Fruits are a protective shell for plant seeds. They may vary in color, shape, size and taste, but they all have a similar texture. Fruits are vegetables, fruits, berries, birch catkins, and nuts. It would seem that they are completely different, but they all have much in common.
Building
Fruits are a combination of substances that are designed to protect seeds from the external environment and increase the chances of their germination. They are also designed to spread the seeds as far as possible. This can happen with the help of wind, water, animals. The fruit consists of three parts: endocarp, mesocarp and exocarp. The first is the inner shell, it is located directly next to the seeds (several or one). Mesocarp is the middle shell, exocarp is the outer one. These three structures combine to form the pericarp, or pericarp. In most cases, the exocarp is represented by a skin (in fruit) or a shell (in a nut). Endocarp is most often that part of the fetus that is eaten by animals and humans. And the mesocarp can be seen, for example, in the form of a white shell betweenpulp and skin of an orange. However, there are exceptions to these rules. In apples, for example, the endocarp is presented in the form of transparent plates near the seeds, and the pulp is the mesocarp.
Fruits are different
They are divided into several groups, depending on their appearance and some structural features. Fruits are nuts, and cherries, and acorns - they all have a similar structure, but at the same time there are many differences.
Classification
The fruits of plants are divided into two large groups: dry and juicy. The second, unlike the first, have pulp. Dry are divided into multi-seeded (box-shaped) and single-seeded (nut-shaped), juicy - into drupe-shaped and berry-shaped. Each of these groups includes different types of fruits. There are quite a few of them. So, the box-shaped fruits of plants such as bean, pod, pod, pouch, leaflet, box. Nut-like are represented by caryopsis, lionfish, achene, nut and nut. Only juicy drupe belongs to drupes. Berry combine fruits such as berry, pumpkin, apple. Let's look at each of them in more detail.
Dry box-shaped
The first representatives of this group are beans. This fruit is found in all plants of the legume family. It consists of one carpel, has two seams along which it can be opened. This is a single-celled fruit. Plants with beans: beans, peas, lupins, lentils, mimosa, clover, wisteria.
The next type is pods and pods. These are the fruits of vegetables of the cruciferous family, to whichbelong to cabbage, mustard, lettuce, turnip, horseradish and others. It differs from the previous one in that it is two-nested, has two carpels. The boll is also a dry box-shaped fruit. It usually contains a very large number of small seeds. Such a fruit is formed by the following plants: poppy, henbane, carnation, dope. Its structure may have one or more carpels. The way the boxes are opened can also vary. In poppies, for example, the boxes have holes, in henbane - lids, in dope - sashes, in cloves - cloves.
Dry Nut Fruits
The first among them is, of course, the walnut.
Its main difference is its woody outer shell. Plants such as walnut, pterocaria, California, black, Manchurian nuts have such fruits. Hazel also forms similar fruits - these are nuts, they are smaller in size and have a softer shell. The achene also belongs to this group. This fruit has a leathery pericarp, with which the seeds do not grow together. It is formed by many composite plants, the most common and well-known of which is the sunflower.
Also, these are asters, daisies, marigolds, wormwood, dandelion, hairweed and many others. Caryopsis also belongs to this group of fruits. It is typical for plants of the cereal family, which combines crops such as rye, wheat, millet, bluegrass, bamboo, feather grass and others. This type of fruit is distinguished by a leathery pericarp, whichfuses with endocarp.
The next species is the lionfish. These are the fruits of the maple tree, as well as the ash tree. It has a pericarp with a leathery membranous pterygoid outgrowth that allows the seeds to be dispersed by the wind further away from the parent tree.
Juicy Berry
First of all, they include apples. They are characterized by membranous chambers in which the seeds are located, and the pulp is formed in the process of fusion of the tubule and the ovary of the flower. No, such fruits are formed not only by an apple tree, but also by all plants of the pink family: pear, mountain ash, hawthorn, quince and others. This group also includes berries that have a fleshy juicy pericarp. They are possessed by such plants: currants, blueberries, lingonberries, gooseberries, tomatoes, kiwi, eggplant, banana and others. Contrary to popular belief, cherries and raspberries are not berries, but drupes. Pseudo-berries include strawberries and strawberries, as well as wild rose - these are sets of fruits - multi-nuts.
The first two have real fruits (nuts) outside this structure (white dots), while the last one is inside. Birch catkins are also a set of nuts. Pumpkin is also a juicy berry. It has a juicy pulp, but a woody exocarp. Pumpkin, watermelon (the fact that it is a berry is also a delusion), melon, cucumber has such a fruit.
Drupes
This is also a subgroup of juicy fruits. Its only representative is a drupe. It is characterized by the fact that the seeds of fruits of this type are located inside the stone,located under the pericarp, having a hard outer shell and intended for additional protection. A drupe may contain either one or several bones. Examples of this type: plum, cherry, coconut, peach, apricot, viburnum. There are also complex fruits formed by several drupes. These are raspberries, blackberries.
What protects the pericarp?
Under these three shells is one or more seeds. Let's look at their structure. All flowering plants are divided into monocots and dicots - it depends on how many cotyledons their seeds have.
Seeds of monocotyledonous plants consist of one cotyledon, bud, stalk, root, from which, in fact, a new plant is formed, endosperm and seed coat, usually fused with the pericarp. Fruits with this type of seeds are, for example, pods and pods. It is also sometimes a box (at a tulip, lily), less often - a berry.
Seeds of dicot plants are distinguished by the presence of two cotyledons. Also, their structure differs from the previous ones in that their seed coat almost never fuses with the pericarp. These seeds can be found in fruit types such as drupe, apple, bean, achene, and others.
Methods of distributing fruits and seeds
They can be distributed with or without any "intermediary".
Thus, some plants throw their seeds out of opening fruits (most often beans). Also, the fruits can simply fall off under the influence of gravity from their weight. But more often theydispersed by wind, animals or humans, and water. To do this, the fruits often have additional adaptations, for example, dandelion pappus (fluffs growing from the pericarp, with the help of which dispersal with the wind).
