Flowering plants. Families and names of medicinal plants

Division Angiosperms- the most highly organized plants that currently dominate the vegetation cover of the globe and number about 300 thousand species. Plants of this department are distributed everywhere: on all continents, in all climatic zones ah and in a wide variety of environmental conditions. They play the most important role in the formation of plant communities, with the exception of swamp and taiga communities. That is why they are called “winners in the struggle for existence.” Angiosperms are woody or herbaceous plants with well-developed, very diverse roots, stems and leaves.

The rich diversity of angiosperms explains their high adaptability to a variety of environmental conditions. Compared with gymnosperms and other departments flora Angiosperms are characterized by the following features:

1. the presence of a flower;
2. the presence of new organs such as pistil and fruit;
3. covering the seeds with pericarp (that’s why the department received the name “angiosperms”;
4. location of ovules in the ovary of the pistil;
5. double fertilization;
6. the development of the fruit from the ovary, and the seeds inside the fruit.

In life and economic activity Angiosperms are of much greater importance to humans than plants of other divisions.

All types of angiosperms (flowering) plants belong to two classes: dicotyledons and monocotyledons. Among them there are trees, shrubs and herbs, annual, biennial and perennial plants.

Classification of angiosperms

As noted above, in the department of angiosperms there are two classes: dicotyledons and monocotyledons. Considering their large number and diversity, separate families, genera, and species are distinguished in each class.

The dicotyledonous class unites over 175 thousand species, about 350 families. The division of angiosperms into families is based on the structure of flowers; The characteristics of inflorescences and fruits and, to a lesser extent, vegetative organs are also taken into account. The main characteristics of some families of the dicotyledonous class are presented in the table.

As you can see, the characteristic features of angiosperms and, in particular, representatives of two classes, lie in the structure of their organs and especially flowers, that is, vegetative and generative organs.

Origin of flowering plants. Flowering plants appeared on Earth in the Mesozoic era, during the Cretaceous period from gymnosperms. This happened 120-130 million years ago, the most likely ancestors of flowering ferns are considered to be a non-specialized group of seed ferns. Flowering plants are the largest and most highly organized department in the plant kingdom, uniting 250 thousand species out of 350 thousand species of all plants. The term angiosperms is probably not entirely appropriate - in gymnosperms, and even in pine, the seeds develop inside the cone and are quite well protected. But the appearance of a flower, which provides more reliable pollination, and a fruit, which protects the seeds and ensures their distribution, are the most important aromorphoses associated with the reproduction of flowering plants.

A flower is a short shoot with limited growth, just like the cone of a gymnosperm. Wind is sufficient for pollination of gymnosperms, but tropical forest Wind pollination of plants in lower tiers is difficult. Perhaps it was there that the first appeared flowering plants. Most scientists believe that the flower originated from the bisexual cone (strobilae) of ancient extinct gymnosperms. This strobillar, or evanth hypothesis. This hypothesis is confirmed by the finds of ancient gymnosperms - Bennettites, which had bisexual strobili, microsporangia with microspores (future stamens) were formed on microsporophylls, ovules with megasporania (future pistils) were located on megasporophylls. To protect the ovules, the female spore-bearing leaf (megasporophyll) folds and forms a closed container for the ovules - the carpel.

In the most primitive modern flowering plants - magnolia the flower still looks like a gymnosperm cone - numerous carpels, stamens, petals and sepals are arranged in a spiral on an elongated conical receptacle.

Structure. The conducting system is the most perfect; real vessels (trachea), are formed in the phloem sieve tubes with companion cells.

The structure of the photosynthetic apparatus - the leaves - becomes more complex; the leaves are simple and complex; the flattened shape of the leaves significantly increases the surface area and efficiency of photosynthesis.

Reproduction. The life cycle is dominated by the heterosporous sporophyte, which is a leafy plant; the gametophyte is extremely reduced (male - to the pollen grain, female - to the embryo sac); archegonia and primary endosperm are absent in the female gametophyte and antheridia in the male one. Reduction of gametophytes has great value– they develop very quickly (in gymnosperms it takes two to three years from pollination to fertilization). The absence of primary endosperm in the female gametophyte of flowering plants was compensated by the second fertilization and the formation of triploid nutritional tissue - endosperm - in the seed.

The organ of asexual and sexual reproduction is the flower; due to idioadaptations, flowers appear that are pollinated by wind, water, self-pollinating, pollinated by insects and other animals. The appearance of a flower facilitates the pollination process. The ovules are small, protected by the walls of the ovary. Fertilization does not depend on the presence of water; double, after which not only a diploid embryo is formed, but also a triploid endosperm. After fertilization, seeds are formed that have an embryo, a reserve nutrients and peel, they are protected by pericarp tissues from external influences, subsequently the pericarp ensures the dissemination of seeds in one way or another.

Manifold. Plants of the department Flower taxonomy are divided into two classes - dicotyledons and monocotyledons; the main characteristic is the number of cotyledons in the seed embryo. Plants of the Dicotyledonous class are considered more ancient plants; their flowers are more primitive. Primitive features in the structure of a flower are considered large number flower elements (stamens, pistils, petals), double perianth, unfused flower elements (sepals, stamens), regular flower shape. Woody life forms– are also considered primitive characteristics. Specialization of a flower in relation to a particular group of pollinators, reduction or fusion of flower elements, herbaceous life forms and wrong flower are considered progressive signs.

Monocots evolved either from one of the groups of primitive dicots in the early stages of dicot evolution, or perhaps from different groups primitive dicotyledons.

