in Ghana bears seeds which germinate very easily. However, he adds that the musanga seeds may "need to pass through the digestive tract of some animal, since in nurseries it is extremely difficult to get them to germinate, but in natural conditions the tree reproduces very well."

Although elephants in Southern Rhodesia cause great damage to savannah forests, they also provide the spread of certain plants. Elephants really like camel thorn beans and eat them in large quantities. The seeds come out undigested. During the rainy season, dung beetles bury elephant dung. This way, most of the seeds end up in a great seed bed. This is how thick-skinned giants at least partially compensate for the damage they cause to trees, tearing off their bark and causing them all sorts of other damage.

C. White reports that the seeds of the Australian quondong (Elaeocarpus grandis) germinate only after being in the stomach of emus, which love to feast on the fleshy, plum-like pericarp.

Aspen trees

One of the most obscure groups tropical trees- these are fig trees. Most of them come from Malaysia and Polynesia. Corner writes:

“All members of this family (Moraceae) have small flowers. Some - such as breadfruit trees, mulberries and fig trees - have flowers connected in dense inflorescences that develop into fleshy fruit. In breadfruit and mulberry trees the flowers are placed outside the fleshy stem that supports them; in fig trees they are inside it. The fig is formed as a result of the growth of the stem of the inflorescence, the edge of which then bends and contracts until a cup or pitcher with a narrow throat is formed - something like a hollow pear, and the flowers are inside... The throat of the fig is closed by many scales superimposed on each other...

The flowers of these fig trees come in three types: male flowers with stamens, female flowers that produce seeds, and gall flowers, so called because the larvae of small wasps that pollinate the fig tree develop in them. Gall flowers are sterile female flowers; breaking a ripe fig, it is not difficult to recognize them, since they look like tiny air balloons on the pedicels, and on the side you can see the hole through which the wasp got out. Female flowers recognized by the small, flat, hard, yellowish seed contained in each of them, and the male ones by their stamens...

Pollination of fig tree flowers is perhaps the most interesting form of relationship between plants and animals yet known. Only tiny insects called fig wasps (Blastophaga) are able to pollinate fig tree flowers, so the reproduction of fig trees depends entirely on them... If such a fig tree grows in a place where these wasps are not found, the tree will not be able to reproduce using seeds... ( Latest research It has been established that some fig trees, for example figs, are characterized by the phenomenon of apomixis (development of the fruit without fertilization). - Approx. ed.) But fig wasps, in turn, are completely dependent on the fig tree, since their larvae develop inside the flower-galls and the entire life of the adults passes inside the fruit - excluding the migration of females from a ripening fig on one plant to a young fig on another. Males, almost or completely blind and wingless, live only a few hours in the adult stage. If the female fails to find a suitable fig tree, she is unable to lay eggs and dies. There are many varieties of these wasps, each apparently serving one or more related species of fig tree. These insects are called wasps because they are distantly related to true wasps, but they do not sting and their tiny black bodies are no more than a millimeter long...

When figs on a gall plant ripen, adult wasps hatch from the ovaries of the gall flowers, gnawing through the wall of the ovary. The males impregnate the females inside the fetus and die soon after. The females climb out between the scales covering the throat of the fig tree. Male flowers are usually located near the throat and open by the time the fig is ripe, so that their pollen falls on the female wasps. The wasps, showered with pollen, fly to the same tree on which young figs are beginning to develop and which they probably find using their sense of smell. They penetrate young figs, squeezing between the scales covering the throat. This is a difficult process... If a wasp climbs into a fig gall, its ovipositor easily penetrates through a short style into the ovule, in which one egg is laid... The wasp moves from flower to flower until its supply of eggs runs out; then she dies from exhaustion, because, having hatched, she does not eat anything...”

Trees pollinated by bats

In temperate zones, most flower pollination is carried out by insects, and it is believed that the lion's share of this labor falls on the bee. However, in the tropics, pollination of many tree species, especially those that bloom at night, depends on bats. Scientists have shown that "bats that feed on flowers at night... appear to play the same ecological role as hummingbirds during the day."

