Astrovs are one of the largest and most common families of dicotyledonous. Their number includes more than 30 thousand species, which are combined in two thousand genera, which have become widespread in almost all climatic zones.
Description
The main part of the plants from the Astrov family is herbaceous perennial, less often annual. Sometimes shrubs and even trees can occur. So, scales reaches a height of up to 20 meters, and Brahilena grows up to 40 meters.
List of complex plants
Ageratum
Ambrosia
Aster
Marigold
Brahcoma
Garden Buzulnik
Gaylardia
Gatsaniya
Helenium
Heliopsis
Dahlia
Gerbera
Ginura
Chrysanthemum
Doronikum
Durnish
Zolotardik Canadian
Goldenfish is ordinary
Calendula
Coreopsis
Cosmea
Liatris
Daisy
Chamomile (matrix)
Osteosperm
Toping is common
Sunflower
Rock
Ratibida
Rudbeckia
Sanvitaly
Santolina
Stevia
Yarrow
Cineraria
City
Erigiron
Echinacea
Signs of astro plants
The main characterizing feature of the family is complexity is the presence of a kind of inflorescence in the form of a basket. As a rule, it includes many small flowers that are placed on a general bed. Such an inflorescence is surrounded by a wrapping of green leaflets. And in general, it looks like a single flower with many petals: bright examples sunflower, dandelion, chamomile.
The formula of compounded plants
Astro inflorescences do not differ in large sizes usually they are only a few centimeters in diameter. Of course, there are exceptions some species have inflorescences up to 15 cm, and the same sunflower can reach 60 cm.
The general formula of the inflorescence flower is very simple: CL (5) T (5) P1. We are talking about cups (4 pieces), petals (5), stamens (5) and pestle 1.
The inflorescence of complex plants
The main sign of astro plants is complex colors of flowers. T.e. In fact, such flowers are not at all flowers, but a basket of small flowers. They have a common bed the end of the pedicels with a concave surface and a common ward and a joint cup. The cup is made up of the rows of the straps, which form the basket. The flowers themselves are usually small, up to a pair of mm. The corolla of the inflorescence is concise, and in many plants of the family, it varies in shape.
Usually there are several types of them:
In some plants, the heads are only tubular flowers (cornflowers), in others only reed (dandelion), and others combine both types (sunflower).
The fruits of Astro plants
The fruits of astose plants are formed in the form of a seed this is a singleseeded nut that has a one nest and unexpressed with a characteristic leathery or even wooden shell.
At the same time, the base of the corolla is surrounded by peculiar bristles, which are formed in the crest that forms the semblance of a parachute. It is they who allow seedlings to fly in the wind.
In other species, for the same purpose, several spikes with teeth bent back (series) are located at the end of the fetus. These spikes use a seed to fix on wool or clothes to spread at considerable distances. And only a limited number of plants of the family is not equipped with special devices, with which the fruits spread.
Pollination of compounded plants
The pollination system of plants is not complicated: as a rule, insects cope with this. Everything is simple here: anthers tend to crack longing for longitudinal stripes, thanks to which a pollen tube opens. At this stage, the column is still hidden in a whisk and reaches only the base of the anthers. A little later, it begins to lengthen at a quick pace and then its upper end, or special hairs, work as a kind of ramrod, cleaning the inner surface of the tube. This process contributes to the release of pollen to the outside.
Thanks to this process, pollen sticks to insects and their legs, so that it would be transferred to other flowers.
Some types of astride (cornflowering, thistle) are also characterized by increased irritability of stamens, which significantly facilitates the process of pollen spread. So, insects, penetrating to the nectar, which gathers on the basis of the tube, irritate the threads of stamens with their proboscis, they are reduced, and this allows the pollen tube to pour into the end of the column. And so pollen is taken out.
The system is complex and at the same time simple only a few types of astro are pollinated by wind.
