Early flowering herbaceous plants. Ecological groups of early spring flowering plants according to the method of pollination and the duration of the growing season Early flowering flowers pollinated by the wind

Introduction.

Spring, especially April and the first half of May, is a very suitable time for ecological studies of plants. During this period, transitional from winter to summer, you can see a wide variety of natural phenomena, moreover, in central Russia, where we live, all processes are so fast that many of them can be traced in development, and sometimes even from the beginning. to end.
In spring, the ecological diversity of communities is extremely fully revealed, and some groups of organisms can be observed only in spring, for example, ephemeroids. And the conditions for research are favorable - at this time, as a rule, the weather is dry and warm.
Scientists distinguish several groups of plants blooming in spring: (Biology at school No. 2, 1998 // Primroses: a research project for schoolchildren, p. 67)
1) Early spring plants that develop and bloom in early spring, shortly after the snow melts or even at the same time, long before the leaves bloom in tree and shrub species and most herbaceous plants, calendar - April and the first half of May (corydalis, goose onion, anemone, violets) .
2) Spring plants that give flowers after the first group or at the time of their flowering, calendar - in the second half of May (sour, crow's eye, Peter's cross).
3) Late-spring plants blooming already in the beginning and second decade of June (fragrant woodruff, two-leaved wild rose, wild rose, honeysuckle, etc.) This paper presents the results of studying the first group of plants, i.e. early spring plants.

Objective: study of early spring flowering plants and their ecological groups.

Tasks:

• identify species of early spring plants;
• determine the frequency of their occurrence;
• make a herbarium;
• give a biological description of the species;
• establish ecological groups of early spring flowering plants;
• identify plant species in need of protection;
• formulate recommendations for the rational use and protection of early spring plants.

The study was conducted 2 kilometers east of the village of Kazachy, Prokhorovsky district, from April 1 to May 10.

Research methodology

The study of the territory for the detection of early spring flowering plants was carried out by the route method. The routes covered the eastern territory of the vicinity of the village and all the main habitats: forest edges, glades, meadows, ditches along the roads, wastelands. The research was carried out in the period from April 1 to May 10, access to the route was carried out twice a week.
In the process of work on the route, the frequency of occurrence of these plants was recorded, the records were kept by eye, all plant species were divided into three groups: they are common and abundant, they are moderately frequent and rare.
Also, along the route, the habitats of plants and their need for certain environmental factors were noted, for the subsequent determination of ecological groups.
Herbarium materials were collected. Herbaceous plants were collected without underground organs (except for those where it was necessary to identify the species, such as Corydalis).
A plan of the surveyed area was drawn up, it shows the habitats of the species. Each species is given a brief description, photographs are taken. The results are presented in the form of herbariums and tables.

General characteristics of early spring plants.

Plants need sunlight to function properly. It is in the light that photosynthesis processes take place, when organic substances are formed from inorganic substances, which are then used by plants for their development.
In the April forest, the trees and shrubs are not yet covered with foliage, nothing prevents the sunlight from penetrating to the very ground. This is the main reason that many plant species in the process of evolution “choose” early spring for their development.
In addition, the earth after the snow melts is saturated with moisture, which is also a necessary condition for the normal development of the plant organism.
Already from the moment of snow melting in the forest community, in many plants one can observe already developed stems with young, slightly green leaves, as well as formed buds. This group of plants has another feature of development. In the second half of summer and autumn, early spring flowering plants experience a significant increase in renewal buds with the isolation of inflorescences laid in them. The growth rate of points increases as autumn approaches. During the winter months, both pollen grains and embryo sacs are formed in the flowers of early spring plants. Without exposure to low temperatures for a certain period, early spring plants do not develop. Even in those cases when the soil in the forest really freezes, the young parts of the plants do not freeze. This phenomenon is explained by the fact that the freezing temperature of cell sap in overwintering plants is much lower than 0C. In hibernating organs, starch is replaced by sugar. The sugar concentration is high, the freezing point is lower.
All early spring flowering plants are perennials, many store spare nutrients in tubers, bulbs, rhizomes, stem core for quick and early flowering.
The “transparency” of a leaf-free forest plant is also used for pollination. In a bare spring forest, nothing prevents the wind from transferring pollen from male flowers (collected in “dusty” catkins) to female flowers, consisting of only small sticky pistils. This is very typical for trees and shrubs that bloom in spring. Another interesting phenomenon for the spring forest is wind-pollinated grasses, for example, hairy sorrel. Her flowers are small, inconspicuous, but the absence of other herbs and the mass accumulation of these plants allows her to pollinate. The pollen is light and very dry.
Low-growing insect-pollinated plants attract the first insects with bright flowers. Who will notice their flowers in the dusk of a summer forest? And in the spring, when the lower tiers of the forest are well lit, yellow (anemone), blue (violets), purple (tenacious, Corydalis) and pink flowers are best seen here.
But the small plants allocated to the group of "ephemeroids" use all the favorable spring factors most fully.
Ephemeroids- This is a very special group of plants with peculiar habitats. In short, these are those plants which, having subterranean organs, go through their annual growing season as quickly as the ephemera. The word "ephemeral" is associated with something beautiful, but fleeting, short-lived. In our forests, their "hurried" life is associated with a sharp change in the light flux. If at the beginning of May the illumination and temperature in the forest is comparable to the illumination and temperature in open areas, then at the height of summer in the forest it is both darker and colder. This prevents not only the normal development of plants, but also the normal life of pollinators. (Biology at school. No. 1 1994 // Spring phenomena in plant life, p. 63)
An example of them can be various types of corydalis, goose onions, anemones. They are born immediately after the snow melts. It is quite cool at this time of the year, but the ephemeroids develop very quickly nonetheless. After a week or two, they already bloom, and after another two or three weeks, their fruits with seeds already ripen. At the same time, the plants themselves turn yellow, lie down on the ground, and then their aerial part dries up.
All ephemeroids are perennial plants. After the aerial part dries up, they do not die. Their living underground organs are preserved in the soil: tubers, bulbs, rhizomes. These organs are repositories of reserve nutrients. It is due to this building material that ephemeroids develop so quickly in the spring. With such a short growing season, and even with an unfavorable spring temperature regime, it is impossible to accumulate a lot of nutrients necessary for the development of tall and powerful stems and large leaves. Therefore, all our ephemeroids are small in size. (Petrov V.V. The flora of our Motherland. M: Enlightenment, 1991, p.63).
There is another problem with perennial early spring flowering plants - seed dispersal. By the time their seeds ripened, trees and shrubs were already covered with leaves, summer grasses had risen. There is practically no wind in the forest, so the distribution of seeds with its help is not effective, and even animal hair cannot be reached. They also do not have time for the ripening of juicy berries that forest animals would eat. But who is always in abundance in the forest is ants. On the fruits or seeds of these plants, special fleshy appendages are formed, rich in oil - elaiosomes ( from the Greek elaion - oil, soma - body), which attract ants. Plants that spread their seeds with the help of ants are called myrmecochores. Myrmecochores include all our ephemeroids, as well as approximately 46% of all forest herbaceous plants. (Biology at school. No. 2, 1998, p. 70).

Research results

In the course of the research work, 17 species of early spring flowering plants were identified:
1. Warty birch.
2. Veronica oak.
3. Anemone is rancid.
4. Goose bow.
5. Pedunculate oak.
6. Tenacious creeping.
7. Starry oak.
8. Ash-leaved maple.
9. May lily of the valley.
10. Common hazel.
11. Mother and stepmother.
12. Hairy hairy.
13 Spring Companion.
14. Trembling poplar (aspen).
15. Dog violet.
16. Corydalis dense.
17. Common bird cherry.

Having studied the characteristics of these plants, I divided them into ecological groups 1) in relation to light; 2) in relation to moisture;
3) according to the method of pollination; 4) ephemeroids; 5) according to life forms.

By in relation to light It is customary to distinguish three main groups of plants: 1. heliophytes- (from the Greek "helios" - the sun, "phyton" - a plant) plants of open spaces, well-lit habitats; 2. facultative heliophytes- species that can live in full sunlight, but tolerate some dimming;

3. sciophytes- (from the Greek "skia" - shadow) species that do not grow in open spaces. (Life of plants, vol. 1 M: Enlightenment 1997, p. 65). These three categories of plants are, of course, not sharply demarcated. Not always the growth of plants in illuminated places (or shaded) indicates their actual need for light.

By in relation to moisture.
Plants are classified according to their ability to retain moisture.

1. Poikilohydride these plants easily absorb and easily lose water, tolerate prolonged dehydration. As a rule, these are plants with poorly developed tissues (bryophytes, ferns, algae). 2. Homoyohydrides- plants capable of maintaining a constant water content in tissues themselves, among them there are different ecological groups (Plant Life, vol. 1, p. 76):
- hydatophytes– aquatic plants wholly or almost wholly submerged in water;
- hydrophytes- water-terrestrial, attached to the soil near water bodies and on abundantly moistened soil far from water bodies;
- hygrophytes- plants living on abundantly moist soils and at high humidity;
-mesophytes- plants that live with sufficient moisture;
- xerophytes- plants that can extract moisture when it is lacking, limit the evaporation of water or store water.
Ecological groups of early spring flowering plants in relation to light and moisture.

The name of the species.	In relation to the world.	In relation to hydration.
Warty birch	heliophyte	mesophyte
Veronica oak	heliophyte	mesophyte
Anemone buttercup	sciophyte	mesophyte
goose bow	heliophyte	mesophyte
Pedunculate oak	heliophyte	mesophyte
tenacious creeping	heliophyte	mesophyte
chickweed oakwood	heliophyte	mesophyte
Ash maple	heliophyte	mesophyte
May lily of the valley	Facultative heliophyte	mesophyte
common hazel	Facultative heliophyte	mesophyte
Coltsfoot	heliophyte	mesophyte
Ojika hairy	Facultative heliophyte	mesophyte
Sochevichnik spring	sciophyte	mesophyte
Poplar trembling	heliophyte	mesophyte
dog violet	Facultative heliophyte	mesophyte
corydalis dense	heliophyte	mesophyte
Common bird cherry	heliophyte	mesophyte

Analyzing the collected data presented in the table, all the early spring flowering plants that I found - mesophytes, and all these plants are heliophytes, with the exception of spring sochechnik, buttercup anemone - they sciophytes.

By pollination method
All early flowering plants are cross-pollinated by wind and insects. It is necessary to bloom early for successful pollination, especially for wind-pollinated ones, when there is still no foliage on trees and shrubs. Male inflorescences can be many times larger than female single or clustered flowers in order to produce as much fine, dry and very light pollen as possible. They say about such flowering - the plant "dusts".
Ephemeroids

Plants that quickly go through their annual growing season.

Ecological groups of early spring flowering plants according to the method of pollination and the duration of the growing season.

The name of the species.	Pollination method.	By the length of the growing season.
Warty birch	Wind pollinated.
Veronica oak	Insect pollinated.
Anemone buttercup	Insect pollinated.	Ephemeroid
goose bow	Insect pollinated.	Ephemeroid
Pedunculate oak	Wind pollinated.
tenacious creeping	Insect pollinated.
chickweed oakwood	Insect pollinated.
Ash maple	Wind pollinated.
May lily of the valley	Insect pollinated.
common hazel	Wind pollinated.
Coltsfoot	Insect pollinated.
Ojika hairy	Wind pollinated.
Sochevichnik spring	Insect pollinated.
Poplar trembling	Wind pollinated.
dog violet	Insect pollinated.
corydalis dense	Insect pollinated.	Ephemeroid
Common bird cherry	Insect pollinated.

By life forms.
The term "life forms" was introduced in the 80s of the 19th century by the famous Danish botanist E. Warming, one of the founders of plant ecology. Warming understood the life form as “a form in which the vegetative body of a plant (individual) is in harmony with the external environment throughout its entire life, from the cradle to the coffin, from seed to death” (Life of plants, vol. 1 p. 88) . Speaking about the harmony of a plant with the environment, we mean the adaptability of plants to the complex of external factors that have been historically developed in the course of evolution, which dominate in the area of ​​its distribution.
The most popular among botanists is the classification of life forms proposed by the Danish botanist K. Rawinker (Life of Plants, vol. 1 p. 91). He singled out one sign - the location of renewal points from the surface of the earth, from which new shoots will develop:
1.Fanerophytes(Greek "Phaneros" - open, obvious) - in this type of plants, the points of renewal overwinter openly, quite high. They are protected by special bud scales. These are all trees and shrubs.
2. geophytes(Greek "geos" - earth) - renewal buds are stored in the earth. The above-ground part dies off for the winter. New shoots develop from buds located on bulbs, tubers or rhizomes wintering in the soil.
3. Hemicryptophytes(Greek "hemi" - semi-, and "crypto" - hidden) are herbaceous plants whose renewal buds are above the soil level, often under the protection of fallen leaves and other plant debris.

4. X amephites(renewal points at a height of 20-30 cm above the ground)

5. T erophytes(renewal buds in seeds). But I did not find such early spring flowering plants.

During the work, I carried out an eye count of the frequency of occurrence of species, which I displayed in the table.

plant species	life form	Frequency of occurrence	Habitat
Warty birch	Fanerofit	Often	surrounding forests
Veronica oak	geophyte	Often	Wastelands, forest edges.
Anemone buttercup	geophyte	Rarely	Thickets of shrubs.
goose bow	geophyte	Often	Arable lands, forest edges, slopes, ditches.
Pedunculate oak	Fanerofit	Moderately often	surrounding forests.
tenacious creeping	Hemicryptophyte	moderately often	surrounding forests.
chickweed oakwood	geophyte	Often	Surrounding forests, edges.
Ash maple	Fanerofit	Rarely	Edges of the forest, settlement.
May lily of the valley	geophyte	Often	Surrounding forests, edges.
common hazel	Fanerofit	Often	Edges of the forest.
Coltsfoot	geophyte	Often	Ditches along roads, fields.
Ojika hairy	geophyte	Often	surrounding forests.
Sochevichnik spring	geophyte	Often	surrounding forests.
Poplar trembling	Fanerofit	Often	Edges of the forest.
dog violet	geophyte	moderately often	Surrounding forests, edges.
corydalis dense	geophyte	Rarely	Edges of the forest.
Common bird cherry	Fanerofit	moderately often	Edges of the forest.

Findings.

Based on the study:

1. 17 species of early spring flowering plants were found.
2. Most of these plants are found moderately often and often in the vicinity of the village.
3. The main ecological groups of these plants are:
- in relation to the light - heliophytes;
- in relation to moisture - mesophytes;
- according to the method of pollination - wind-pollinated and insect-pollinated,
- according to life forms - phanerophytes, geophytes, hemicryptophytes.
4. The presence of ephemeroids was revealed.
5. Among the early spring plants, no protected ones have been identified.

Conclusion.

In the course of my research work, I did not identify rare and protected species among early spring flowering plants. But, nevertheless, they need protection. Appearing first after a long winter, they attract increased attention, which leads to a massive collection, especially those species that have beautiful flowers (corydalis, anemone, commensals). Explanatory work can save them from thoughtless collection, and not only among children, but also among adults. Many of the species presented in this work are medicinal. It is very important that these plants do not fall into the lists of endangered ones.
I intend to continue my work, because it seems to me that I have not met all the plants of this group yet.
The results of my work can be used by students of the 6th grade when studying the vegetation of our region in biology lessons.

List of used literature.
1. Plant life. Edited by Fedorov A.A. M: Enlightenment, 1974.
2. Petrov V.V. The flora of our Motherland. M: Enlightenment, 1991.
3. Tikhomirov V.N. Key to higher plants of the Yaroslavl region. Yaroslavl, Upper - Volga book publishing house, 1986.
4. Biology at school No. 1. 1994 // Shipunov A.B. Spring phenomena in plant life.
5. Biology at school number 2. 1998 //Klepikov M.A. Primroses.
6. Biology at school number 2. 2002 //Antsiferov A.V. Early spring field trip with sixth graders.

wind pollinated early flowering plants

1. Early-flowering plants: buttercup anemone, oak anemone, spring nettle, dense corydalis, European hoof, coltsfoot, yellow goose onion, Siberian blueberry, drooping birch, gray obkha, aspen.
   Pollinated by the wind: drooping birch, gray obkha, aspen.

   The significance of early flowering lies in the fact that a lot of light is required for the formation of seeds,
   so they bloom before the leaves on the trees.
   In addition, the absence of leaves facilitates pollination, especially with the help of wind.

   In plants pollinated by the wind, flowers are diametrically opposed to flowers that are pollinated by insects.
   Wind is an elemental factor and can carry pollen in different directions.
   To use it, plants need completely different flowers, as in insect pollination.
   When pollinated by the wind, there is no need to spend valuable materials on the bright color of flower covers, on the formation of sweet nectar, fragrant aroma.
   Other devices were developed here, aimed at simplifying the structure of the flower.

   Therefore, the flowers of wind-pollinated (anemophilic) plants are inconspicuous, do not emit any odor, do not emit nectar. Their perianth is very poorly developed or completely absent. He is not needed here. On the contrary, the anthers extended far outward are freely fanned by the wind (cereals, sedges), which blows pollen out of them and disperses it through the air. Even a light breeze shakes catkins, panicles, stamens.

   Our trees and shrubs (poplar, hazel, etc.) usually bloom in spring, when strong winds blow and the foliage has not yet blossomed, so that the wind blows pollen onto the flowers without hindrance. Wind-pollinated plants do not grow alone, but form large thickets, which also increases the chances of their flowers being pollinated. The wind scatters uselessly a lot of pollen, so plants produce it in huge quantities. For example, in an earring of an ordinary hazel, there are up to a million pollen cells. And when the pine blossoms, whole clouds of yellow pollen rise in the air, which settles on the ground in the form of the so-called sulfur rain. Pine dust particles also have special devices for flying in the form of two balloons. In general, all wind-pollinated plants have fine, light, dry pollen. Thanks to this, the wind easily blows it out of the anthers.

   And the stigmas, in turn, are well adapted to trapping pollen. Like the anthers, during the flowering period they are exposed far outside and look like thick feathers (cereals), long filaments (corn, sedge) or tassels (hazel).

   With the help of wind in Central Europe, about 19% of plants are pollinated. Among them are such common trees and shrubs as spruce, pine, oak, alder, birch, aspen, elm, ash, hornbeam, and herbaceous plants, grasses, sedges and pondweeds growing in water. Wind pollination occurs in dry weather, while pollen does not spill out during rain.

   en.wikipedia.org/wiki/Wind pollinated_flowers

   http://atloka.narod.ru/Opulenie/opulenie.htm

There are many classifications of plants, but one of the main ones is the one based on the nature of pollination. From this point of view, crops are divided into several large groups: wind-pollinated, pollinated by animals (mainly insects, so we will call such plants insect-pollinated) and water (hydrophilia, is observed infrequently, therefore it will not be considered). Representatives of all these groups have cross-pollination, that is, the transfer of pollen with outside help (the opposite of self-pollination).

To find out what wind-pollinated plants are, you must first understand the features and differences of each group.

Plants, as we have just found out, can be pollinated both from the wind and with the help of insects.

Wind pollinated crops, their signs

To begin with, plants that are part of this group (they are also called anemophilous) under certain circumstances can be pollinated by insects, although this does not happen often. Such plants are distinguished by numerous small branches, as well as by the fact that they are able to produce a large amount of pollen (each specimen produces several million pollen grains). In many crops (such as, for example, mulberry or hazel), the formation of flowers begins even before the leaves bloom.

The flowers themselves are often inconspicuous and collected in small inflorescences. In a panicle, for example, this is a complex spikelet. The inflorescence produces many light and small pollen grains.

