Angiosperms are a department of the plant world. General Characteristics and Significance

It is simply impossible to list all angiosperms. Yes, and to name species that are of the most importance in nature and human life, will be quite difficult. After all, these plants have long been of great practical importance, and their representatives are known as food, technical, decorative and forage crops. What signs does the Department of Angiosperms have? The general characteristics and significance of these plants will be discussed in our article. So, let's get started.

Biology: Department of 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 environmental conditions. Department of Angiosperms, according to the systematics, for this period has more than two hundred and fifty thousand thousand species. While their predecessors - the Gymnosperm Department - are only eight hundred.

The main features of the Department of Angiosperms:

- the presence of a flower;

- formation of the fetus;

- development of the embryo within the seed rudiment;

- double fertilization;

- the presence of a seed surrounded by a pericarp.

Together, all these signs determine the advantages that the representatives of the Department of Angiosperms managed to spread across the planet, having mastered the conditions of different climatic zones and belts.

Golo- and Porosperms: similarities and differences

But back to basics. All seed plants are combined into two divisions: Golo- and Porosperms. The copies of the first systematic group are mainly represented by the class Conifers. This is a plant with a predominance of wood life form, with a rod root system. Foliage is represented by thin leaves - needles. Thanks to them and the presence of resin courses, which prevent the process of excessive evaporation, these plants remain evergreen throughout the seasons. But the main feature of this department is the absence of flowers, and hence of fruits. Seeds are located on the scales of cones openly, they are not protected. Therefore, the probability that they will germinate is not so great, since nutrients are not enough for this.

The Department of Angiosperms unites plants in which a flower is formed, and accordingly, the fruit. Inside this generative organ, the seeds are reliably protected from any adverse environmental effects, warmed and provided with the necessary supply of nutrients.

Benefits

Angiosperms are a department of higher plants, which have undoubted advantages. In addition to the protection of the seed and the creation of favorable conditions for the development of the embryo, the adaptation of seeds to spreading still has to be attributed to them. For example, maple fruits have special blades, thanks to which they are easily carried by the wind. A box of poppy itself is cracked when ripe, spreading seeds. Delicious fruits of fruit trees spread by animals that eat them, and secrete undigested food remnants at some distance. Gymnosperms have no fruits. Their seeds are in cones, which are not fruits at all. This is a modified shoots, serving as a place for the formation and development of the seed. They have neither the stock of substances necessary for the development of the embryo, nor the means for spreading seeds and the dispersal of plants.

Classification Features

The Department of Angiosperms is united into two classes. The main feature of this unit is the number of cotyledons in the seed germ. The families of the Department of Angiosperms - Odno-and Dicotyledons - also have other characteristic features.

Department of Angiosperms: a general characteristic of Monocotyledons

Department of Angiosperms, class Monocotyledon, includes more than 600 thousand species. The life forms that he represented are mostly herbs. In addition to a single cotyledon in the seed of a seed, representatives of this class are characterized by a lobed root system, the presence of simple leaves with parallel and, less often, arched or pinnate type of venation. Cambium is a lateral educational tissue of the stem, monocotyledonous plants are absent. For this reason, they do not form powerful trunks. The monocotyledon class includes several smaller systematic units - families.

Family Cereals

A characteristic feature of all cereal plants is the presence of a hollow stem. It is called a straw. This stalk is formed due to the fact that the educational tissue is located in the nodes. Representatives of the family are wheat, rye, barley, corn, wheat grass and other plants. Another characteristic feature of cereals is an unusual flower, whose corolla is transformed into scales. The number of stamens varies from three to six, sometimes more. Such unusual flowers are collected in inflorescences - a whisk or a complex ear. Ovary is formed by two carpels. Seated leaves of cereals without petioles, with parallel venation, consist of three parts: the vagina, the tongue and the plate itself.

All cereals are very valuable food crops. Most of them are used for making cereals, flour, baking different types of bread. One of the representatives of cereal plants is sugar cane.

Family Onions and Liliaceae

A characteristic feature of representatives of this family is the presence of an underground modification of the shoot - the bulb. It contains a supply of nutrients, thanks to which these plants remain viable throughout the unfavorable period. Chestnuts and leeks are typical representatives of the family. But the lily plants also form bulbs, sometimes rhizomes. Tulip, a lawn, hyacinth, lily of the valley, goose onion, hazel grouse .. These plants are the first sign of spring. Before the onset of the dry period, they manage to grow and flower. Then their overground part dies, and the bulb under the earth remains viable throughout the lifetime of representatives of the family Lily.

Class Dicotyledons: characteristic features

We continue to consider the Department of Angiosperms, whose classes are well known to all. By the way, dicots are the most numerous of them. They have two cotyledons in the seed embryo, a rod root system, simple or complex leaves with a feathery, palpate or arched venation. In the stalk of bipartite there is a cambium - a lateral educational tissue. It determines their growth in thickness. Therefore, such plants are characterized by such life forms: grasses, shrubs and trees. Families that belong to this class are numerous. Therefore, we will consider only some of them.

Family Rosaceae

This is an entire three thousand species of fruit crops. Apple tree, pear, apricot, plum, quince, cherry, peach - these are just some representatives of the Rosaceae family. They can be easily distinguished from others by characteristic features: a five-membered flower with a multitude of stamens and a double perianth. Inflorescence - a brush or a scutellum. And the main types of fruits are drupe and apple. These cultures man uses for food and preserves, because they have valuable taste qualities.

Family of Legumes

This systematic unit has one more name - butterflies. These plants carry it thanks to the structure of the flower, the petals of which are of different shapes and outwardly resemble a butterfly with folded wings. And the first name they owe to the type of fruit - a bean. It is dry and opens with two sashes on the seam. On each of them there are seeds. The family includes medicinal, oilseeds, fodder, food and ornamental plants. Their typical representatives are soybeans, peas, beans, clover, licorice, acacia, peanuts and other plants.

Family Nightshade

The most famous cultures representing the Nightshade family, except for the same plant 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 a box. The greatest economic importance among them are vegetables and industrial crops, which include tobacco and makhorka. But Solanaceous datura, bleached and belladonna are poisonous plants that can cause a strong poisoning of the human body.

Family Cabbage

This systematic unit, named similarly by the most typical representative, is also known as the Cruciferae. 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, they include release, turnip, radish, horseradish, mustard and rapeseed.

The importance of angiosperms in nature and human life

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

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

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

Many cultures are melliferous. Their flowers have a pleasant aroma and sweet nectar, which attracts pollinated insects. Among such plants can be called different types of acacia, linden, buckwheat.

But with some flowering people still have to fight. These are malicious weeds: wheat grass, quinoa, sow-stand, gooseberry, and others. There are also poisonous species. So, with improper application, the celandine can cause strong convulsions, and dope - hallucinations, uncontrolled consciousness and delirium.

Characteristics of the Department Angiosperms indicate their high organization, which allowed them to take a leading position in the flora system.