Plants of the division "Gymnosperms plants": characteristics, peculiarities of the structure, examples

Plants have a very important role in nature, as they are capable of photosynthesis. It is a process in which the plant from carbon dioxide, water and solar energy gets the nutritive substances and emit oxygen. Therefore, it is by plants on Earth may exist animals and you.

Classification of plants

The plant Kingdom is divided into ten departments:

• Brown algae.
• Green algae.
• Blue-green algae.
• Red vodorosli.
• Mahavidya.
• Paporotnikov.
• Homevideo.
• Lunovidnye.
• Pokrytosemennye.
• Golosemennye.

Among these plants, depending on the complexity of the structure can be divided into two groups:

• Low;
• Higher.

To include all the lower divisions of algae, since they lack tissue differentiation. The body has no organs. It ' s called a thallus.

Higher plants depending on the mode of reproduction can be divided into:

• Spore;
• Seed.

To include spore fern, mosses, mossy plants, homevideo.

Referred To the seminal divisions of gymnosperms and angiosperms.

About gymnosperms, we'll talk more in this article.

Classification of gymnosperms

The Next taxon that stands out in all the departments of the Kingdom "Plants" is a class. Gymnosperms are divided into four classes:

1. Gnatalie.
2. Ginkgolide.
3. Sagovnikovyh (Cycads).
4. Pine.

The representatives and the characteristics of each class we'll talk later. And now will be considered common features of all gymnosperms, their physiology and biology.

Gymnosperms: the structure of plants

This division applies to higher plants. This means that their body consists of organs, constructed of different tissue types.

Bodies of gymnosperms

Depending on the location of the bodies, they can be divided into underground and surface. Given their function and structure, we can distinguish the vegetative and generative organs.

Vegetative organs: structure and functions

This group of bodies is the underground root system and ground escape.

The Root system consists of many roots, among which you can select one main and many lateral roots. In addition, the plant can have extra roots.

The root of the following:

• Anchoring plants in the soil.
• The Absorption of water with dissolved micro - and macro-elements.
• Transport of water and dissolved minerals to terrestrial bodies.
• Sometimes the storage of nutrients.

The Escape is also the organ system. It consists of stem, leaves and buds.

Functions of the organs of escape.

• Stem: support and transport functions, providing a connection between roots and leaves.
• Leaves: photosynthesis, respiration, gas exchange, and temperature regulation.
• Kidney: formation of new shoots.

Gymnosperms and angiosperms have the same vegetative organs and generative organs that they have.

Generative organs of gymnosperms

Generative organs are those which ensure the reproduction of the organism. In angiosperm is the flower. But plants of the division "Gymnosperms plants" for the most part have generative organs such as buds. The brightest examples are spruce and pine cones.

The structure of the cones

It is a modified escape covered with scales. There are male and female cones, which are formed male and female sex cells (gametes), respectively.

Male and female pine cones as an example can be seen in the photo below.

There are representatives of the gymnosperms, in which both male and female plants are on the same plant. They are called monoecious. There are also dioecious gymnosperms. They have male and female cones are on different types. However, plants of the division "Gymnosperms plants" for the most part monoecious.

On the scales of female cones are located at two ovules, which produce the female gametes - egg cells.

On the scales of the male cones are pollen sacks. They formed pollen that contains sperm cells - the male gametes.

When we reviewed the structure of the gymnosperms and talk about their reproduction.

How the cones grow from pine

Gymnosperms Reproduction takes place through seeds. They, unlike the seeds of flowering plants, are not surrounded by fruit.

Reproduction of gymnosperms begins with the fact that plants in a certain period of kidneys are formed modified shoots - male and femalebumps. Then they formed pollen and ovule, respectively.

Pollination of the female cones takes place by the wind.

After fertilization of the ovules, which are located on the scales of female cones develop seeds. Of them and then form new representatives of the gymnosperms.

What tissues make up the organs?

Plants of the division "Gymnosperms plants", as all higher, consist of various tissues.

There are types of plant tissues:

• Cover. These tissues are protective. They are divided into the epidermis, the cork and crust. The epidermis covers all parts of the plant. It has stomata for gas exchange implementation. It can also be coated with additional protective layer of wax. Tube formed on the trunk, roots, branches and renal scales. Cork is integumentary tissue consisting of dead cells with lignified membranes. From it is the bark of gymnosperms.
• Mechanical. This fabric provides the strength of the stem. It is divided into collenchyma and sclerenchyma. The first is represented by living cells with thickened shells. The sclerenchyma consists of dead cells with lignified membranes. Mechanical fiber included in the conductive tissues contained in the stems of gymnosperms.
• Main fabric. It is the basis of all bodies. The most important kind of the main fabric - assimilation. It is the base of the leaves. The cells of this tissue are a large number of chloroplasts. Here is photosynthesis. Well as in the gymnosperms present a view of the main fabric as the stocking. It collects nutrients, resins, etc.
• Conductive fabric. Divided into xylem and phloem. The xylem is called wood, and phloem - the inner bark. They are in the trunk and branches of plants. Golosemennyh the xylem consists of vessels. It provides transport of water with dissolved substances from the root to the leaves. The phloem of gymnosperms is represented sieve tubes. The club is designed to transport substances from leaves to root.
• Educational fabric. From them are formed all the rest of the tissues of gymnosperms, which are then built all of the bodies. They are divided into apical, lateral and intercalated. Terminal located on the top of the shoot and the root tip. Lateral meristem are also called cambium. It is in the trunk of the tree between the wood and bast. Inserted meristem located at the base of the internodes. There are also wound meristem that arise on the site of the damage.