Characteristics of classes of flowering plants. The distinctive features of dicotyledonous and monocotyledonous plants are summarized in table. 1 and fig. .

Table 2. The most important distinguishing features of monocots and dicotyledons:

Dicotyledonous plants. The dicotyledonous class unites about 200,000 species, grouped into 280 families, which in turn are grouped into orders. Out of 280 families, consider the characteristics of five families school curriculum.

Family Cruciferous. About 3000 species, mostly annual, biennial and perennial herbaceous plants, rarely subshrubs (Fig. 74). This family includes plants with flowers, the formula of which is *Ca 2+2 Co 4 A 2+4 G (2) and fruits - pods, or pods.

Leaves simple, without stipules; leaf arrangement is alternate, sometimes the leaves are collected in basal rosettes.

Flowers bisexual, regular (actinomorphic). The perianth is double, four-membered. A calyx of four free sepals, a corolla of four free petals, arranged crosswise and alternating with the sepals. There are six stamens, in the outer circle there are two short ones, in the inner circle there are four long ones (androecium quadruple). There is one pistil, formed by two carpels, the ovary is superior. The flowers are collected in simple and complex racemes.

Fetus – a pod or pod.

Meaning. A large number of vegetable, oilseed, ornamental, fodder and honey species. Eat medicinal species(shepherd's purse, jaundice, meadow heart). There are a lot of malicious weeds in fields and gardens (colts, jarutka, shepherd's purse).

In the Mediterranean, you can still find wild cabbage, which has been cultivated for about 5,000 years.

The Slavs have been growing cabbage since the 9th century, they invented a method for fermenting it, and the absence of heat treatment preserves the entire complex of vitamins - C, K, P, B1, B2 and others; cabbage contains a whole complex of essential microelements.

Cruciferous vegetables include turnips, which were the second bread before potatoes, radishes, and a variety of radishes - radishes. Mustard is used as a spicy seasoning, mustard oil is used as food, and horseradish is also used as a seasoning. The most productive oilseed plant temperate latitudes– rapeseed, its oil is used in the technical industry. Of the ornamental cruciferous plants, the most famous are gillyflowers. night beauty.

Family Rosaceae. Up to 3500 species, life forms - trees, shrubs and herbs (Fig. 75). This family includes plants with flowers, the formula of which is *Ca 5 Co 5 A ∞ G ∞ or *Ca 5 Co 5 A ∞ G 1 , there are Rosaceae and other flower formulas. The fruits are very diverse - nuts, capsules, drupes, polydrupes, apples, strawberries.

Leaves both simple and complex, with stipules (sometimes falling off early). Leaf arrangement is alternate, less often opposite.

Flowers usually regular (actinomorphic), bisexual. The perianth is double, five-membered. The calyx has five sepals (free or fused at the bases), the corolla has five (less often four) petals, always separate. Sometimes there is a subchasha. There are usually an indefinite number of stamens, arranged in circles of five to ten. One pestle or many. The ovary is inferior, semi-inferior or superior. One of the features of the flower is the presence of hypanthium in the form of a saucer, bowl or glass. Flowers are often collected in inflorescences: a raceme, a panicle, a simple umbrella, a corymb and others.

Diverse and fruit . In spirea - a leaflet or capsule, in pink - a multi-nut or multi-drupe, in apple - an apple, in plum - a drupe.

Meaning. Among the rosaceous plants there are many fruit and berry crops, medicinal and ornamental plants. Cherry, apricot, plum, strawberry, sweet cherry, raspberry, apple tree, pear, quince, cherry plum - all these are fruit and berry crops Rosaceae. Many medicinal plants(rose hips, common raspberries, cinquefoil erect, burnet, bird cherry, etc.). The petals of some types of roses are used to obtain rose oil. Among decorative flowers, roses come first, of course; currently about 25,000 varieties of roses are known.

Family Legumes (or Papilaceae). About 18,000 species, perennial and annual herbs, less commonly trees, shrubs, vines (Fig. 76).

This family includes plants with flowers, the formula of which is Ca (5) Co 1+2+(2) A (9)+1 G 1 or Ca (5) Co 1+2+(2) A (10) G 1 , there are legumes with other flower formulas. The fruit is in moth beans.

Feature legumes – the presence of nodules on the roots , resulting from symbiosis with nitrogen-fixing nodule bacteria.

Leaves Trifoliate, pinnately and palmately compound, less often simple, with stipules, alternate leaf arrangement.

Flowers zygomorphic (irregular), bisexual, moth-like. The calyx consists of five fused sepals; corolla five-petalled, “moth” type: the largest, the upper petal - sail or flag, two side – wings or oars, the two lower ones have fused into boat. There are ten stamens, one pistil, formed by one carpel. Ovary superior.

Flowers are often collected in inflorescences of a raceme, head, spike, and sometimes solitary. Fetus - bob

Meaning. Among the moths there are many food plants (beans, peas, lentils, beans, soybeans, peanuts). Vetch, alfalfa, china, clover are excellent forage plants. Licorice, kale, gorse, sweet clover and many others are used as medicinal plants. Sophora japonica reduces capillary fragility.

As a result of a symbiotic relationship with nodule bacteria, they accumulate nitrogenous substances in the soil; seeds and green mass contain large amounts of protein. For these features, legumes received the names “vegetable veal” and “living fertilizers.” When plowing green legumes into the soil, they enrich it with nitrogen compounds available to other plants. Therefore they are used as green fertilizers (sederates) . Lupine is considered the best sederat; plowing it enriches the soil with nitrogen up to 200 kg per hectare.

Available decorative types– lupine, sweet pea, wisteria, robinia (white acacia), caragana (yellow acacia), silver acacia, which in everyday life is called mimosa.

Family Solanaceae. About 3000 species, mostly herbaceous plants, occasionally tree-like forms - subshrubs, shrubs, trees (Fig. 77). Unites plants whose flower formula is *Ca (5) Co (5) A 5 G (2) , the fruits of which are berries or capsules.

Leaves simple, with a whole or dissected leaf blade, without stipules. The leaf arrangement is regular.

The flowers are bisexual, five-membered, regular. Perianth double, formed by a calyx of five fused sepals and a corolla of five fused petals. Androecium : There are usually five stamens. They alternate with the teeth of the corolla and grow to its tube. Gynoecium : one pistil, most often formed by the fusion of two carpels (coenocarpous), the ovary is superior.

Inflorescences : flowers are often collected in curled or solitary inflorescences. Fetus - box, berry.

Meaning. All nightshades are poisonous because they contain different alkaloids.

This family includes vegetables (tomato, eggplant, pepper, potato, tobacco). Potato or tuberous nightshade is a perennial herbaceous plant that is cultivated as an annual. Homeland – South America. Potatoes arrived in Europe in 1565; the French agronomist Antoine Parmentier appeared at a ball with a bouquet of potato flowers. The king liked the overseas flower, and potatoes became a fashionable ornamental crop. In order to put potatoes into practice agriculture Parmentier proposed placing armed guards around the fields, which were removed at night. Peasants began to steal protected crops and grow them in their fields.

Potatoes came to Russia with the help of Peter I; he sent a bag of potatoes, having tried potato dishes in Holland. However, the introduction of potatoes in Russia met with strong resistance and even “potato riots.” Firstly, the church took up arms against potatoes, calling it “the devil’s apple,” and secondly, at first, peasants and sometimes nobles ate potato fruits - green, tomato-like berries that caused poisoning, even death. But the potatoes optimal conditions cultivation allows you to get 2-3 times more dry matter per unit area than grain crops.

Plants of the Solanaceae family contain a large number of different alkaloids, so among them there are many poisonous and medicinal plants (henbane, datura, belladonna). The anesthetic and antispasmodic effects of Datura allow it to be used in the treatment of stomach and intestinal ulcers, gallbladder diseases, and bronchial asthma.

Among the ornamental nightshades, the most famous are hybrid petunia, fragrant tobacco, and physalis. Real tobacco and shag tobacco are industrial crops. Some nightshades (black and red nightshade) are weeds.

Family Asteraceae (or Asteraceae). The most big family class Dicotyledons, numbering about 25,000 species. Presented by perennial or annual herbs, in the tropics there are subshrubs, less often shrubs, vines or small trees (Fig. 78). This family includes plants whose flowers are always collected in an inflorescence. basket, fruit – achene.

Leaves simple, whole or dissected, without stipules. The leaf arrangement is alternate, less often opposite or whorled.

Flowers , as a rule, small, regular or irregular, bisexual, unisexual or asexual. The perianth is double, but there is no typical calyx; the sepals have turned into hairs that form a pappus. The corolla is five-membered, fused-petalled. There are five stamens, fused with anthers, and one pistil. There are four types of flowers (Fig. 79):

tubular flower. The perianth is double, the flower is regular (actinomorphic). The calyx is poorly developed and often has the appearance of a tuft. The petals of the corolla grow together into a tube. Flower formula *Ca 0-∞ Co (5) A (5) G (2).

reed flower. The perianth is double, the flower is irregular. The calyx is poorly developed, in the form of a tuft or denticles. The petals of the corolla grow together. A short tube is formed in the lower part, which is split on one side and forms a tongue on the other, ending with five cloves. The flower is bisexual, flower formula Ca 0-∞ Co (5) A (5) G (2).

False-lingulate flower. The corolla consists of three fused petals (two are reduced), has the appearance of a more or less long tongue ending with three teeth. These flowers are often pistillate, sometimes asexual. Flower formula Ca 0-∞ Co (3) A 0 G (2).

funnel flower. The corolla is shaped like a funnel. Asexual flower, used to attract insects. Flower formula Ca 0-∞ Co (5-7) A 0 G 0.

The most characteristic feature of the plants of the family is the simple inflorescence basket , the lower part is a basket, the bottom of the inflorescence is surrounded by an involucre and green leaves. The baskets can be collected into complex inflorescences of a corymb or panicle. Fetus - achene. In dandelion, fruit development occurs parthenogenetically - without fertilization. This phenomenon is called apomixis.

Among the Asteraceae there are food (Jerusalem artichoke), oilseed (sunflower), forage (wild lettuce), melliferous (elecampane), medicinal (coltsfoot) and ornamental (dahlias, asters, etc.) plants. Many are weeds (wormwood, thistle, thistle, bitterling).

Monocots. The class Monocots includes 80-85 families and about 64,000 species. Life forms are mainly annual, biennial and perennial herbs. But there is small quantity woody forms - trees, shrubs, vines. From this class we will consider two families of the school curriculum - lilies and cereals.

Liliaceae family. About 1300 species, perennial rhizomatous, corm or bulbous herbaceous plants (Fig. 80).

Leaves simple, entire, with parallel veins, often sessile, vaginal. The leaf arrangement is regular.

Flowers correct, bisexual. The perianth is simple, corolla-shaped, six-membered, fused or sepate. There are six stamens. One pestle. Flowers are often collected in inflorescences: raceme, panicle, spike, umbel, and less often solitary. The formula of most flowers is *P 3+3 A 3+3 G (3).

Fetus - box, berry.

