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Angiosperms: examples. Flowering plants

The group of angiosperms was formed more than 125 million years ago. And till now there are disputes about the concrete period (era) of their occurrence. Some call the Cretaceous period, others speak of earlier terms, others assure later ones.

There is no doubt that this category of plants has taken over the dominant position and has settled absolutely on all pieces of the globe, from tropical moist forests to the hot and icy deserts of Africa and the Arctic.

What are they, angiosperms? Examples, attributes and properties of a taxon, the classification will be considered below.

Angiosperms: general characteristic

Its name was given to representatives of this group for the ability to cover seeds with soft or hard tissues of the fetus. Indeed, in place of the flower, which is a visiting card of the taxon, the most diverse in shape and size, color and nutritional value of the structure are formed. They are called fruits.

The plant itself is a shoot that goes to the ground with a root system and has a flower, stem and leaves. The reproductive organ, characterized by a special structure and allowing to adapt to any habitats and conquer new territories for settlement, is the flower.

A more progressive structure that appeared in the course of the evolution of features and adaptations made it possible to displace representatives of gymnosperms, bryophytes and fern-like ones. Today, the flora of our planet is dominated by beautiful, bright, diverse in life forms angiosperms. Examples of them can be given for a very long time, because there are more than 13,000 births here. Briefly we can say this: all plants that have a flower are angiosperms.

General layout of the building

The main organs that each representative of this group have are those characteristic of all higher plants: root, stem, leaves. An additional structure that provided angiosperms with the possibility not to depend on water for the process of reproduction was the flower.

Parts of the flower: stipules, tsvetolozhe, pedicel, corolla of petals, ovary, pistil, stigma of pistil, stamens. All these structures are important as the reproductive organs, as well as those that later become a fruit that protects the seed until full maturation.

People appreciate plant flowers for their unusual beauty and tenderness, a pleasant fragrance. They use their medicinal properties, extracting useful extracts, grown with the aim of obtaining juicy and tasty fruits in the future.

For the plants themselves, the flower is a useful important organ that has saved them from water dependence during breeding, because now this is done with the help of double fertilization. Fruits provide protection and protect the seeds, as well as participate in their dispersion when eaten by animals, it is also a big plus that distinguishes the structure of angiosperms among other plants.

The different structure of flowers, the variety of their forms, allows to increase the methods of pollination, which also contributes to the wide spreading and dispersal of plants.

Features

Of course, the most important and reliable innovation for flowering plants was the formation of a flower. However, not only this, but also other signs of angiosperms favorably emphasize and confirm their mass predominance among the representatives of the flora. Such, for example, as:

  • The presence of a more perfect conductive system, including the sieve-like elements of the bast and the phloem tissue. This allows you to more quickly transport the necessary minerals and water, as well as promote organic substances to the desired parts of the plant for the purpose of their further storage.
  • Protection of seminal structures by the pericarp, often the thick flesh of the fetus.
  • A variety of methods of pollination (wind, insects, animals, birds, self-pollination, cross pollination and others).
  • Reproductive organs (gametophytes) are able to develop quickly and easily, are under reliable protection of the sporophyte plant itself.
  • Biochemical composition of tissues. Many representatives contain poisonous substances, alkaloids, flavonoids, phytoncides and so on, which prevent them from eating animals and prevent them from suppressing their growth to other plants.
  • The structure of angiosperms implies their existence in different life forms - trees, shrubs, shrubs, half-shrubs, grasses, lianas.

Such distinctive features make this group of plants very popular, hardy, adapted and widely dispersed. And also necessary and important for a person and his economic activities.

Classification

There are over 250 thousand species of angiosperms, united in 13 thousand genera from 350 families. Systematics is quite numerous in taxa and in representatives.

The classification is based primarily on classes of angiosperms, of which there are two:

  • Monocotyledonous plants;
  • Dicotyledons.

Each class is represented by a number of families, including different life forms and widespread in all territories.

Class Dicots

Includes angiosperms, examples of which almost everyone has at home in the form of potted flowers. These are violets, begonias, spatifillums, ficuses. From the garden-garden all Rosaceae and Nightshade, Cruciferae and butterflies, Complex flowers - rosehips, tomatoes, cucumbers, potatoes, cabbage, grapes, eggplant, buckwheat and many others. Among the tree forms there are also flowering plants, examples: oak, ash, maple, linden, birch and so on. Economically important representatives, sources of valuable raw materials: cotton, flax, jute, hevea, cinnamon, hemp, laurel and many others.

Total Dicotyledons have over 170 thousand species, which is approximately 75% of all flowering. Their classification includes 360 families, united in 60 orders from 7 subclasses.

Distinctive features of dicotyledonous

You can name a few basic.

  1. Presence in the seed of two cotyledons (halves). It is especially good to look at the example of the seed of leguminous crops. There are exceptions with one or three cotyledons.
  2. Root system type : core. It has almost all the given flowering plants. Examples on which it is easy to trace: pepper, hemp, nettle, begonias, spinach and so on. Exceptions are in wood forms.
  3. The flower is almost all four or five-membered. Rarely different.

Class Monocotyledons

There are about 80 thousand different representatives united in families. Numerous valuable angiosperms are examples of which can be cited as follows: all cereals, lily, Amaryllis, banana, sedge, most palms. And this is not the whole list, because each family includes a large number of specific species representatives.

Cereals are of great value in the human food industry. These include the most cultivated in the world crops: wheat, rice, barley, rye, corn and others.

Main features Monocotyledonous

We can name a few key:

  • The root system is friable, with rare exceptions;
  • Leaves lanceolate, elongated;
  • A three-membered flower, rarely four or two;
  • The cotyledon is in its embryo alone.

The classes of angiosperms and their numerous representatives form the diversity and beauty of the surrounding flora, which is so pleasant to admire and that gives us life. That's right, because oxygen produces plants, and without this gas, no animal can survive.

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