It is simply impossible to list all angiosperms. And to name the species that are most important in nature and human life will be quite difficult. After all, these plants have long gained their most important practical significance, and their representatives are known as food, industrial, decorative and forage crops. What are the signs of the Angiosperms department? The general characteristics and significance of these plants will be considered 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 Angiosperms department, according to systematics, for this period totals more than two hundred and fifty thousand thousand species. While their predecessors - the gymnosperms department - are only eight hundred.
The main features of the Angiosperms department are:
- the presence of a flower;
- fetal formation;
- development of the embryo within the seed germ;
- double fertilization;
- the presence of a seed surrounded by pericarp.
Together, all these signs determine the advantages due to which the representatives of the Angiosperms department were able to spread around the planet, having mastered the conditions of different climatic zones and zones.
Golo- and Angiosperms: similarities and differences
But back to the roots. All seed plants are combined in two departments: Golo - and Angiosperms. Instances of the first systematic group are mainly represented by the Conifers class. These are plants with a predominance of woody life form, with a rooted root system. 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 lack of flowers, and hence the fruits. Their seeds are located on the scales of the cones openly, they are not protected by anything. Therefore, the likelihood that they will sprout is not so great, because there are not enough nutrients for this.
The Angiosperms department unites plants in which a flower is formed, and, accordingly, a fruit. Inside this generative organ, the seeds are reliably protected from any adverse environmental influences, warmed up and provided with the necessary supply of nutrients.
Benefits
Angiosperms - the 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 distribution is still worth mentioning. For example, maple fruits have special blades, thanks to which they are easily carried by the wind. A box of poppies themselves crack when ripe, spreading the seeds. The tasty fruits of fruit trees are distributed by animals that eat them and secrete undigested food debris at a distance. Gymnosperms have no fruits. Their seeds are in cones, which are not at all fruits. These are modified shoots that serve as a place for the formation and development of the seed. They have neither a supply of substances necessary for the development of the embryo, nor devices for the distribution of seeds and the settlement of plants.
Classification Features
The Angiosperms department is combined in two classes. The main feature of this unit is the number of cotyledons in the seed germ. Families of the Angiosperms department - Monocotyledonous and Dicotyledonous - also have other characteristic features.
Angiosperms Division: General Description of Monocotyledons
The Angiosperms department, Monocotyledonous class, includes more than 600 thousand species. The life forms by which it is represented are mainly herbs. In addition to one cotyledon in the seed germ, representatives of this class are characterized by a fibrous root system, the presence of simple leaves with a parallel, and less often with an arc or cirrus venation. Cambium is a lateral educational tissue of the stem; in monocotyledonous plants, it is absent. For this reason, they do not form powerful trunks. The monocotyledon class includes several smaller systematic units - families.
Cereal Family
A characteristic feature of all cereal plants is the presence of a hollow stem. It is called a straw. Such a 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, 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 ear. The ovary is formed by two carpels. The sessile leaves of the cereal without petioles, with parallel venation, consist of three parts: the vagina, tongue and the plate itself.
All cereals are very valuable food crops. Most of them are used for the manufacture of cereals, flour, baking different varieties of bread. One of the representatives of cereal plants is sugarcane.
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 contains a supply of nutrients, thanks to which these plants remain viable during the entire unfavorable period. Garlic and leeks are typical members of the family. But lily plants also form bulbs, sometimes rhizomes. Tulip, woodland, hyacinth, lily of the valley, goose onions, hazel grouse .. These plants are the first sign of spring. Before the onset of the dry period, they manage to grow and bloom. Then their aboveground part dies away, and the bulb underground remains viable throughout the entire period of existence of the representatives of the Lileinidae family.
Class Dicotyledons: characteristic features
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 germ, the root root system, simple or complex leaves with cirrus, palmate or arc venation. The cambium is located in the stalk of dicotyledons - a lateral educational tissue. It determines their growth in thickness. Therefore, such plants are characterized by such life forms: grass, shrubs and trees. The families that belong to this class are numerous. Therefore, we will consider only some of them.
Rosaceae family
These are three thousand kinds of fruit crops. Apple tree, pear, apricot, plum, quince, cherry, peach - these are just some of the Rosaceae family. They can be easily distinguished from others by characteristic signs: a five-membered flower with many stamens and a double perianth. Inflorescences - a brush or scutellum. And the main types of fruits are drupes and apples. A person eats and preserves these cultures, because they have valuable taste qualities.
Bean family
This systematic unit has another name - Moth. These plants wear it due to the structure of the flower, the petals of which are of various shapes and 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 at the seam. On each of them are seeds. The family includes medicinal, oilseeds, fodder, food and ornamental plants. Their typical representatives are soy, peas, beans, clover, licorice, acacia, peanuts and other plants.
The nightshade family
The most famous cultures representing the Solanaceae family, besides the plants of the same name, are potatoes, tomato, eggplant, bell peppers and tobacco. Their flowers are also five-membered, but the sepals and petals are fused, and the types of fruits are a berry or box. Of the greatest economic importance among them are vegetables and industrial crops, which include tobacco and shag. But the nightshade dope, henbane and belladonna are poisonous plants that can cause severe poisoning of the human body.
Cabbage family
This systematic unit, named in a similar way thanks to the 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 value of angiosperms in nature and human life
The Department of Flowering (Angiosperms) plants is primarily an integral part of almost all communities, a link in the food chain, the basis of green organic matter.
Among food crops, representatives of the Cereal, Leguminous, Rosaceae, and Cruciferous families are of particular importance. Many plants are used to make medicines. This is 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, among which the most common are roses, daffodils, dahlias, asters, petunias, daisies, lilies, tulips and others.
Many crops are melliferous. Their flowers have a pleasant aroma and sweet nectar, which attracts pollinated insects. Among these 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 thistle, blackberry and others. There are also poisonous species. So, if used incorrectly, celandine can cause severe convulsions, and dope - hallucinations, uncontrolled consciousness and delirium.
The characteristics of the Angiosperms department indicate their high organization, which allowed them to occupy a leading position in the plant world system.