Note! As a rule, crops pollinated by the wind grow in groups. Moreover, wind-pollinated plants include not only trees (birch, alder, etc.), but also grasses (sedge, timothy) and bushes.

Insect pollinated crops

A distinctive feature of these plants (by the way, they are also called entomophilous) is that they bloom after the leaves appear. Temperature conditions play an important role here: when the temperature rises, insects appear that carry pollen. In addition, all insect-pollinated crops have nectaries.

The most common representatives of the group include willow. Willow flowering can be observed both before and after foliage formation. But early flowering has nothing to do with wind pollination - plants resort to such a “reception” solely to fight competitors for pollinating insects.

Table. Comparative characteristics of wind- and insect-pollinated crops

Flower Features	anemophilous plants	entomophilous plants
Nectar	Is absent
Corolla	Missing (or, alternatively, looks nondescript)	Bright
Smell	Is absent	Available to most of the representatives
The location of the stamens	Open (anthers are located on large threads)	Inside the flowers
Pollen	Small, dry, large	Sticky and large, in small quantities
Stigmas of pistils	Large	small

Anthers of anemophilous cultures are carried outside the flowers. The stigmas of the pistils are large and “shaggy”, which allows them to catch dust particles that fly in the air. Also, such plants have special adaptations, so to speak, due to which pollen is not wasted in vain, but falls mainly on the stigmas of other representatives of its species.

And now let's get acquainted in more detail with the features of crops pollinated by the wind.

Features of anemophilous plants

All representatives of this group are characterized by the following features:

• inconspicuous or inconspicuous flowers (explained by the fact that they should not attract insects);
• small and dry pollen grains;
• long threads on which anthers hang.

Now more. The main feature of all wind-pollinated crops is the unattractiveness of flowers, manifested in the absence of nectar, smell and bright colors. At the same time, pollen grains that develop in large quantities are extremely small: the average weight of one dust grain is 0.000001 mg. Let's give a small comparison: a speck of pumpkin dust - a plant pollinated by bees - weighs a thousand times more, i.e., about 0.001 mg. The horse chestnut inflorescence alone is capable of forming 42 million grains, while the rye inflorescence is ten times smaller (4 million 200 thousand). The peculiarities of the pollen of anemophilous plants include the fact that it, being completely devoid of adhesive substances, often also has a smooth surface.

Note! Wind pollinated crops do not have nectar, but they are often visited by insects that feed on pollen. However, these insects play only a minor role as vectors.

What plants can be wind pollinated?

Below are representatives of wind-pollinated crops.

1. Birch family. The most common member of the family in Europe and Asia is the warty birch, which blooms in early spring and is distinguished by complex inflorescences-earrings (the latter are used in medicine).

   

2. Aspen and poplar. These are the only representatives of the willow family that do not have nectaries. All others are pollinated by insects.

   

3. Monoecious plant with same-sex flowers. Flowering of catkins is observed even before the foliage appears.

   

4. All members of the family are pollinated by wind. The most common of them include walnut, gray and black walnut, as well as hazel.

   

5. Alder. This tree also blooms before the leaves appear. But, characteristically, some types of alder bloom in autumn, when the leaves fall. Earrings in this case are single-sex.

   

6. Beech family. Monoecious wind-pollinated crops, the most famous of which is oak. By the way, in nature there are over 500 varieties of oak, and all of them begin to bloom simultaneously with the appearance of leaves. The family also includes edible chestnut (not to be confused with horse chestnut) and, in fact, the beech itself.

   

7. In this monoecious culture, the catkins also begin to bloom at the same time as the foliage appears.

   

8. Representative of the cereal family, which includes six species, of which only one is cultivated.

   

   

9. Herbs. Wind-pollinated grasses primarily include cereals, plantain, sedge, nettle, hops and hemp.

   

Note! The list contains only the most common representatives of anemophilous plants, so it cannot be considered complete.

wind pollination process

Pollen dispersal by wind can hardly be considered a controlled process. Therefore, the probability that the grains will fall on the stigmas of their own flowers is quite high. Self-pollination, as is known, is undesirable for such plants, and therefore flowers have widely developed various adaptations that prevent this. So, most often the stigmas and anthers do not ripen at the same time. For the same reason, some wind-pollinated crops have dioecious flowers.

Most of the trees pollinated in this way bloom in early spring, that is, before the foliage blooms - this is also a device that prevents self-pollination.

This is especially pronounced in hazel and birch. And no wonder, because thick leaves would be a serious obstacle to moving pollen grains.

It is worth mentioning other devices. The stamens of most cereal plants begin to grow very quickly when the flowers open, and the growth rate can reach 1-1.5 mm / min. After a while, the length of the stamens is three to four times greater than the original, they go beyond the flower and hang down. And only after the dust particles are below, they crack. At the same time, the anther itself is slightly bent, forming a kind of bowl where the pollen is poured. As a result, the grains do not fall to the ground, but calmly wait for a gust of wind to leave the anther.

Note! In some grasses, the pedicels open up before flowering, forming an angle of up to 80° between them. As a result, the pollen is blown away by the wind. At the end of the flowering period, the flowers return to their original position.

Also, the position of the inflorescence can change in hornbeam, poplar and birch. At first, the inflorescences “look” up, but before opening the anthers, the earring stem extends, and they (the inflorescences) hang down. Flowers move away from each other and at the same time become accessible to the wind. Pollen grains fall on the scales of the lower flowers, from where they are blown away.

Some anemophilous plants (by analogy with entomophilous ones) have "explosive" flowers. So, in one of the varieties of nettle, the stamens during the ripening period are so tense that, after opening, they sharply straighten and get rid of the grains of bursting anthers. At such moments, dense clouds of pollen are observed above the flowers.

We also note that the pollen of wind-pollinated crops may not always crumble, but only if the weather is favorable. The street should be relatively dry, the wind should be weak or medium. Often, morning hours are most suitable for pollination.

Conclusion

As a result, I would like to give a few words to the planting of wind-pollinated crops. We will immediately make a reservation that it is not necessary to mix such plants, since each species has its own adaptations and principles. All grasses, as noted above, are anepophilic and all of them bloom only after foliage appears on the trees. But cereals are not "loners", they grow in groups - and large ones - in steppes, meadows, etc. (in other words, in open space).

But with bushes and trees, things are different: these crops, growing in forests, are located at a certain distance from each other.

Video - Wind Cross Pollination

In early spring, in a broad-leaved forest, from afar, the medicinal lungwort (vague lungwort) is striking with lilac flowers ( Pulmonaria officinalis or P. obscura) (Fig. 136), the borage family (Boraginaceae). Lungwort is a plant with a pronounced snowy development. Flower buds die after fruit ripening. Vegetative shoots do not develop under snow; they assimilate in summer with full shading, remaining green until late autumn.