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

1. The smell of most bat-pollinated flowers is very unpleasant to humans. This applies primarily to the flowers of Oroxylon indicum, baobab, as well as some species 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 their long red tongues into the nectar, either hover over the flower or wrap their wings around it. Large bats stick their snouts into the flower and quickly begin to lick the juice, but the branch falls under their weight and they fly into the air.

3. Flowers that attract bats belong almost exclusively to three families: bignonia (Bignoniacea), mulberry (Bombacaceae) and mimosa (Leguminoseae). The exception is Phagrea from the Loganiaceae family and the giant cereus.

Rat "tree"

The climbing pandanus (Freycinetia arborea), found in the Pacific Islands, is not a tree but a vine, although if its many trailing roots can find adequate support, it stands so erect that it resembles 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 over thirty related species have been found on the islands located to the southwest and east.

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

The woody yellow stems of yeye are 2-3 cm in diameter and are surrounded by scars left by fallen leaves. They produce many long adventitious aerial roots of almost equal thickness along the entire length, which not only supply the plant with nutrients, but also give it the opportunity to cling to 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 telling about it in more detail.

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

An 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 move from one flowering branch to another in search of food. By eating the fleshy bracts, rodents stain their whiskers and fur with pollen, which then ends up 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 bats that find these fleshy bracts quite tasty."

Ant trees

Some tropical trees are infested with ants. This phenomenon is completely unknown in temperate zone, where the ants are just harmless boogers that crawl into the sugar bowl.

IN tropical forests Everywhere there are countless ants of various sizes and with various habits - ferocious and voracious, ready to bite, sting or in some other way destroy their enemies. They prefer to settle in trees and for this purpose they 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 showed that their union is beneficial for both parties ( For lack of space, we will not here touch on the role played by ants in the pollination of some flowers or in the dispersal of seeds, or the ways in which some flowers protect their pollen from the ants.).

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

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

Regarding the latter, Darwin wrote:

“Protection of the foliage is ensured... 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 huge numbers, he several times noticed dark-colored Aphides. In his opinion, these small, painfully stinging ants bring great benefit 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-cutter ants, which, according to him, are very afraid of their small relatives.”

This union of trees and ants occurs in three ways:

1. Some ant trees have hollow branches or their core is so soft that the ants, when making a nest, easily remove it. Ants look for a hole or a soft spot at the base of such a twig; if necessary, they gnaw their way through and settle inside the twig, often expanding both the entrance hole and the twig 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 residents inside the leaves. This is done in two ways. Typically, ants find or gnaw an entrance at the base of the leaf blade, where it connects to the petiole; they climb inside, pushing apart the upper and lower covers of the leaf, like two pages stuck together - here you have a nest. Botanists say that the leaf “invaginates,” that is, it simply expands, like a paper bag, when you blow into it.

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

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

Ants in twigs

Spruce detailed his encounter with ant trees in the Amazon:

“Ant nests in the thickening of branches occur 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 at the tops of the shoots. These anthills are an expanded cavity inside the branch, and communication between them is sometimes carried out through passages laid inside the branch, but in the vast majority of cases - through covered passages built outside.

Cordia gerascantha almost always has bags at the branching site in which very angry ants live - the Brazilians call them “tachy”. C. nodosa is usually inhabited by small fire ants, but sometimes also by tachy. Perhaps fire ants were the original inhabitants in all cases, and the takhs are replacing them.”

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 the young stem of a tree or bush, and as it grows, sending out branch after branch, they make their passages 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 - "tangarana", and in both these countries the same name is usually used to designate both the ants and the tree in which they live.

In Triplaris surinamensis, a fast-growing tree distributed throughout the Amazon basin, and in T. schomburgkiana, a small tree in the upper Orinoco and Caciquiare, the thin, long, tube-shaped branches are almost always perforated with many tiny holes that can be found in the stipule of almost every leaf. This is a gate from which, at the signal of 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 retain the above-mentioned passages and bags as their permanent homes, and some species of ants generally all year round do not leave the trees. Perhaps the same applies to ants that build anthills on a branch from foreign materials. Apparently, some ants always live in their aerial habitats, 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. The most famous is the cecropia (Cecropia peltata) of tropical America, which is called the “pipe tree” because the Huaupa Indians make their blowpipes from its hollow stems. Ferocious Azteca ants often live inside its stems, which, as soon as you shake the tree, 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 tip of the internode the wall becomes thinner. The fertilized female gnaws through it and hatches her offspring inside the stem. The base of the petiole is swollen, on its inside Outgrowths are formed, which the ants feed on. As the growths are eaten, new ones appear. A similar phenomenon is observed in several other 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 shoots do not appear.

In some acacias, the stipules are replaced by large spines, swollen at the base. In Acacia sphaerocephala Central America ants penetrate these spines, clean 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 when any attempt is made to damage the tree in any way, the ants pour out in droves.

The old mystery of which came first, the chicken or the egg, is repeated in the case of the Kenyan black wattle (A. propanolobium), also called 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, but then they harden, turn black, and ants settle in them. Dale and Greenway report: “The galls at the base of the spines... are said to be caused by ants gnawing them out from the inside. When the wind gets into the openings of the galls, a whistle is heard, which is why the name “whistling thorn” arose. J. Salt, who examined galls on many acacias, found no evidence that their formation was stimulated by ants; the plant forms swollen bases, and the ants use them.”

The ant tree in Ceylon and southern India is Humboldtia laurifolia from the legume family. Its 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 Rubiaceae family, Willis notes that in two of them - D. petiolaris and D. hlrsuta - the stems directly under the inflorescence are swollen, and ants can enter the cavity through the resulting cracks. The third species, D. saccifera, has anthills on the leaves. The entrance, located on the upper side, is protected from rain by a small valve.

Corner describes the different types of macaranga ( local residents they call them "mahang") - the main ant tree of Malaya:

“Their leaves are hollow, and ants live inside. They gnaw their way out in the shoots between the leaves, and in their dark galleries they keep masses of aphids, like herds of blind cows. 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 shoots”, which are tiny white balls (1 mm in diameter), which consist of oily tissue - it also serves as food for ants... In any case, the ants are protected from the rain... If you cut shoot, they run out and bite... Ants penetrate young plants - winged females gnaw their way inside the shoot. They settle in plants that are not 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 out of the wide core between the nodes, like in bamboos, and the ants turn individual voids into galleries by gnawing through the partitions at the nodes.”

J. Baker, who studied ants on Macaranga trees, discovered that war could be caused 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 expanded tissues and integuments that form suitable sites for the emergence of ant colonies are found mainly in some South American melastomas. The most interesting of these is tococa, numerous species and varieties of which grow in abundance along the banks of the Amazon. They are found mainly in those parts of the forest that are subject to flooding when rivers and lakes flood or during rains. Describing the bags formed on the 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 extends from the main vein about 2.5 cm from the base of the leaf, and the bag occupies exactly this part of it - from the first pair of lateral veins downwards.”

This is where the ants settle. Spruce reported that he found only one species - Tososa planifolia - without such swellings on the leaves, and the trees of this species, as he noticed, 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 place of 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. 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 permanent habitation of ants, always have leaves with bags and are not free from them at any time of the year . I know this from bitter experience, since I have endured many fights with these warlike boogers, when I damaged their homes while collecting samples.

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

Ant nests on epiphytes and vines

The most notable of the epiphytes that shelter ants high among the branches of tropical trees are the eighteen species of Myrmecodia, which are found everywhere from New Guinea to Malaya and the far north of Australia. Another epiphyte often coexists with them - Hydnophytum, a genus that includes forty species. Both of these genera are members of the Rubiaceae family. Merrill reports that some are found in low-lying areas and even in mangroves, while others grow in primary forests at high altitudes. He continues:

“The bases of these trees, sometimes armed with short thorns, are very enlarged, and this enlarged part is pierced by wide tunnels into which small openings lead; Inside the heavily swollen bases of these plants, myriads of small black ants find shelter. From the top of a tuberous, tunnel-pierced base, stems rise, sometimes thick and unbranched, and sometimes thin and very branched; small white flowers and small fleshy fruits develop in the axils of the leaves.”

