How the seeds spread through the wind. Methods of spreading fruits and seeds

Seeds are rare, but germinate directly in the plant. For example, after cutting a ripe pumpkin, we can observe already sprouted seeds in it. However, in the main they germinate not in places where they mature, but in a completely different place. What are they - ways of spreading fruits and seeds of plants? How does this happen and why? Let's find out!

What is the fetus

Before we consider in detail the ways of spreading fruits and seeds, these very concepts should be studied. After all, without elementary knowledge, it will be difficult for us to understand the whole process and mechanism of the "journey" of seeds and fruits around the world. So, let's begin. It's no secret that pear, plum, apple, strawberry, cherry are fruits of fruit plants and trees that contain seeds. It is believed that they develop from ovaries and other parts of plants, but not all botanists agree with this.

Some of them are sure that the real fruits can be called only those that are formed exclusively on ovaries, for example, cherries, plums, tomatoes, poppies, etc. Fruits that develop from other parts of flowers and plants are called false. For example, strawberries are generally formed by an overgrown floret. What kind of ovaries can you speak at all! As a result, scientists decided to consider the fruit as a result of the modification of the entire flower. At the same time, if at the beginning of their "life path" they still somehow can preserve some of the signs of a flower, then after maturation they completely lose or strongly modify them.

How are the fruits of plants

Outside, each fruit is surrounded by a so-called pericarp, which protects seeds from damage and drying out. In turn, the pericarp are divided into juicy and dry. For example, a juicy pericarp can be called the flesh of a ripe watermelon, melon or peach. Immature pericarp - astringent, bitter, sour, tasteless. During this period, it protects the fruit itself from untimely eating, and its still unripe seeds - from rapid damage.

Types of fruits

In order to understand how the seeds and fruits of these or those plants and trees spread, it is necessary to know that botanists refer to succulent fruits:

• Multi-seed (pumpkin, berry, apple, pomegranate);
• Single-seeded (peach, apricot, mango, cherry, bird cherry, prunes).

As follows from the name of the fetus, there is one stone in the one-seeded. They are also called drupines. However, here there is an exception: for example, the berry of the blackberry is a multicolored, but is a one-seeded fruit.

The methods of spreading fruits and seeds directly depend on their size, weight and shape. As already mentioned above, the fruits are juicy and dry. Dry, in turn, are divided into opening and not opening. For example, the pericarp of ripe beans, pods, and also the capsule of poppy are opened (burst) after their ripening. But, for example, the pericarp of the hazel is very hard and stiff. He himself for no reason in the world will not open. He has one single seed, which we perfectly know: a nut.

Another kind of fetus is the capsule. Usually it has from 3 to 5 nests with seeds. When these seeds mature, their "house" begins to burst. For example, the boxes of St. John's wort or tobacco give cracks along their partitions, after which they break up into separate parts. At the same time, only the walls crack in the "houses" of lilies, hyacinths, tulips and cotton, while in the poplar and willow the capsules generally crack at the seams. The most famous box is a pod, which during maturation with a crash splits into two leaves.

Is fruit considered a berry

Yes. This is a kind of fruit that has many seeds in its composition, but does not have seeds. If the berry is ripe, then it appears juicy and fleshy pericarp (grapes, strawberries, cranberries, cranberries, blueberries). That is why, from the point of view of botanists, cherry is not a berry, and tomatoes are! Here you can also include citrus fruits, which are also berries:

• Tangerines;
• Oranges;
• Lemons;
• Oranges;
• Grapefruits.

The fact is that the nests with seeds located inside the aforementioned fruits are filled with a fragrant exotic juice. Berries can be called the fruits of the family of pumpkin :

• Melons;
• Watermelons;
• Cucumbers.

A common man in the street is, of course, cutting the rumor, but professional botanists have long become accustomed to the idea that formally watermelon and cucumber are not only berries, but also relatives.

How the seed looks from the inside

The spreading of fruits and seeds (class 2, familiarization with the lessons of students' biology with some or other ways of "traveling" the seeds and fruits of various plants) is inconceivable without the participation of humans, animals and, of course, water and wind. But in order to understand how such a small seed can "travel" around the world, it is necessary to briefly get acquainted with its structure. So, any seed is covered with a peel. On smooth seeds, a hem is visible, which forms on the places where it separates from the seed stem.

If you look closely, then next to such a scar you can see a micro-polar hole, called in the scientific environment micropyle. Somewhere nearby is the tip of the root. It is with the germination of the seed that the very first appears outward. A dense peel protects the seed from various damages and at the same time lets moisture pass without interfering with the germination of the germ - the main part of all the seeds. It is formed only after fertilization of the egg and consists usually of a stem, root and kidney.

How are plant seeds propagated in nature

Well, here we come to the main thing. As already mentioned above, rarely sprouted seeds give life to new plants, since in the vast majority of cases they grow not where they ripened. Why is this happening? It's simple: they "travel" to new places through people, animals and Mother Nature herself! If the conditions for a new life turn out to be quite suitable, these seeds will begin to germinate, and if not, they will die.

1. An excellent way to spread them is cross pollination of plants, through which new species of flora can be formed. This is the minimum that gives life to new plants. Of course, the methods of spreading fruits and seeds of plants are not limited to pollination alone.
2. Unpleasant to the person on taste or at all poisonous fruits and seeds are rather attractive food for birds. In this case, seeds that have a hard shell are simply not able to digest in their stomachs. As a result, they, together with a bird's dung (guano), are transported to long distances from the place of their original "birth". But this role of birds in the spread of new plant life is not limited!
3. Many birds, arranging themselves supplies for the winter, drag the seeds and fruits of various plants in the nest. Some of them are simply lost during the flight of birds, falling into new places. For example, birds of a jay are constantly stocked with acorns, some of which are lost and germinate with time.
4. Another assistant in the germination of seeds and fruits is ants. These small, but useful in nature creatures carry to their nests the seeds of a variety of plants, especially rich in essential oils (cornflower, celandine, medinitsa, sour, violet). Like birds, ants lose the lion's share of the collected seeds en route. Incidentally, these little dodgers are basically available seeds of herbs.

How else do fruits and plant seeds "travel"?

They are mainly spread by the wind. Seeds in this case are scattered much better than the already formed fruits. But more about this later. As is known, in nature there are also so-called "living" fruits, which independently cling to the wool of animals, accidentally ran past, and also stick to the clothes of a person. For example, such are the fruits of burdock, string, cocklebur and burdock.

Here scientists-botanists especially note pisonia - a shrub or tree growing on the islands of the Pacific Ocean. The fruit of this unusual plant is enclosed in a special cup, seated with rows of various sticky hairs. They allow the fruits of pisonia to easily adhere to any animal or object. Often in nature, you can see reptiles and small birds, completely covered with such fruits. Unfortunately, in this case, animals can not fully move and die.

«Travel» by air

You know that fruits and seeds can spread with the help of wind, i.e. By air? For example, this occurs in the high-altitude steppes, in the savannahs and deserts, where strong winds constantly walk. In this case, the seeds simply scatter in different directions and over great distances. Especially good is the seeds, having a flat shape and small size (bell, hops, heather, broomrape, eucalyptus).

Winged seeds and fruits

It will be interesting to find out how the seeds spread with the help of wind, having so-called wings. They appeared in those plants that grow solely in open areas. These "wings" are specific hairs, which completely covered the seeds (for example, anemone). In poplars and willows, the seeds are generally provided with tufts consisting of the finest hairs.

In hazel, hornbeam, alder and birch, fruits are small nuts with wings. One wing has the fruits of tulip trees, ash trees and maples. Incidentally, that's why they spin when they fall. Spread by means of the wind seeds and fruits sedge bloated, puzyrnika, astragalov. It is curious that in these plants they travel in balloons, which are formed with the help of air sacs covering them.

Tumbleweed

Probably everyone at least once heard of such a bizarre plant. The scientific name to him is a swinging panicle. In the autumn it has the property of completely breaking away from its root. Friable and spherical bushes of this plant with ripe fruits are spread by the wind. Seeds in Kachima paniculate are hidden in capsules, the teeth of which have a curved shape. This allows the seeds to fall out only during a fairly strong gust of wind, which takes them to great distances.

"Journey" on the water

Not always the fruits and seeds of plants are spread by the wind. Seeds often "travel" along streams and rivers, are transported by sea currents and streams of rain. For example, a coconut can stay afloat in the open sea for years without losing its germination. Often, a whole stretch of land with palm trees and shrubs growing on it, as well as animals that live there, can break off from the shore. Such islands begin to swim with the flow, spreading the seeds of their trees thousands of kilometers away.