Among the linear ones there are many beautifully flowering ornamental plants: lily, tulip, hazel grouse, hyacinth, scylla.

Family Poagrass (or Poaceae). About 10,000 species are known, mostly perennial, less often annual or biennial herbs. Only representatives of the Bamboo subfamily have a lignified stem (but not capable of secondary thickening). These are cosmopolitan plants, that is, species found in most of the inhabited areas of the Earth. By species diversity cereals are second only to orchids and asteraceae (about 25,000 species).

Root system, like all monocots, it is fibrous; it is interesting that in most cereals (wheat, rye) several primary roots are formed at once.

Stem – straw, cylindrical, segmented, with well-defined nodes and hollow (less often solid) internodes. Typical for cereals tillering– branching below and above the soil surface.

Leaves simple, vaginal. The leaf blade consists of a sheath, leaf blade and ligule, with parallel venation. Sprouting leaves pierce the soil with the hard top of the first leaf, which has the shape of a cap and is called coleoptile. The leaf arrangement is regular.

Flowers highly reduced, bisexual, rarely unisexual, spikelets collected in inflorescences, which in turn form complex inflorescences: a complex spike, a panicle, a false spike (sultan), less often an ear. Each spikelet is a shortened inflorescence, at the base of which there are two glumes (modified leaves), often ending in awns. The flower consists of two lemmas, two floral films - lodicules, three stamens and one pistil with two feathery stigmas (Fig. 81). One of the flower formulas P (2) + 2 A 3 G (2) . Inflorescences - a complex spike, panicle, ear or brush.

Fetus – the pistil of cereals consists of 2 carpels, but one of them is reduced, resulting in a pseudomonocarp fruit grain.

Meaning . Wheat, rye, barley, oats, corn, rice, sugar cane form the basis of our diet. Wheat is one of the oldest cultivated plants, cultivated for about 10,000 years. All species (about 30) are annual herbaceous plants. The inflorescence is a complex spike; most cultivated wheats are self-pollinators. Durum varieties wheat contains 20-26% protein and is used to make pasta. Soft wheat varieties contain 11-15% protein and are used to make baked goods. Spring varieties are sown in spring, winter varieties - in autumn.

Among the cereals there are many forage plants - wheatgrass, fescue, bromegrass, bluegrass, foxtail, timothy, etc. Some grains are used in the textile and chemical industries, and in construction. Many weeds– wild oats, wheatgrass, chicken millet, etc. Some grains are used as medicinal plants.

Key terms and concepts

1. Evant theory. 2. Trachea. 3. Sieve tubes. 4. Gametophytes of flowering plants. 5. Sederats. 6. Flowers and fruits of cruciferous vegetables. 7 Flowers and fruits of Rosaceae. 8. Flowers and fruits of legumes. 9. Nightshade flowers and fruits. 10. Flowers and fruits of Asteraceae. 11. Flowers and fruits of lilies. 12. Flowers and fruits of cereals.

In the plant kingdom, the most numerous and advanced group is the department of Angiosperms. In this article we will introduce you to the general characteristics and significance of representatives of these plants and tell you about their structural features.

Origin

Known to be covered seed plants originated from a group of algae that have not survived to this day. It was they who founded the development of seed ferns, from which gymnosperms and angiosperms originated.

Angiosperms have another name - flowering plants, which they received due to the presence of the main reproductive organ - the flower.

The first remains of flowering representatives date back to the early Cretaceous deposits. In the second half of the Cretaceous period of the Mesozoic, angiosperms occupied a dominant position on the planet.

Main features

This type of flora has a variety of forms: trees, bushes, grasses. They are widespread in all natural areas. Their structure consists of a root system, stem, leaf and flower, from which the fruit and seed are formed.

Rice. 1. Plant forms.

The presence of a pericarp around the seed, which ensures their preservation and distribution, is a feature of angiosperms. In addition, the main features of this department are:

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• the presence of a flower;
• the ovary and fruit retain ovules and seeds;
• can be pollinated by water, wind, birds and insects;
• the female prothallus is presented in the form of an eight-nucleate embryo sac;
• male - in the form of a pollen grain, which consists of two types of cells: vegetative and generative;
• double fertilization: sperm fertilize the egg and the nucleus of the embryo sac;
• The life cycle is a change of generations.

The development cycle of a fertilized flower continues with the following transformations: the ovary turns into a fruit, the ovule into a seed, the zygote into a seed embryo, the secondary nucleus into a secondary endosperm, which has a triploid set of chromosomes.

Rice. 2. Flowering plant.

The flowering plant division is divided into two classes: Monocots and Dicotyledons.

The name mono- and dicotyledons is due to the presence of the number of cotyledons.

The distinctive features of the classes can be studied in the following table:

Rice. 3. Characteristic features of monocots and dicotyledons.

Cereals

The stems (straws) are mostly simple, cylindrical, separated by nodes. The leaf is linear or lanceolate. The flower is collected in a spike in the form of small yellowish-green spikelets. Examples of angiosperms of this family are wheat, rye, oats, sugar cane, corn, bamboo and others.

Liliaceae

Perennial species have bulbs as roots. The flower is bisexual, the perianth is corolla-shaped from free (unfused) petals. The fruit is in the form of a berry or capsule. This family includes: onions, garlic, lilies of the valley, aloe, tulips, lilies and others.

Rosaceae

They have a special receptacle structure. The fruit is presented in the form of a nut or drupe. Pollinated by insects. Representatives: roses, strawberries, raspberries, plums, cherries, pears, apple trees and others.