“Perhaps the most distinctive leaf adaptations are those observed in groups such as Hoya, Dlschidia and Conchophyllum. These are all vines with abundant milky sap belonging to the swallow family (Asclepmdaceae). Some of them hang on trees, like epiphytes or semi-epiphytes, but in Conchophyllum and some species of Noua, the thin stems fit tightly to the trunk or branches of the plant and the round leaves, located in two rows along the stem, are arched and their edges are closely pressed to the bark. Roots grow from their axils, often completely covering a piece of bark under the leaf - these roots hold the plant in place and, in addition, absorb the moisture and nutrients it needs; under each such leaf, colonies of small ants live in the finished dwelling.”

The distinctive pitcher plant of Southeast Asia, Dischidia rafflesiana, provides shelter for ants. Some of its leaves are sloughy, others are swollen and resemble pitchers. Willis describes them as follows:

“Each leaf is a pitcher with an edge turned inward, about 10 cm deep. An adventitious root grows into it, developing nearby on the stem or petiole. The pitcher... usually contains various debris caused by ants nesting there. Rainwater accumulates in most jugs... The inner surface is covered with a waxy coating, so the jug itself cannot absorb water and the roots absorb it.

A study of the development of the pitcher shows that it is a leaf, the lower part of which is invaginated.”

Nature's ingenuity knows no bounds! One proof of this is the history of nectar-eating bats and night-blooming plants, whose fates are closely intertwined in the forests of Central America. The size of ours thumb, the tiny bat of Commissaris ( Glossophaga commissarisi) most spends his life fluttering among tropical vines Mucuna and collecting nectar from their flowers. By generously sharing the “drink of the gods,” the plants receive an additional pollinator in return. Attracts animals during the day in bright light sunlight flowers flaunt multi-colored outfits, but at night, when even the most bright colors fade, nocturnal plants seem Mucuna To attract the attention of bats, they resort to sound.