Here we have considered the structure of the gymnosperms. We now turn to their representatives.

Gymnosperms: examples

When we already know how the plants of this division, let's look at their variety. Next will be described the members of different classes, which are included in the Department "Gymnosperms".

Class "Gnatalie"

Plants of the division "Gymnosperms plants" class "Gnatalie" are divided into three families

1. Family "Valvitalia".
2. Family "Gnatalie".
3. Family "Hvojnikovye".

Let's consider the most prominent representatives of these three groups of plants.

So infinity is amazing. This is the only representative of the family valeviciene. This representative gymnosperm grows in the Namib desert and in other deserts of South-West Africa. The plant has a short but thick trunk. Its height is 0.5 m and the diameter is 1.2 m. since this species lives in the desert, he has a long main root, which is 3 m deep. The leaves that grow from the trunk of wallichii is a miracle. Unlike the leaves of all other plants on Earth, they will never fall off. They are constantly growing at the base, but occasionally die back at the ends. Constantly being updated so these leaves live the same as infinity itself (known specimens lived over 2 thousand years).

Gnatovich Family contains approximately 40 species. It's mostly shrubs, lianas, rarely trees. They grow in tropical forests of Asia, Oceania, Central Africa. Its kind Gnetova more like angiosperms. Examples of representatives of this family are melinjo, gnetum latifolia, gnetum ribbed, etc.

The Family hvojnikovye includes 67 species of plants. Life form shrubs and shrubs. They grow in Asia, the Mediterranean and South America. Members of this family have scaly leaves. Examples hvojnikovye can be called ephedra us, ephedra homely, cone-bearing ephedra, ephedra green, etc.

Class "Ginkgolide"

This group includes one family. The only representativethis family is Ginkgo biloba. It is a tall tree (up to 30 metres) with large fan-like leaves. This relict plant, which came on the Earth 125 million years ago! Extracts of Ginkgo are often used in medicine for the treatment of vascular diseases, including atherosclerosis.

Class "Sagovnikovyh"

It is also a gymnosperm. Examples of plants in this class: cycads of Rumpa, drooping cycads, cycad Thouars, etc. they Are all one family - "Sagovnikovyh".

They Grow in Asia, Indonesia, Australia, Oceania, and Madagascar.

These plants resemble palm trees. Their height is from 2 to 15 meters. The trunk is usually thick and short when compared with the thickness. So, cycads drooping its diameter is 100 cm, while the height is 300 cm

Class "Coniferous"

This is perhaps the most famous class of the Department of gymnosperms. It is also the most numerous.

This class consists of one order - "the Pine". At one time the Earth existed three orders of the class of conifers, however, their representatives have become extinct.

The above Mentioned order consists of seven semeistv:

1. Golovchitsy.
2. Toovie.
3. Sciadopityaceae.
4. Podkarpacie.
5. Araucariaceae.
6. Sosnovye.
7. Kiparisova.

Family golovchitsy consists of 20 representatives. This evergreen shrubs and trees. The needles are spirally arranged. From yew golovchitsy differ in that their cones much longer to Mature, and they have large seeds.

The yew Family includes about 30 species of shrubs and trees. All the plants of this family are dioecious. Examples of members of this family can be considered as the Pacific yew, Florida, canadian, and European yew trees.

The family sciadopityaceae includes evergreen trees that are often used as decorative.

Examples of representatives of the family podocarpaceae, you can call dacrydium, phyllocladus, podocarp etc. They grow in humid areas: in New Zealand and New Caledonia.

The Family Araucaria comprises about 40 species. The representatives of this family existed on the Earth during the Jurassic and Cretaceous periods. Examples can be considered South agathis, agathis dammar, the Brazilian Araucaria, the Chilean Araucaria, the noble and the Wollemi pine belongs to.

The pine Family includes such well-known trees like spruce, pine, cedar, larch, Hemlock, fir, etc. All the plants included in this family, grow in the Northern hemisphere in temperate climates. Gymnosperms plants of this family are often used by man in medicine and other industries due to their resins and essential oils.