Freshly opened flowers have a bright pink color, later it turns purple, and finally blue. Here there is a change in the reaction of cell sap from acidic (pink color) to alkaline (blue color). For this property of flowers to change their color, the people call the lungwort "Ivan da Marya". This name is given to plants with a double color of the corolla. Lungwort flowers have another interesting feature. They have the so-called heterostyly, or multi-columnity, a kind of adaptation that provides plants with cross-pollination. If we compare the flowers of the lungwort, then the larger ones have a long column and short

chinks reaching only to the middle of the corolla tube, while other, smaller flowers are equipped with long stamens, reaching almost the teeth of the corolla and a short pistil. On one stem of lungwort, flowers of only one type are located. Lungwort flowers with nectar secreted by a four-lobed gland under the ovary. During self-pollination, as well as during pollination by pollen of other specimens of the same form, the fruits do not develop. If you artificially delay the visiting of flowers by insects, then the fruits also do not form. The selection of pollinating insects is carried out by placing the nectar at the very base of the corolla tube, as a result of which only those insects whose proboscis is not shorter than 8 mm can get it. Cross-pollination is done by bumblebees and butterflies.

Against the background of bright flowers of early spring plants, European hoof stands out with its overwintered dark green leaves in early spring ( Asarum europaeum) (Fig. 18) . Flowering at the hoof begins very early, as soon as its dark red flowers appear from the buds located directly on the rhizomes lying on the ground. The flowers are inconspicuous and barely noticeable under the leaves. They have a three-membered perianth, an inferior ovary and 12 stamens, which are initially bent down; in the center is placed a column with a wide 6-lobed stigma. In the flower, simultaneous maturation of the genital organs is observed. The stigma of the ungulate is ready to receive pollen much earlier than the anthers open, even before the flower itself opens. Before the flower opens, when the tepals are still connected, various small flies penetrate into the gaps between them and, if they have been on another flower before and got dirty in its pollen, they pollinate the flower. Insects, apparently, are attracted to the hoof flower by a peculiar peppery smell inherent in all parts of the plant. Later, when the anthers ripen, the tepals diverge, the insects get dirty in the pollen and, sprinkled with it, get out and fly to the neighboring flower.

At the beginning of flowering, the hoofs are bent down, later, as they fade, they change their position and, straightening up, come into contact with their anthers with the stigma lobes. As a result, self-pollination occurs, which is a reserve here. Wild hoof flowers are highly prolific.

The seeds are dispersed by ants, which eat the fleshy appendage without touching the seed itself, and take them all over the forest. The people call wild ginger wild pepper, for the light pleasant aroma of freshly ground leaves, and the British call it wild ginger.

In broad-leaved forests, perennial hawk is also often found ( Mercurialis perrenis) (Fig. 25) from the Euphorbia family, but without milky juice. Despite its early development, which begins in autumn and continues under snow in winter, hawthorn retains green leaves until late autumn and dominates the grass cover of the forest in summer. In early spring, on its still low stems in the axils of the leaves, long, somewhat bent earrings, consisting of small, nondescript flowers, are noticeable. They are unisexual. Male flowers consist of tripartite perianths and 9-12 stamens, while female flowers have a two-celled ovary with two filiform columns and sticky stigmas. Blueberry is a dioecious plant, male and female flowers are on different specimens, since blueberry reproduces beautifully with the help of underground rhizomes, it always grows in large thickets-clones; some of them are male and others are female. The blueberry is pollinated by the wind, so its flowers are devoid of nectar and aroma, they are inconspicuous.

In the history of botany, the prolesnik is known for being one of the first objects of experiments by R. Camerarius in 1691 to prove the existence of sex in plants. Almost all parts of the woodweed are poisonous.

The most widespread early-flowering plants of the broad-leaved forest are strings, corydalis, chistyak, goose onions.

Anemone buttercup ( Anemone ranunculoides) (Fig. 139) is a rhizomatous plant with a low thin stem, bearing a whorl of three tripartite leaves, which differ from the leaves extending from the rhizome only in short petioles. Blooms in late April - early May; by the end of May, the above-ground parts of the plant die off and only rhizomes remain underground, consisting of thickened short segments.

Flowers solitary or in number of two (rarely more), on long stalks, regular. Perianth simple, corolla of 5 bright yellow, pubescent petals on the outside. Stamens and pistils numerous.

When, after snowfall, the cranked stem breaks through the soil and forest floor, the leaves protect the flower bud with a simple perianth, acting as a calyx. Anemones, like all early flowering plants, have a snowy development. In autumn, at the top of the rhizome in the soil, you can see all the parts of the plant that will develop in the spring, but for the normal development of the plant, prolonged exposure to low temperatures is required. Bud growth begins in January, in February, formed buds can be seen on the shoots, in March the plant leaves the soil and develops under the snow. In mid-April, stems with folded leaves and developed buds are 3 cm long.

Buttercup anemone blooms in the suburbs of Cheboksary in the third decade of April - the first decade of May, in June the aerial parts of the plant die off, and the laid buds fall into a dormant state. During this short period, nutrients are deposited in the rhizome, due to which early flowering becomes possible. In the flower of the anemone luteus, a large amount of pollen is formed, for which bees, bumblebees and other insects fly. At night and in bad weather, the flowers close and droop, this protects the pollen from moisture.

Similar biological features are characterized by oak anemone, the flowers of which are white in color and larger in size (bigger). Oak anemone in Chuvashia is a protected plant, as its numbers are declining annually in the forests around large settlements.

Yellow goose onions are widespread in our forests ( Gagea lutea) (Fig. 140) and small goose onion ( G. minima) lily family ( Liliaceae), the wintering organ of which is the bulb. Yellow goose onions have small shoots on the bulbs in autumn. Spring development begins in January; at the end of February, the leaves pierce the fallen leaves and come into contact with the snow; by the time of snowfall, the leaves are green in color and reach up to 10 cm in length. Chlorophyll is formed under the snow at the end of winter. Before blooming, the inflorescence is protected by two stem leaves; the basal leaf has an awl-shaped apex that pierces the forest litter. Goose onion flowers are odorless, close at night and in cloudy weather. At the base of the tepals there are nectaries. Cross-pollination with the help of bees and bugs is possible only at the beginning of flowering, due to weak proterogony. By the time the fruits ripen - trihedral boxes, the stem droops to the ground. This facilitates access to the seeds of ants, which take away seeds that have oily appendages.

The small goose onion is distinguished by its smaller size, two bulbs and other conditions of existence, i.e., in low places of relief.