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

At the biological station La Selva(Spanish for “forest”) in the north of Costa Rica, a tropical liana in a short time wove a green roof of leaves and flowers over a forest clearing. Reminiscent of chandeliers on the ceiling of a large, dark hall, palm-sized pale yellow inflorescences sway slowly. At sunset, the flowers begin to prepare to receive guests. The first to slowly move up is a light green sepal, covering the bud like a lid, and, rising, turns into a beacon. Just below, two small side petals spread out, revealing a gap at the base of the bud, from which a barely noticeable alluring garlic aroma spreads throughout the area. Mucuna use scent as a signal to attract nearby pollinators. But then, when the mice fly close enough, sound becomes the main attraction. Bats successfully use high-frequency sound to orient themselves in space. By emitting sound waves, animals use their very sensitive ears to detect the smallest changes in the signals reflected from objects. The incoming information is instantly processed by the brain, and the bat can instantly change its flight path, chasing a juicy mosquito, or deftly dart between flowering tropical trees. Most species of bats hunt insects, and with each flap of their wings they emit signals that travel long distances. Nectar-eating 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. The ability to better distinguish details comes at the cost of the range of such echolocation - it is only effective within a radius of 4 meters. In tropical thickets of Mucuna vines, beacon sepals serve as unique mirrors, reflecting signals from 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 the buds. They are definitely made for each other. A bat, climbing astride a flower, clings to the base of the petal with its paws, tucks its tail, pulls up its hind leg and sticks its head into the bud. The long tongue rushes inside, launching a “bomb” mechanism hidden in the flower: plunging deeper into the nectar, it causes chain explosions of the anther sacs, which abundantly cover the animal’s fur with a golden layer of fresh pollen. Bang! Bang! Bang! Ten buds exploded, nectar reserves were destroyed, and the bats went home. But the fast metabolism of chiropterans does not allow them to fly away for a long time. Each animal visits the flower a hundred times during the night. Type of vines Mucuna holtonii with their “bombs” and generous portions of nectar, they are one of the few species on which animals land and not just fly up. Other plants, not so rich in nectar, are not given such an honor: nectar-eating bats hover over them, emptying them in a fraction (1/5) of a second, without ever landing. About 40 species of the subfamily Glossophaginae constitute the elite " air force» nectarivorous bats. They belong to the family of leaf-nosed bats, which live in the tropics and subtropics of the Western Hemisphere. Their strangely shaped noses, which give the name to the whole family, allow them to masterfully emit complex echolocation signals. Pollination in exchange for nectar is a transaction between a plant and a bat, which biologists have dubbed the scientific term chiropterophilia (from the Latin name for bats - Chiroptera). For thousands of years, bat-pollinated plants have “figured out how to solve, quite elegantly, the difficult problem of attracting as many pollinators as possible with as little energy as possible. They didn't increase the quantity (or improve the quality) of nectar, but instead made it more efficient for their bat partners to collect. Plants display night flowers in spaces free for flight, so it is quite easy for bats to find them and collect nectar. (Besides, this is much safer - predators like snakes and possums simply have nowhere to hide.) In addition, the flowers mix sulfur compounds into their scents: such a bait works over long distances, and bats are unable to resist. However, the aroma is not for everyone, and on the contrary, it repels people, reminiscent of an imaginary mixture of the most unpleasant odors that exist in the world: it contains notes of the smell of sauerkraut, garlic, rotting leaves, sour milk and skunk. Mucuna and some other plants have gone even further - to attract the echolocators of bats, they have adapted the shape of their flowers. 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 sepals are beacons of buds Mucuna very similar to sound reflector beacons. They attract attention in the world of sounds, like the guiding light of a lighthouse in the dark. The hypothesis was confirmed after a series of experiments. The Gelversens continued their research on the acoustic characteristics of flowers in Erlangen, using a colony of laboratory bats. Under their guidance, student Ralph Simon taught the animals to drink nectar from randomly placed feeders. different shapes. The easiest and fastest way for the animals 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, round parts of the flower that contain nectar, the magazine editors mistakenly thought it was a fruit.) Intrigued, Ralph Simon traveled to Cuba, straight to where the flower was photographed. As a reward for his perseverance, he received confirmation of his hypothesis by seeing how bats drink nectar from a flower, and it generously covers them with its golden pollen.

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

Returning to the laboratory, Simon built similar beacons and attached them to the feeders. Ordinary flat beacons did not help much in detecting the feeder - the search time was almost the same as for feeders without identification marks. But saucer-shaped beacons cut this time in half! “The flat petal only makes a splash in the world of sound when the signal bounces off its surface,” explains Simon. “But the saucer beacon, when a bat approaches, sends back several strong signals, covering a wide 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. Inside, he installed a small ultrasound source and two receivers at the vertices of a triangle, exactly simulating the animal’s nose and ears. During the experiment, the source nose produced complex sequences of sounds at different frequencies, similar to the echolocation calls of bats, and Simon directed them at flowers mounted on a rotating stand and recorded the reflected sound waves registered by the receiver ears. So he managed to collect the acoustic characteristics of flowers of 65 species of plants pollinated by chiropterans. Each of the flowers Simon studied had a unique, distinct acoustic image, a kind of “fingerprint.” This study confirmed a fact long known to bats - flowers “speak” in their own languages. Back in the 1790s, Italian biologist Lazzaro Spallanzani was ridiculed for suggesting that bats “see” in the dark using their ears. A century and a half later, in the late 1930s, scientists confirmed this fact, establishing exactly how and by what mechanism bats “see” in the dark. And after 75 years, scientists found out that nocturnal plants help them “see”, adjusting the shape of their flowers in the process of evolution so that they are better heard by pollinators, and as a result, “sparkling” in the world of sounds as brightly as they sparkle in the rays of the sun the most colorful daytime brothers.