Legumes

A special feature is the erect, curly stems. The structure of the leaves is complex; they have stipules. The flower consists of 5 sepals, the corolla has five petals. Bean-shaped fruit. Plants are pollinated by insects. Legumes include: peas, clover, soybeans, beans, alfalfa and others.

Solanaceae

The peculiarity of the structure is regular simple leaves with a whole or dissected plate. The corolla is tubular to which the stamens are attached. The fruit is represented by a berry or a capsule. Representatives: potatoes, nightshade, eggplant, tomatoes, peppers, dope.

Cruciferous

The flowers of the plants are presented in the form of racemose inflorescences. The sepals and petals are crosswise. There are 6 stamens: four long and two short. The fruit is in the form of a pod. Example: radish, cabbage, shepherd's purse, mustard, matthiola.

Compositae

A distinctive feature is the inflorescence of the basket, at the bottom of which there are small flowers. The fruit is an achene with a tuft or crown. Representatives: sunflower, asters, dandelion, chamomile, cornflower.

Flowering plants are used:

• in the food industry;
• in medicine and pharmacology;
• as technological and feed crops;
• V landscape design.

What have we learned?

Numerous representatives of the plant kingdom are angiosperms. Their peculiarity is the presence of a flower, which serves as a reproductive organ. Depending on the number of cotyledons in the embryo, flowering plants are divided into monocotyledons and dicotyledons. All of them are widely used in nutrition, treatment, and landscape design. We also studied in detail the properties of each family.

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Angiosperms are the most advanced and most numerous group of the modern plant world.

Flowering plants evolved from a group of extinct algae that gave rise to seed ferns. Thus, gymnosperms and angiosperms are parallel branches of evolution, having a common ancestor, but then evolving independently of each other. Remains of the first flowering plants are found in Early Cretaceous sediments.

Starting from the end of the Cretaceous period of the Mesozoic era, angiosperms began to dominate the Earth, which acquired a number of advantages over other higher plants, including gymnosperms. The same period accounts for the greatest distribution of insects, birds and mammals, which are interconnected by food chains, adaptations to reproduction and living in the same environmental conditions. The life forms of angiosperms are represented by trees, shrubs or herbs, which determines their greatest ecological plasticity and distribution on land in all natural zones and water basins. Their main vegetative organs are the root, stem and leaf, which have numerous modifications and are the most specialized in structure and function.

Angiosperms, like gymnosperms, reproduce using seeds, but their seeds are protected by the pericarp, which contributes to their better conservation and distribution. And the appearance of a flower - an organ seed propagation, which (in general) gives rise to a new generation (reproduction), places this plant division in the position of the most highly organized representatives of the plant kingdom.

The morphological diversity of flowering plants is very large. The structure of their vegetative and generative organs reaches the greatest complexity; the tissues are characterized by a high degree of specialization.

Flowering plants are the only group of plants capable of forming complex multi-layered communities.

The department of angiosperms is divided into two classes - dicotyledons and monocotyledons.

DISTINCTIVE FEATURES OF ANGIOSPERMS (T.L. Bogdanova. Biology. Assignments and exercises. A guide for applicants to universities. M., 1991)

1. The presence of a flower.
2. The presence of an ovary and a fruit that preserves ovules and seeds.
3. Pollination by wind, insects, water, birds.
4. The female prothallus is an eight-nucleate embryo sac without archegonia.
5. The male prothallus is a pollen grain (pollen), consisting of two cells - vegetative and generative.
6. Double fertilization: one sperm fertilizes the egg, the other - the secondary (central) nucleus of the embryo sac.
7. Double fertilization ends with the following transformations: a fruit is formed from the ovary, a seed is formed from the ovule (ovule), a seed is formed from the zygote (diploid), and a secondary endosperm is formed from the fertilized secondary nucleus.
8. The endosperm is represented by tissue with a triploid set of chromosomes. It is formed simultaneously with the embryo of the seed; reserve nutrients (proteins, carbohydrates, fats) are deposited in it.
9. During germination, as soon as water enters the seed, its swelling begins, reserve substances turn into soluble forms available for absorption by the embryo. Some of the reserve substances of the endosperm are broken down by respiratory enzymes. which releases energy (in the form of ATP) necessary for the growth of the embryo.
10. Triploidy of the nuclei of endosperm cells, which carry hereditary information from maternal and paternal organisms, increases fitness young plant To different conditions environment.
11. From the seed embryo grows a sporophyte (asexual diploid generation), which can be represented by various life forms - grass (annual or perennial), shrub, tree, liana. Any life form of a plant has basic organs - root, stem, leaves and their modifications, as well as flowers, seeds, fruits.

Class Monocots

The name of the class “monocots” is due to the fact that the seed embryo contains one cotyledon. Monocots differ significantly from dicots in the following characteristics: 1) fibrous root system, the root has a primary structure (it lacks a cambium); 2) leaves are mostly simple, entire, with arcuate or parallel veins; 3) the vascular bundles in the stem are closed, scattered throughout the entire thickness of the stem.

Family Cereals (over 6 thousand species)

Biology of the family: herbaceous plants (with the exception of bamboo). The stems are simple, sometimes branched, cylindrical or flattened, separated by nodes. Most plants are hollow at the internodes and filled with tissue only at the nodes. Such a stem is called a straw. The leaves are linear or lanceolate, with a sheath at the base. At the junction of the vagina and the plate there is a growth - a tongue, the shape of which is a sign when identifying cereals. The flowers are yellowish-green, small, collected in inflorescences, spikelets that form a spike, raceme, panicle. At the base of each spikelet two glumes are attached, covering the spikelet. There are 2–5 flowers in a spikelet. The perianth consists of two floral scales, two films. The bisexual flower contains three stamens and a pistil with two feathery stigmas. In some cases, there are 1–6 spikelets and floral scales, 2–6, rarely 40 stamens. The fruit is a grain (nut or berry). Economic importance: 1. Wheat, rye, barley, oats, corn, rice, sorghum, mogar, sugar cane - grain, industrial crops (receive sugar, alcohol, beer). 2. Fescue, bluegrass, timothy - forage grasses. 3. Reed, bamboo. The stems are used in construction, to produce paper, as fuel. Cereals are widely used to stabilize sand, slopes, and in decorative floriculture. 4. Creeping wheatgrass, wild oat grass, bristle grass, and barnyard grass are weeds.

Liliaceae family (about 2800 species)

Biology of the family: one-, two- and perennial herbs, subshrubs, shrubs into trees. Perennial herbs are characterized by the presence of bulbs or rhizomes. The flowers are bisexual, less often unisexual. The perianth is mostly corolla-shaped, sometimes cup-shaped, consisting of free or incompletely fused leaves. The number of stamens corresponds to the number of perianth leaves. One pestle. The fruit is a three-lobed capsule or berry. Economic importance: 1. Onions, garlic, asparagus - vegetable crops. 2. Lily of the valley, aloe, hellebore - raw materials for medicines. 3. Lily, lily of the valley, tulip, hyacinth – ornamental crops.

Class dicotyledons

A systematic feature of dicotyledons is the presence of two cotyledons in the embryo. Distinctive Features dicotyledons are as follows: 1) tap root system, with developed lateral roots; 2) the root and stem have a secondary structure, there is a cambium; 3) vascular-fibrous bundles of the stem are open, arranged concentrically; 4) leaves, both simple and complex; 5) flowers of five- and four-membered types; 6) the endosperm in ripened seeds is well expressed in a number of species: Solanaceae, Apiaceae, etc. But in legumes, Asteraceae, etc. others (for example, peas, beans, sunflowers), are poorly developed or completely absent and reserve nutrients are located directly in the cotyledons of the embryo.

Rosaceae family (about 3 thousand species)

Biology of the family: distributed in countries with subtropical and temperate climate. Very diverse in the structure of the flower, inflorescences, fruits and leaves. A characteristic feature is the peculiar structure of the gynoecium and receptacle. The latter tends to grow. In some plant species, the parts of the flower that surround the pistil are fused at their bases and form a fleshy cup, the hypanthium, with the fused receptacle. Flowers with a double five-membered perianth, many stamens, they are arranged in a circle (their number is a multiple of 5), one or several pistils. The ovary is superior, inferior or middle. The fruits are drupes, nuts, often false or mixed. Insect-pollinated plants. Economic importance: 1. Rosehip. The fruits contain a lot of vitamin C, 1–8% sugar, up to 2% starch, 1–5% nitrogenous substances. The roots are rich in tannins. Used in the food (medicines) and perfume industries. 2. Roses (anthus, tea), raspberries, strawberries, apple trees, pears, rowan berries, plums, cherries, apricots, peach, almonds - ornamental crops, used in the food, perfume, and pharmaceutical industries.

Legume family (about 12 thousand species)

Biology of the family; stems erect, climbing, creeping. The leaves are compound with stipules. The structure of the flower is typical: a calyx of 5 sepals (3+2), a corolla of 5 petals (the back one is the sail, the two lateral ones are the vela, the two lower ones are fused at the top - the boat). There are 10 stamens (9 of them grow together and form an open tube). One pestle. The ovary is superior, unilocular. The fruit is a bean. Pollinated by insects. Economic importance of members of the family (astragalus, camel thorn - subshrub, vetch, peas, clover, alfalfa, beans, soybeans, lupine): food, fodder, melliferous, ornamental plants. Thanks to nodule bacteria, green manure. Nutritional and feed quality is reduced due to the concentration of glycosides (glycyrrhizine, coumarin, ononine) and alkaloids (cytisine, sparteine). They play a significant role in the formation of vegetation cover.

Family Solanaceae (about 2200 species)

Biology of the family: herbs, less often subshrubs, shrubs. Leaves are alternate, without stipules. Simple, with a whole or dissected plate. Flowers are correct or incorrect. The corolla is fused-petalled, tubular. There are 5 stamens attached to the corolla tube. There is one pistil with an upper two-locular ovary, which contains numerous seed germs. The flowers are bisexual. Insect-pollinated plants. The fruit is a berry or capsule (rarely drupe-shaped). Most nightshades contain poisonous alkaloids, which are used in small doses to produce medicines. Economic importance: 1. Nightshade (black nightshade). It is obtained from the leaves citric acid, drugs, from tobacco seeds - tobacco oil. 2. Potatoes, eggplants, tomatoes, peppers. Used in the food industry. Z. Belladonna (belladonna), scopolia, datura, black henbane are medicinal plants.

Family Cruciferae (about 2 thousand species)

Biology of the family: one-, two-, perennial herbs, subshrubs with alternate leaves, sometimes collected in a basal rosette. The flowers are bisexual, collected in racemes. The perianth is double, four-membered. Sepals and petals are arranged crosswise. There are 6 stamens, 4 of them are longer, 2 are shorter. One pestle. The fruit is a pod or pod. The seeds contain 15–49.5% oil. Economic importance: 1. Wild radish, shepherd's purse, field mustard, jaundice - weeds. 2. Cabbage, radish, turnip, rutabaga - garden crops. 3. Mustard, pane – oilseeds. 4. Levkoy, night beauty, matthiola - ornamental plants.

Family Asteraceae (about 15 thousand species)

Biology of the family: annual and perennial herbaceous plants, subshrubs, shrubs, small trees. Leaves are alternate or opposite, without stipules. A typical feature is a basket inflorescence. Individual flowers are located on the flat or convex bottom of the basket. The basket has a common involucre consisting of modified apical leaves. Typical flowers are bisexual, with a lower ovary, to which a modified calyx is attached, a corolla ligulate, tubular, funnel-shaped; the color is white, blue, yellow, light blue, etc. Flowers are unisexual (male or female), the outermost flowers are often sterile. There are 5 stamens, they grow together by dust particles into a tube through which passes a style bearing the stigma. The fruit is an ordinary achene with a hairy pappus, or membranous crown.

Cross-pollination or self-pollination

Economic importance: 1. Lettuce, chicory, artichoke - food crops. 2. Sunflower is an oilseed crop. 3. Jerusalem artichoke – forage crop. 4. Dandelion, wormwood, string, yarrow, chamomile are medicinal plants. 5. Dahlias, marigolds, chrysanthemums - ornamental plants, 6. Euphorbia thistle, cornflower, blue, creeping bitterweed - weeds.

Table. Department of angiosperms (T.L. Bogdanova. Biology. Assignments and exercises. A guide for applicants to universities. M., 1991)

Table. Comparative characteristics of the families of the angiosperm department ((T.L. Bogdanova. Biology. Assignments and exercises. A guide for applicants to universities. M., 1991)

Ecology of angiosperms

Currently, the dominant angiosperms on Earth are the youngest and most numerous plants. They passed their evolutionary path in those living conditions that were characteristic of the end of the Mesozoic and Cenozoic, i.e., in an environment close to modern. Therefore, their structure and life activity are most consistent with the environmental conditions of various natural and climatic zones globe and the established more ancient flora and fauna. Of all plants, angiosperms are the most widely distributed, both in natural places habitat and in agricultural conditions. The evolution of mammals, birds, and insects is largely connected with flowering plants, and they are not only food and habitat for each other, but also in many ways a means for survival and reproduction. Thus, raspberry seeds germinate better if they pass through the digestive tract of a bird that eats the fruit of this plant. Herbivores, feeding on grass, fertilize the soil with their excrement, creating better conditions for the life of these same grasses. Insects, feeding on pollen and nectar of flowers, contribute to cross pollination plants. But at the same time, giant swarms of locusts are destroying vast fields; herds of goats completely knock out plants by the roots, leaving bare wastelands. As a result of such interactions in nature, the number of a population increases and then sharply decreases, which applies equally to locusts and goats, since they themselves are subsequently left without food and die.

Angiosperms, together with gymnosperms, create the human habitat - these are the “green lungs” of the Earth, this is the integrity of our nature, its beauty, uniqueness, this is the food and health of people, both spiritually and physical sense. However, forest fires, deforestation, trampling, gas pollution, radiation exposure, drainage, and flooding change the face of the planet and pose a threat to human existence. The scientific and technological revolution has brought unforeseen changes to natural environment. The ecological balance of the Kola Peninsula, the Tyumen north, and the environs of the lake is deeply disturbed. Baikal. The Aral Sea and the lake are dying before our eyes. Balkhash. The taiga in the European part of Russia has almost been cut down. All people of the Earth, and our country in particular, must remember this, and now the future depends on each person, on his attitude towards nature.

It is perhaps simply impossible to list all angiosperms. And it will be quite difficult to name the species that are most important in nature and human life. After all, these plants have long acquired great practical importance, and their representatives are known as food, industrial, ornamental and fodder crops. What characteristics does the Angiosperms department have? The general characteristics and significance of these plants will be discussed in our article. So let's get started.

Biology: department Angiosperms

All seed plants have a number of structural features that make them dominant on Earth. All of them arose in the process of evolution as a result of adaptation of organisms to changing conditions environment. The Angiosperms department, according to taxonomy, currently numbers more than two hundred and fifty thousand species. While their predecessors - the Gymnosperms department - are only eight hundred.

The main characteristics of the Angiosperms department:

Presence of a flower;

Formation of the fetus;

Development of the embryo inside the seed germ;

Double fertilization;

The presence of a seed surrounded by a pericarp.

Taken together, all these characteristics determine the advantages thanks to which representatives of the Angiosperms department were able to spread across the planet, mastering the conditions of different climatic zones and zones.

Holo- and Angiosperms: similarities and differences

But let's go back to basics. All seed plants are grouped into two divisions: Holosperms and Angiosperms. Copies of the first systematic group These are mainly represented by plants with a predominant woody life form, with a taproot system. The foliage is represented by thin leaves - needles. Thanks to them and the presence of resin passages, which prevent the process of excessive evaporation, these plants remain evergreen throughout all seasons. But the main feature of this section is the absence of flowers, and therefore fruits. Their seeds are located openly on the scales of the cones; they are not protected by anything. Therefore, the likelihood that they will germinate is not so great, since there are not enough nutrients for this.

The Angiosperms department unites plants that produce a flower and, accordingly, a fruit. Inside this, the seeds are reliably protected from any adverse environmental influences, warmed and provided with the necessary supply of nutrients.

Advantages

Angiosperms are a department of higher plants that have undoubted advantages. In addition to protecting the seed and creating favorable conditions For the development of the embryo, they also include the adaptation of seeds to dissemination. For example, maple fruits have special blades, thanks to which they are easily carried by the wind. And the poppy capsule itself cracks when ripe, spreading the seeds. Delicious fruits fruit trees are spread by animals that eat them and excrete undigested food residues at some distance. Gymnosperms do not have fruits. Their seeds are found in cones, which are not fruits at all. These are modified shoots that serve as a place for the formation and development of seeds. They have neither the supply of substances necessary for the development of the embryo, nor the devices for the dissemination of seeds and the settlement of plants.