Rice. 139. Butterfly anemone Fig. 140. Goose onion yellow

(Anemone ranunculoides) (Gagea lutea)

A companion of goose onions in deciduous forests is

sya corydalis( Corydalis). In the forests of Chuvashia, 3 species are common: Corydalis Gallera ( C. Halleri) (Fig. 141) , corydalis medium ( C. intermedia)them. Marshall( C. Marschalliana) fume family ( Fumariaceae). They are widely found wherever oaks grow and, like other early-flowering plants, are characterized by under-snow development. The corms germinate in autumn, during the first half of winter they are dormant, and in February they begin to grow. The first leaf of Corydalis Haller and the middle one differ from the rest, strongly indented leaves. It has a light and pointed top. Initially, the entire inflorescence is protected by a leaf that breaks through the soil. Zygomorphic flowers are collected in an inflorescence - a brush and emits a fragrance. The nectary is hidden in the depths of the long spur of the upper petal, and pollination is done by long-proboscis bees; bumblebees and ants often gnaw through the spur, collecting nectar. The seeds are dispersed by ants that eat the fleshy appendages.

Above-ground shoots die off completely at the end of May, the corm remains in the soil, which is renewed annually. In Corydalis, the change of corms begins even before the flowering of the plant. If in early spring, when the corydalis is just beginning to develop,

cut through the tuber, then in the middle of the old tuber you can see a white ring of a growing new young tuber. This ring will gradually thicken and by the height of the flowering of the Corydalis will turn into a new tuber. In last year's tuber, nutrients are consumed for the development of the plant, and later they are completely replaced by a new tuber growing from the inside. The new corm is covered by the dead last year.

Rice. 141. Corydalis Gallera.

1 - peduncle and leaf blade, 2 - corm in section, 3 - flower,

4 - flower (enlarged)

The process of changing the Corydalis corm, as well as the Chistyak, can be traced on one excursion, only for this it is necessary to find both flowering and individuals just beginning to develop and, having caught on them certain moments of the observed phenomenon.

Corydalis corms are of stem origin.

Chistyak tubers ( Ficaria verna) (Fig. 142) are thickened adventitious roots. During flowering, there are few insects, so the plant reproduces mainly vegetatively. Vegetative reproduction occurs with the help of root tubers and brood buds formed in the axils of the leaves. Shortly after flowering, single fruits are formed, and the whole plant turns yellow and dies off in the first half of June. During the summer, the chistyak is at rest. Its development begins in September-October, when stem bulbs and root tubers germinate. However, even in a warm, long autumn, no further development occurs, i.e., for the normal development of the chistyak, freezing of the tubers is required. From November to January, there is a winter dormant period, and in January, under the snow cover, the buds start to grow. Each shoot, which develops from a tuber, has the shape of a wedge that breaks through the ground thanks to a case of leathery, colorless leaves. At the end of January, shoots appear on the surface of the soil and the cover leaves stop growing. In March, the deployment of true leaves begins, and in mid-April, the stems reach 5-6 cm in length and have slightly green leaves and buds.

Flowers solitary on long stalks, actinomorphic, with double perianth. Calyx of three yellowish-green leaves, falling shortly after the flower opens. Corolla of 6-14 golden yellow glossy petals. At the base of the petal is a nectar fossa, covered with a small, bilobed scale. Stamens and pistils numerous. The chistyak has a lot of pollinators: its nectar is available for flies. Many spring insects feed on the yellow flowers of the chistyak: flies, bees, beetles, etc.

The flowers close at night. Petals close even in rainy weather. The pollen is protected from moisture. The reproductive organs of the flower do not suffer from night colds. The seeds of the chistyak are spread by ants.

In early spring, the chistyak can already find the beginnings of new tubers. At this time, they appear underground in the form of small outgrowths at the bottom of the stem. By the beginning of the flowering of the plant, they grow significantly. By the time the chistyak blooms, white outgrowths turn into new tubers that stand out sharply from last year's tubers. The tubers of the previous year also change, nutrients are spent on the development of the plant, and the tubers from hard ones become gradually soft, and later completely wrinkle and rot. For the next year, nutrients are deposited in new tubers.

Rice. 142. Chistyak spring ( Ficaria verna)

In the axils of the expanded petioles of the chistyak leaf, dirty yellow buds are formed, similar to tubers. They are filled with a supply of nutrients. When the chistyak fades and begins to wither, the buds fall out of the leaf axils. Rainwater streams can carry them far away from the mother plant; the chistyak settles. But many buds will remain in place, and due to them, the thicket of the chistyak is expanding.

The scales covering the shoots and rhizomes of the Peter's Cross are modified leaves. They have cavities that open outwards with narrow slits. It is believed that these cavities serve to evaporate water: special adaptations to the conditions of underground life. The flowers of the Peter's Cross are wrong. Insects pollinate - bumblebees, which provide cross-pollination. The stigma ripens earlier in the flower than the stamens, the anthers of which remain closed for a long time. At this time, flowers can be pollinated by pollen delivered by bumblebees from other more developed specimens. Then the stamens grow, and the style, previously hooked, straightens, due to which the stigma moves away from the anthers. At this stage, the arriving insect first meets the stigma on its way, and leaving a part of the brought pollen on it, reaches the anthers. These anthers are closed in the form of spines and, pushing them apart, the insect gets dirty in the pollen. If many flowers of the Peter's Cross remain unpollinated insects, then by the time they bloom, the column withers, the growing stamen filaments expose the anthers beyond the edge of the corolla, and the wind can transfer the pollen to the neighboring younger flowers of the same brush, with a pistil that has not yet withered. This is a kind of reserve in case the flowers were left unvisited by bumblebees and a sufficient amount of pollen was preserved in the anthers.

Petrov cross forms a large number of tiny seeds. The wind disperses them. Only a few of the seeds will give new plants: and not always the roots of the sprout reach the root of a living deciduous tree.

As noted above, in plants characterized by the ability to vegetate and bloom in early spring, there is a certain relationship between the rate of their development and the autumn preparation of wintering buds. Plants bloom earlier, in which there is a fully formed flower in the wintering bud.

In early spring, even people who are not familiar with botany pay attention to the early flowers of the coltsfoot (Fig. 143) ( Tusillago farfara), the Compositae family (Asteraceae), blooming even before the complete removal of the snow cover in early April, in the southern well-warmed, protected places. The coltsfoot is found everywhere. Inflorescences - baskets sit on thick pale green stems barely rising above the ground, covered with pinkish scaly leaves. The true leaves of the coltsfoot appear later. In the ground there are juicy fleshy rhizomes with a supply of nutrients formed by last year's leaves. There are small scales on the rhizome.