Bat-pollinated flowers are usually large, durable, produce a lot of nectar, are not brightly colored, or often open only after sunset, since bats feed only at night. Many of the flowers are tubular or have other structures to retain nectar. Many plants that attract bats for pollination or seed dispersal have flowers or fruits that either hang on long stalks below the foliage, where bats can more easily fly, or are produced on the trunks. Bats find flowers using their sense of smell, so the flowers have a very strong smell of fermentation or fruit. These animals, flying from tree to tree, lick nectar, eat parts of the flower and pollen, at the same time transferring it from one plant to another on their fur. They pollinate and disperse seeds of at least 130 genera of angiosperms. In North America, long-nosed bats pollinate more than 60 species of agave, including those used to make Mexican tequila. Flower bats pollinate mainly cacti (Pachycereen) and agaves. sausage tree, or Kigelia Ethiopian, growing in tropical Africa and in Madagascar, it is pollinated by bats. Bats pollinate plants such as:
Couroupita guianensis, Cephalocereus senilis, Adansonia digitata, Kigelia pinnata, Trianaea, Artocarpus altilis, Mucuna holtonii, Blue agave (Agave tequilana weber) azul), Cocoa (Theobroma cacao), Orchids from the genus Dracula, Chorisia speciosa, Durian civet (Durio zibethinus).

Pachycereus Pringle, pollinated by bats of the Sonoran Desert (Central America)

Selenicereus is another cactus pollinated by bats at night and bees during the day.

Bats that pollinate flowers feed on nectar. As an adaptation, they developed an elongated muzzle. In North America there is a genus of bats called long-nosed bats.

During cross-pollination, a recombination of hereditary characteristics of the paternal and maternal organisms occurs, and the resulting offspring can acquire new properties that the parents did not have. Such offspring are more viable. In nature, cross-pollination occurs much more often than self-pollination.

Cross-pollination is carried out with the help of various external factors:

·
Wind pollination. In wind-pollinated plants, the flowers are small, with a poorly developed perianth (does not interfere with pollen getting onto the pistil), often collected in inflorescences, a lot of pollen is produced, it is dry, small, and when the anther opens, it is thrown out with force. Light pollen from these plants can be carried by the wind over distances of up to several hundred kilometers. The anthers are located on long thin filaments. The stigmas of the pistil are wide or long, hairy and protrude from the flowers to better capture pollen. Wind pollination is characteristic of almost all grasses and sedges.

· Transfer of pollen by insects. The adaptation of plants to pollination by insects is the presence of sweet nectar, the smell, color and size of flowers (bright large single flowers or inflorescences), sticky delicate pollen with outgrowths. Most flowers are bisexual, but the maturation of pollen and pistils does not occur simultaneously, or the height of the stigmas is greater or less than the height of the anthers, which serves as protection against self-pollination. Insects, having flown up to a flower, are drawn to the nectaries and anthers and become dirty with pollen during their meal. When an insect moves to another flower, the pollen grains it carries stick to the stigmas.

· Pollination by birds. Flowers pollinated by birds secrete abundant liquid nectar (in some species it even flows out by the time the pollen ripens), but their smell is weak, which is developed with the poor development of the sense of smell in birds. But birds perceive colors well, so the color of most flowers they pollinate is striking, usually yellow or red, such as fuchsia, eucalyptus, many cacti and orchids. Often the flowers combine brightly contrasting colors: fiery red with pure green or lilac-black. Typically, such flowers are large or collected in powerful inflorescences, which is due to the need to attract birds with their appearance and contain large quantities of nectar.

· ABOUT dusting with water. Observed in aquatic plants. The pollen and stigma of these plants most often have a thread-like shape.

· ABOUT dusting with the help of animals. Bat-pollinated flowers are usually large, durable, produce a lot of nectar, are not brightly colored, or often open only after sunset, since bats feed only at night. Many of the flowers are tubular or have other structures to retain nectar. Many plants that attract bats for pollination or seed dispersal have flowers or fruits that either hang on long stalks below the foliage, where bats can more easily fly, or are produced on the trunks. Bats find flowers using their sense of smell, so the flowers have a very strong smell of fermentation or fruit. These animals, flying from tree to tree, lick nectar, eat parts of the flower and pollen, at the same time transferring it from one plant to another on their fur.

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