Classification Features

The Angiosperms department is divided into two classes. The main feature of this division is the number of cotyledons in the seed embryo. The families of the Angiosperm department - Mono- and Dicotyledonous - have other characteristic features.

Division Angiosperms: general characteristics of Monocots

The Angiosperms department, class Monocots, includes more than 600 thousand species. The life forms in which it is represented are mainly grasses. In addition to one cotyledon in the seed embryo, representatives of this class are characterized by the presence simple leaves with parallel, and less often - with arc or pinnate type of venation. The cambium is the side of the stem and is absent in monocots. For this reason, they do not form powerful trunks. The monocot class includes several smaller systematic units - families.

Family Cereals

A characteristic feature of all cereal plants is the presence of a hollow stem. It's called a straw. Such a stem is formed due to the fact that the educational tissue is located in the nodes. Representatives of the family are wheat, rye, barley, corn, wheatgrass and other plants. One more characteristic feature cereal is an unusual flower in which the corolla is transformed into scales. The number of stamens varies from three to six, sometimes there are more. Such unusual flowers collected in inflorescences - a panicle or a complex spike. The ovary is formed by two carpels. The sessile leaves of cereals, without petioles, consist of three parts: the sheath, the ligule and the plate itself.

All cereals are very valuable food crops. Most of them are used to make cereals, flour, and baked goods. different varieties bread One of the representatives of cereal plants is sugar cane.

and Liliaceae

A characteristic feature of representatives of this family is the presence of an underground modification of the shoot - a bulb. It contains a supply of nutrients, thanks to which these plants remain viable throughout the entire unfavorable period. Chest and leeks are typical members of the family. But lily plants also form bulbs and sometimes rhizomes. Tulip, woodland, hyacinth, lily of the valley, hazel grouse... These plants are the first sign of spring. Before the onset of the dry period, they have time to grow and bloom. Then their aboveground part dies off, and the bulb underground remains viable throughout the entire period of existence of representatives of the Liliaceae family.

Class Dicotyledons: characteristic features

We continue to consider the Angiosperms department, the classes of which are well known to everyone. By the way, Dicotyledons are the most numerous of them. They have two cotyledons in the seed embryo, a taproot system, simple or compound leaves with pinnate, palmate or arcuate venation. In the stem of dicotyledons there is a cambium - a lateral educational tissue. It determines their growth in thickness. Therefore, such plants are characterized by the following life forms: herbs, shrubs and trees. The families that belong to this class are numerous. Therefore, we will consider only a few of them.

Family Rosaceae

That's as many as three thousand species fruit crops. Apple, pear, apricot, plum, quince, cherry, peach - these are just some of their representatives. They can be easily distinguished from others by their characteristic features: a five-membered flower with many stamens and a double perianth. Inflorescences - raceme or corymb. And the main types of fruits are drupes and apples. These crops are eaten and preserved by humans, because they have valuable taste qualities.

Family Legumes

This systematic unit has another name - Moths. These plants wear it due to the structure of the flower, the petals of which are of different shapes and externally resemble a butterfly with folded wings. And they owe their first name to the type of fruit - the bean. It is dry and opens with two flaps along the seam. Each of them contains seeds. The family includes medicinal, oilseed, fodder, food and ornamental plants. Their typical representatives are soybeans, peas, beans, clover, licorice, acacia, peanuts and other plants.

Family Solanaceae

The most famous crops representing the Solanaceae family, in addition to the plant of the same name, are potatoes, tomato, eggplant, sweet pepper and tobacco. Their flowers are also five-membered, but the sepals and petals are fused, and the fruit types are berry or capsule. Greatest economic importance Among them are vegetables and industrial crops, which include tobacco and shag. But the nightshade datura, henbane and belladonna are poisonous plants, capable of causing severe poisoning of the human body.

Brassica family

This systematic unit, so named because of its most typical representative, is also known as Cruciferous. The thing is that the flower has four petals located opposite each other. Outwardly, it resembles the shape of a cross. In addition to different types of cabbage, these include relis, turnip, radish, horseradish, mustard and rapeseed.

The importance of angiosperms in nature and human life

The Department of Flowering (Angiosperms) plants is, first of all, an integral part of almost all communities, a link in the food chain, the basis of green organic mass.

Among food crops, representatives of the families Cereals, Legumes, Rosaceae, and Cruciferae are of particular importance. Many plants are used to make medicines. These are licorice, marshmallow, valerian, tansy, St. John's wort, celandine. The fruits of flowering plants are rich in vitamins, especially C. These are strawberries, blueberries, viburnum, rose hips, garlic and onions.

No cultural landscape can be imagined without decorative flowering plants, among which the most common are roses, daffodils, dahlias, asters, petunias, daisies, lilies, tulips and others.

Many crops are honey-bearing. Their flowers have a pleasant aroma and sweet nectar, which attracts pollinated insects. Among such plants one can name different types of acacias, linden, and buckwheat.

But humans still have to fight with some flowering plants. These are malicious weeds: wheatgrass, quinoa, sow thistle, barnyard grass and others. Meet and poisonous species. Thus, if used incorrectly, celandine can cause severe convulsions, and dope can cause hallucinations, lack of consciousness control and delirium.

The characteristics of the Angiosperms department indicate their high organization, which allowed them to occupy a leading position in the plant world.