As soon as the snow melts, flower shoots rise from several rhizome buds. Usually coltsfoot blooms en masse immediately after snowfall. The inflorescences of the coltsfoot are fully formed at the end of summer and are located almost at the surface of the soil. Some botanists believe that the generative shoot formed last year ends its development in the spring. After flowering, new shoots grow from other buds of the rhizome, but without flowers, but with large green leaves. These leaves will synthesize organic substances during the summer, which will provide the plant with the opportunity to bloom next spring. In clear sunny weather, the inflorescences turn towards the sun, in the evening and in cloudy weather, the baskets droop, and the leaves of the wrapper straighten, so that the entire inflorescence closes. This contributes to the preservation of pollen, which has not yet had time to get enough sleep from cracked anthers. Flowers are pollinated by insects, nectar is secreted near the ovary, sticky pollen, stigmas ripen before anthers. The coltsfoot is the first honey plant and medicinal plant. When closing and opening a flower, self-pollination is possible.

Thus, the coltsfoot rhizome performs two functions: 1) as a receptacle for reserve nutrients; 2) an organ of vegetative propagation, they are located in several tiers, at different depths.

1 b

1a

Rice. 143. Mother and stepmother ( Tusillago farfara)

1 - leaves (on the upper side - on the right (b), on the lower side - on the left (a)), 2 - general view of a flowering plant, 3 - basket inflorescence, 4 - tubular flower, 5 - reed flower, 6 - fruiting basket, 7 - seed with tuft

In early spring, juicy reddish-brown spring spore-bearing shoots of horsetail ( Equisetum arvense) (Fig. 144). There is almost no chlorophyll in the spring shoot, it grows and forms spores due to the nutrient reserves of the underground shoot - rhizomes and nodules

cow on it. With the help of a simple experiment, an iodine reaction, you can make sure that the nodules of horsetail are rich in starch. Branches depart from the main underground rhizome, which give annual above-ground shoots. The roots emerge from the nodes of the underground axes and branch out strongly.

Rice. 144. Field horsetail ( Equisetum arvense):

1 - summer shoot, 2 - spring spore-bearing shoots with rhizome and nodules, 3 - sporophyll with sporangia, 4 - spores with unfolded elaters, 5 - stem node with fused leaves

Underground and aboveground stems consist of internodes hollow inside, separated from one another by transverse partitions. Spore-bearing shoots develop from autumn and only grow in spring; they end in a spikelet of sporophylls, i.e., modified leaves bearing sporangia. Sporangia have the appearance of hexagonal scales, on legs; they are located in close whorls and on the lower side they bear 5 sac-like sporangia, a single-layer wall, which bursts with a longitudinal crack when ripe. Mature spores are green in color, contain chlorophyll and are spherical or ovoid. The outer layer of their shell takes the form of two ribbons spirally curled around the body, which twist in moist air and straighten out in dry air; they are called springs or elaters and serve to hold the spores together; since spores produce unisexual outgrowths during germination, the adhesion of spores ensures the close proximity of female and male outgrowths, which is very important for ensuring fertilization. The sprouts are leaf-shaped, green, branched or dissected incorrectly, the male sprouts are smaller than the female ones. The growth develops antheridia and archegonia, similar to those of ferns.

Spore-bearing shoots of horsetail can be up to 30 cm in height, light reddish-brown in color with long internodes, whitish bell-shaped sheaths, with 8-12 lanceolate, sharp dark brown teeth; thickness of shoots from 3 to 5 mm. Spore-bearing spikelets 3.5 cm long with a clearly visible axis.

Barren horsetail shoots are furrowed, rough, with cylindrical, loosely fitting light green leafy sheaths, bearing 12-18 triangular-lanceolate blackish teeth with a white border.

Tuberous swellings form on underground shoots. Dig out the horsetail rhizome, examine and sketch.

Tasks and work order

I. Spring phenomena in the life of woody plants.

1. Determine the start date of sap flow in Norway maple and birch. The sap flow of Norway maple and birch is marked by the date when drops of sap first appear in 2-3 trees (adults) from a pre-made puncture or incision in the bark to the wood (at a height of 1.5 m on the south side). A puncture should be done at the beginning of March near a maple, in mid-March near a birch. To fix the sap flow, you need to visit these trees every day. After registering the beginning of sap flow, the hole must be covered with garden pitch or clay.

2. Mark the timing of bud swelling in different tree species.

3. Determine the date of the beginning and complete leafing of trees and shrubs. Foliation is marked by the date when in 2-3 plants of this species the first leaves appear on the shoots with a leaf blade already unfolded.

4. Highlight flowering trees and shrubs:

a) before the leaves open;

b) simultaneously with the blooming of leaves;

c) after the leaves open.

How to explain the flowering of wind-pollinated trees and shrubs before the leaves bloom?

d) the beginning of flowering: the day is noted when 2-3 specimens of this species have flowers with a fully opened corolla in insect-pollinated species or anthers in wind-pollinated species begin to dust;

e) mass flowering is observed when at least 50% of the plants of this species have blossomed;

f) the end of flowering is noted by the last 2-3 flowering specimens.

5. Identify ways to pollinate trees and shrubs.

6. To study the features of flowering of wind-pollinated flowers:

The formation of numerous staminate inflorescences swaying from the wind;

Abundant formation of dry and small pollen with a smooth shell (examine under a microscope);

The formation of unisexual flowers and inflorescences in monoecious and dioecious trees and shrubs;

The structure of staminate and pistillate flowers, weak development of perianths or its replacement by bracts, inconspicuous color of flowers, lack of nectar;

The formation of large, branched or hairy sticky stigmas that catch flying pollen;

Compare flowers and inflorescences of alder and hazel, poplar and Norway maple, birch and oak, sketch them;

Collect a collection - a herbarium of flowering branches of trees and shrubs.

7. Study the structure of staminate and pistillate flowers and inflorescences of various types of willow and sketch:

Track and describe the behavior of bees and bumblebees on willow flowers;

Collect a herbarium of flowering willow branches.

8. Consider and draw the structure of pistillate, staminate and bisexual flowers of Norway maple and note:

a) method of pollination;

b) what insects pollinate.

9. Considering the opening buds of the Norway maple, lilac, linden, apple tree, dog rose, establish the origin of the bud scales. Find out if all plants have kidney scales of the same origin (explanation in the text). Sketch the transition of kidney scales in maple, linden, apple, dog rose.

10. Consider the structure of the kidney and trace the growth of the shoot in length. Mark 5 shoots with labels or colored thread at the beginning of its emergence from the bud and measure with a centimeter ruler its growth in length in the beginning of spring after 3 days, and then 5, when it will be seen that the growth in length has almost stopped. It should be noted the duration (in days) of the growth of an elementary shoot in the spring, as well as the end date of growth in length.

11. Observe how the leaf blade grows and how long it grows. To do this, 5 leaves are taken under observation on the control shoots, immediately after they emerge they are marked with colored threads, a mesh is applied evenly on the plate with ink, after about 1 mm, and then an increase in the distance between the lines is observed daily.

You can measure the length of the petiole and leaf blade with a centimeter ruler. The data are recorded in the observation diary and then the duration of leaf growth in days is calculated. It is easy to verify that the increase in the size of the leaves occurs only for a short period of time, and the elongation of the petiole usually lasts longer than the increase in the size of the blade of the same leaf, which ensures the formation of a leaf mosaic.

12. Simultaneously with the observation of the growth of shoots and leaves, trace the change in color of the leaves after emerging from the bud and other adaptations to protect against the unfavorable phenomena of spring. To make a phenoherbarium of leaves of oak, hazel, maple, birch, where all changes in the shape, size, color and other features of the leaves that occur with age will be visible.

13. Find seedlings of various woody plants on the soil. Compare the cotyledons of maple, oak, mountain ash, linden with the leaves of the adult generation. Sketch the seedlings of the discovered trees.

II. Spring phenomena in the life of perennial herbaceous plants

1. Find out due to what conditions the under-snow development of plants occurs:

What is the condition of the soil in early spring (frozen, semi-frozen, thawed)?

What is the moisture content of the soil?

What is the surface temperature of the soil under the snow?

2. Carefully, in order not to damage the plants and seedlings, clear a 50 × 50 cm area of ​​snow and find out how the shoots of early spring plants germinate and come to the surface:

Draw seedlings of all types of plants, showing in the figure the forms of seedlings and all their organs, paying attention to the morphological features of the first leaves;

Describe the color of seedlings;

Mark the height of the seedlings, the number of leaves, pubescence, etc.

3. Determine what phase of flowering the plant is in at the moment. To disassemble the structure of flowers of herbaceous early-flowering plants: anemone, Kashubian buttercup, corydalis, goose onion, lungwort, hoof, coltsfoot, perennial forestry. Describe the structure of flowers and sketch the appearance; name the methods of pollination. Write formulas for flowers.

4. Observe the visiting of flowers of early-flowering herbaceous plants by insects:

Changing the color of the corolla in lungwort;

The phenomenon of heterostyly in lungwort and primrose;

Secretion of nectar at the base of the corolla of flowers;

Species of insects visiting the flowers of early-flowering ones;

Intensity of visits to pink and blue lungwort flowers. To do this, select 2 groups of observers, one - monitors pink flowers, the other - blue ones per unit time. Then the results are summarized and a conclusion is drawn.

5. To identify the cause of early flowering in herbaceous plants of a broad-leaved forest.

6. Describe and sketch the underground organs: rhizomes of the coltsfoot, hoof, hawk; a bulb in a goose onion, root tubers in a chistyak; corms in Corydalis.

7. Determine the species composition of early-flowering herbaceous plants of a broad-leaved forest.

III. Familiarize yourself with the structure and biology of horsetails.

IV. Identify early-flowering sedges and grasses and study the features of their structure.

Note. During excursions to observe seasonal changes, it is necessary to keep a diary. All field notes must be done carefully at the place of work with a simple pencil or ballpoint pen without drafts. For convenience, tie a pen, a magnifying glass on a cord and put it on your neck.

Phenophases are marked with the following icons:

Vegetation to flowering.

ˆ budding.

) flowering.

About full bloom.

(bloom.

Unripe fruits.

Vegetation after flowering.

Approximate scheme for describing a flower: type and type of inflorescence. Pediceled or sessile, regular (actinomorphic) or irregular (zygomorphic); bisexual or unisexual. Perianth simple or double. Calyx (Ca) 6th number, arrangement of sepals, separate, joint-leaved, pubescent, glabrous.

Corolla (Co): the number and arrangement of petals, separate and interpetal. Whisk shape. Coloring.

Androecium (A): number of stamens, their shape, location, free, fused.

Gynoecium (G): number of pistils, location in the flower. Receptacle (convex, flat, concave), ovary position (upper, lower, middle, etc.).

Adaptations for cross-pollination: heterostyly - heterocolumnar, wind-pollinated, insect-pollinated, self-pollinated.

To the question of early flowering plants pollinated by the wind, asked by the author Natalia Zubova the best answer is Early-flowering plants: buttercup anemone, oak anemone, spring nettle, dense corydalis, European hoof, coltsfoot, yellow goose onion, Siberian blueberry, drooping birch, gray obkha, aspen.
Pollinated by the wind: drooping birch, gray obkha, aspen.
The significance of early flowering lies in the fact that a lot of light is required for the formation of seeds,
so they bloom before the leaves on the trees.
In addition, the absence of leaves facilitates pollination, especially with the help of wind.

In plants pollinated by the wind, flowers are diametrically opposed to flowers that are pollinated by insects.
Wind is an elemental factor and can carry pollen in different directions.
To use it, plants need completely different flowers, as in insect pollination.
When pollinated by the wind, there is no need to spend valuable materials on the bright color of flower covers, on the formation of sweet nectar, fragrant aroma.
Other devices were developed here, aimed at simplifying the structure of the flower.
Therefore, the flowers of wind-pollinated (anemophilic) plants are inconspicuous, do not emit any odor, do not emit nectar. Their perianth is very poorly developed or completely absent. He is not needed here. On the contrary, the anthers extended far outward are freely fanned by the wind (cereals, sedges), which blows pollen out of them and disperses it through the air. Even a light breeze shakes catkins, panicles, stamens.
Our trees and shrubs (poplar, hazel, etc.) usually bloom in spring, when strong winds blow and the foliage has not yet blossomed, so that the wind blows pollen onto the flowers without hindrance. Wind-pollinated plants do not grow alone, but form large thickets, which also increases the chances of their flowers being pollinated. The wind scatters uselessly a lot of pollen, so plants produce it in huge quantities. For example, in an earring of an ordinary hazel, there are up to a million pollen cells. And when the pine blossoms, whole clouds of yellow pollen rise in the air, which settles on the ground in the form of the so-called sulfur rain. Pine dust particles also have special devices for flying in the form of two balloons. In general, all wind-pollinated plants have fine, light, dry pollen. Thanks to this, the wind easily blows it out of the anthers.
And the stigmas, in turn, are well adapted to trapping pollen. Like the anthers, during the flowering period they are exposed far outside and look like thick feathers (cereals), long threads (corn, sedge) or tassels (hazel).
With the help of wind in Central Europe, about 19% of plants are pollinated. Among them are such common trees and shrubs as spruce, pine, oak, alder, birch, aspen, elm, ash, hornbeam, and herbaceous plants - cereals, sedges and pondweeds growing in water. Wind pollination occurs in dry weather, while pollen does not spill out during rain.
en.wikipedia.org/wiki/Wind pollinated_flowers
link