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Asteraceae (or Asteraceae) are one of the most numerous families, which include many famous herbs and flowers. What is their feature, what characteristic features do they possess? Let's get to know the representatives of the group better.
- Description of family members
- Distinctive features of the structure of inflorescences and fruits
- Characteristics of other parts of plants
- The value of aster in economic activity and use in cooking
- Role in medicine
- Decorative representatives of Compositae
- Why do we need aster weeds
Description of family members
The Aster family, members of which belong to more than 100 genera, has about 25,000 species. Presented by annuals and perennials. Most of them are herbaceous (chamomile, wormwood, string). Sizes range from large to miniature. Herbs are most common in our latitudes, unlike other types.
Representatives of the Aster family (or Compositae) grow in all latitudes of the globe in very different climatic conditions. Most of them are noted in tropical and subtropical zones, as well as in temperate areas. They grow in meadows, mountainous and wooded areas. Less common in tropical forests with very high humidity and lowlands.
The second largest are semi-shrubs and shrubs with a height of 1-8 m. The rarest form is trees, covering only 2% of the total number. These are mainly exotic plants with a height of 30-40 m, living in Madagascar or other islands near the ocean. Some species form entire forests.
Among the Aster family, there are rosette trees. Their peculiarity is in a kind of crown located at the top and similar to a bunch. The height of such trees is 7 m. The place of life is New Zealand.
In warm countries, a small number of vines grows. This type is not typical for Compositae. In southern Africa, aquatic representatives are occasionally found. There are many succulents among the family that are capable of storing water and surviving drought. There are many of them in Madagascar and Ethiopia.
Compositae have become widespread throughout the earth due to their special chemical composition, which ensures stability and survival in extreme conditions. Some are toxic.
The most popular food representative is sunflower.
There are many decorative flowers in the family - asters, chrysanthemums, dahlias, gerberas. Chamomile and calendula are used medicinally. Such plants are the best known and closest to us.
Distinctive features of the structure of inflorescences and fruits
The family of Compositae got its name due to the complex structure of the flower. The basket inflorescence is the main distinguishing feature. The diameter depends on the species, for wormwood it is no more than a couple of millimeters. But the sunflower boasts 70 cm.
The inflorescence of Compositae has the appearance of a large flower. In fact, the appearance of a large bud is created due to the combination of many small flowers, the number can range from a few pieces to a thousand.
The flowers are located at the top of the pedicel, on an extended area with a flat, concave or slightly convex surface. The common calyx consists of several bracts, forming a basket.
In the Aster family, the flower formula is as follows:
H () L (5) T (5) P1 or L (5) T (5) P1, where H - calyx, L - petals, T - stamens, P - fruit.
The cups often have the appearance of hairs, membranes, scales, or are completely absent. The corolla consists of 5 fused petals. There are 5 stamens, which also grow together. The fruit is always one.
There are four types of flowers:
- Reed are observed in dandelion, chicory, lettuce, goat. It is characterized by an irregular bend.
- Tubular have a regular five-toothed bend. In many asters, it is this type that is inherent in artichoke, burdock, cornflower.
- The funnel-shaped ones do not have stamens and pistils (outer flowers of a cornflower).
- False-tongue are distinguished by three fused petals.
There are plants with mixed types of flowers. For example, there can be reed in a circle, and tubular in the middle. There are other combinations as well. Mixed flowers in asters, dahlias, sunflowers, chamomile, calendula. Pollination is often carried out by insects.
The family Compositae has a fruit - achene.
The sizes are usually small. The fruit always contains one seed inside, covered with a leathery or woody shell. The seeds are often surrounded by hairs that create a kind of parachute. Dandelion is a prime example. This feature helps to spread by the wind over long distances.
Some seeds are covered with thorns, which allows them to attach to animal fur and people's clothing. Aster fruits lack protein and a lot of oil.
Characteristics of other parts of plants
Other features are also characteristic of the Asteraceae family. Plants most often have alternate leaves, in rare cases - opposite ones. The shape and size may vary depending on the species.
Japanese butterbur, which grows naturally on the Kuril Islands, Sakhalin and Japan, is endowed with large leaf plates (up to 2 m). Small leaves (2-4 mm) are observed in the American baccharis. The most unusual foliage in rare lianas.
Leaves are often provided with pinnate venation. There are also specimens with parallel and arcuate veins.
The stem of Compositae is usually erect. It is often covered with hairs, like leaves.
The root system of Asteraceae is pivotal and well developed. The main root is thickened and resembles a tuber. Many representatives develop pulling roots. Some plants have a mushroom root.
Among the Asteraceae there are "compass plants" with unique abilities. At noon, their leaves turn sideways to the sun, the wider side turns to the east, the narrow one to the west. Plants of this type live in open areas with an abundance of light. Thus, they are protected from overheating and reduce moisture evaporation. Such specimens include wild lettuce and lobular sylphium.
Aster stems and leaves are sensitive not only to light, but also to moisture. For example, the sow thistle is used as a kind of barometer. If the basket of a plant does not open in sunny weather, then rain can be expected the next day. According to the behavior of the autumn gelenium, experts predict the weather conditions for the coming winter.
The value of aster in economic activity and use in cooking
The value of Astrov in economic activity is versatile. Plants of the family are used in medicine (chamomile, calendula), cooking (salad), for decorative purposes (gerberas, asters).
Sunflower is of great economic importance. Vegetable oil production is a whole industrial branch. One hectare of sown area produces one and a half tons of product. The plant got to our latitudes in the 18th century. The birthplace of the flower is North America.
