Angiosperms - department of flora. General characteristics and meaning

Table of contents:

Angiosperms - department of flora. General characteristics and meaning
Angiosperms - department of flora. General characteristics and meaning
Anonim

It would be impossible to list all the 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 the most important practical significance, and their representatives are known as food, technical, ornamental and fodder crops. What are the characteristics of the Angiosperms department? The general characteristics and significance of these plants will be discussed in our article. So let's get started.

Biology: Angiosperms department

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 the adaptation of organisms to changing environmental conditions. The Department of Angiosperms, according to taxonomy, for this period has more than two hundred and fifty thousand species. While their predecessors - the Gymnosperms department - in totaleight hundred.

angiosperms department

Main features of the Angiosperm department:

- the presence of a flower;

- fetal formation;

- development of the embryo inside the germ;

- double fertilization;

- the presence of a seed surrounded by a pericarp.

Together, all these features determine the advantages due to which representatives of the Angiosperms department were able to spread around the planet, having mastered the conditions of different climatic zones and belts.

Holo- and Angiosperms: similarities and differences

But back to basics. All seed plants are combined into two divisions: Holo - and Angiosperms. The specimens of the first systematic group are mainly represented by the class Conifers. These are plants with a predominance of a woody life form, with a tap root system. The foliage is represented by thin leaves - needles. Thanks to them and the presence of resin passages that prevent the process of excessive evaporation, these plants remain evergreen throughout all seasons. But the main feature of this department is the absence of flowers, and therefore fruits. Their seeds are located on the scales of the cones openly, 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 combines plants that form a flower, and, accordingly, a fruit. Inside this generative organ, the seeds are reliably protected from any adverse environmental influences, warmed and provided withnecessary supply of nutrients.

department of flowering angiosperms

Benefits

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 distribution. For example, maple fruits have special blades, thanks to which they are easily carried by the wind. And the poppy box itself cracks when ripe, spreading the seeds. The tasty fruits of fruit trees are dispersed by the animals that eat them, and excrete undigested food debris over a distance. Gymnosperms do not have fruits. Their seeds are in cones, which are not fruits at all. These are modified shoots that serve as a place for the formation and development of the seed. They have neither a reserve of substances necessary for the development of the embryo, nor devices for dispersing seeds and settling plants.

Features of classification

Department Angiosperms are combined into two classes. The main feature of this subdivision is the number of cotyledons in the seed embryo. Families of the Angiosperm department - Mono- and Dicotyledonous - have other characteristic features.

Angiosperms department: general characteristics of Monocots

Department Angiosperms, class Monocots, includes more than 600 thousand species. The life forms it presents are mostly herbs. In addition to one cotyledon in the seed embryo, representatives of this class are characterized by a fibrous root system, the presence of simple leaveswith a parallel, and less often with an arcuate or pinnate type of venation. Cambium is the lateral educational tissue of the stem; it is absent in monocotyledonous plants. 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 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. Another characteristic feature of cereals is an unusual flower, in which the corolla is transformed into scales. The number of stamens varies from three to six, sometimes more. Such unusual flowers are collected in inflorescences - a panicle or a complex spike. The ovary is formed by two carpels. Sessile leaves of cereals without petioles, with parallel venation, consist of three parts: a sheath, a uvula 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.

department of angiosperms

Onion and Lily families

A characteristic feature of the representatives of this family is the presence of an underground modification of the shoot - the bulb. It is in it that the supply of nutrients is contained, thanks to which these plants remain viable throughout the entireunfavorable period. The parsley and leek are typical members of the family. But lily plants also form bulbs, sometimes rhizomes. Tulip, woodland, 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 have time to grow and bloom. Then their above-ground part dies off, and the bulb under the ground remains viable throughout the entire period of existence of representatives of the Liliaceae family.

department angiosperms general characteristics

Class Dicotyledonous: characteristics

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

Rosaceae family

This is as many as three thousand types of fruit crops. Apple, pear, apricot, plum, quince, cherry, peach - these are just some representatives of the Rosaceae family. They are easy to distinguish from others by their characteristic features: a five-membered flower with many stamens and a double perianth. Inflorescences - brush or shield. And the main types of fruits aredrupe and apple. People eat and preserve these crops, because they have valuable taste qualities.

biology department angiosperms

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 outwardly 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.

Solanaceae family

The most famous crops representing the Solanaceae family, in addition to the plant of the same name, are potatoes, tomato, eggplant, sweet peppers and tobacco. Their flowers are also five-membered, but the sepals and petals are fused, and the fruit types are berry or boll. Vegetables and industrial crops, which include tobacco and shag, are of the greatest economic importance among them. But nightshade dope, henbane and belladonna are poisonous plants that can cause severe poisoning of the human body.

department angiosperms general characteristics

Cabbage family

This systematic unit, named in this way due to the most typical representative, is also known as Cruciferae. It's all about the flowerhas four petals opposite each other. Outwardly, it resembles the shape of a cross. In addition to various types of cabbage, these include relis, turnip, radish, horseradish, mustard and rapeseed.

The importance of angiosperms in nature and human life

Department Flowering (Angiosperms) plants are primarily 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 Cereal, Legume, Rosaceae, Cruciferous families 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.

department angiosperms general characteristics

No cultural landscape can be imagined without ornamental 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 that attracts pollinated insects. Among such plants, one can name different types of acacias, linden, buckwheat.

But with some flowering people still have to fight. These are malicious weeds: wheatgrass, quinoa, sow thistle, barnyard and others. There are also poisonous species. So, if used incorrectly, celandine can cause severe convulsions, and dope can cause hallucinations, uncontrollability of consciousness and delirium.

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

Popular topic