Sunflower is a herbaceous plant that reaches 3-4 m in height. Despite the relatively large size, the flower is annual. The basket contains about 1000 flowers of the tubular type, in a circle there are flowers of the reed type, in which the seeds are not formed.
Sunflower prefers chernozem soils.
During cultivation, farmers carry out additional care: loosening the soil, removing weeds and using mineral fertilizers. To increase the harvest, beehives are placed near the fields. The flower is an excellent honey plant.
Thanks to the sunflower, the bee family manages to produce more than 5 kg of honey per day.
Sunflower oil is produced commercially. The product is consumed in its pure form and used for the production of margarine, mayonnaise, and bread. Sunflower oil is also involved in the production of linoleum, paints and varnishes, soaps and water-repellent fabrics.
An equally important role in the economy is played by the cake formed during the processing of seeds. Plant shoots are also used as animal feed, which grind and prepare silage. Sometimes the ground part of the flower is left in order to fertilize the soil.
The following Asteraceae plants are used in cooking:
- Lettuce. Young leaves, located on the root rosette, are eaten.
- Chicory. The plant is ground and used as an additive to coffee. People for whom caffeine is contraindicated brew chicory alone.
- Thorny lettuce. This compass plant is used for food.
- Jerusalem artichoke. Earthen pear tubers are used in cooking.
- Safflower. Safflower is used as a spice. A harmless food coloring is obtained from the petals.
- Dandelion. It turns out that jelly is made from dandelions. They are cut for making healthy salads.
Although not many plants are used for food, this does not diminish the importance of Asterians in human life.
Role in medicine
There are many plants among asters, which have a rich chemical composition and healing properties. Here are the most popular ones.
The flower is used not only for oil extraction. Shoots are used to create medicinal ointments and patches. Infusions are taken for liver diseases.
Chamomile inflorescences are collected and dried. This is done at the level of the medical industry. Chamomile is excellent at relieving inflammation, irritation and healing. It is used for all kinds of lotions, rinses, compresses and inhalations.
Alcohol tinctures are prepared from the flowers of the plant, dried inflorescences are brewed. Marigold-based products have an antiseptic and soothing effect.
Anticonvulsant and soothing tinctures are made with arnica extract. An effective anthelmintic agent is obtained from the flowers. Infusions have a healing, hemostatic and analgesic effect.
According to recent studies, artichoke has a choleretic, diuretic and antirheumatic effect. It is used for swelling, rheumatism, pathologies of the cardiovascular system, jaundice.
Outwardly, a nondescript plant with small flowers is of great medical importance. With his participation, they make medicines for the treatment of stomach ulcers.
Mother and stepmother
Decoctions and infusions are prepared from young leaves and inflorescences. Medicines are taken for bronchitis, pneumonia, bronchial asthma. They act as an expectorant, disinfectant and anti-inflammatory drug.
Echinacea is a popular herb that is known for its immune-enhancing properties. It is famous for its antiviral, bactericidal and anti-inflammatory effects. Echinacea-based preparations are used for eczema, wounds, sores. The plant has shown its effectiveness in sore throats, colds, flu. An important element of the flower is betaine, which can prevent the occurrence of strokes and heart attacks.
Decorative representatives of Compositae
Among the asters, there are many plants that are grown for decorative purposes. Many varieties are artificially bred by breeders. Flowers are supplied for sale in flower shops, grown in flower beds, gardens, parks. Some species are kept at home.
Luxurious perennial flowers that can please with long flowering. Their baskets are large and bright. Dahlias are grown in white, red, yellow, orange and other colors.
Annual and perennial asters are cultivated. The bud is made up of many small tubular flowers. The center of the flower is almost always yellow. The rest of the inflorescence is colored purple, red, white or pink.
Chrysanthemums are plants of extraordinary beauty. Greatness and sophistication compete with roses. Most of the chrysanthemum species are perennials. More than 5 thousand varieties with large buds have been bred. There are plants of a wide variety of colors. The shape and appearance of the flower differs depending on the variety. Large-flowered chrysanthemums look the most luxurious and rich.
Daisies are interesting little flowers that form turf trees. Plants sometimes form whole flowering carpets. Whole flower beds and lawns are planted with daisies. It blooms twice - in spring and late summer. Flowers bloom only on sunny days, baskets are closed before rain and at night. If in the middle of the day you notice closed daisies, know that soon it will start to drip from the sky.
Another wonderful ornamental plant is the gerbera. Outwardly, it resembles a large colored chamomile. A large bright flower looks very attractive. Gerbera is grown in flower beds and indoors.
Many flowers of the family are so popular and beautiful that breeders began to develop new varieties. Among the Asteraceae, plants such as marigolds, arnica, giatris, helenium, goldenrod, and cornflower are also grown for decorative purposes.
Why do we need aster weeds
There are many in the large family of Asteraceae and weeds. Here you can find yellow thistle, thistle, odorless chamomile, burdock. Some consider burdock to be a medicinal plant. The wild thistle and sow thistle form a branched root system extending 4 m deep. These weeds can interfere with the normal growth of crops.
Weeds also include a wildflower, a thistle, a blue cornflower, a dandelion, and a yarrow. Many of the weeds are food for herbivores.
In general, the role of Compositae weeds is very important for the biological world. A huge number of grasses are covered with seeds, which are later eaten by birds and animals. Plants line entire meadows and fields, maintaining balance in nature.
There are also specimens harmful to humans. For example, ragweed during flowering causes allergies in many people. In some countries, it is destroyed at the state level.
The Asteraceae family has given the world a huge variety of plants. Each of them occupies a specific niche. And although the economic usefulness of asteraceae is difficult to correlate with cereals or legumes, this huge group is very important for ecology and natural balance.
About the representatives of the Aster family in more detail, watch the video: