Among all known plants, various shrubs occupy a special place. This is due to their intermediate position between grasses and trees, as well as extremely important agricultural value. In this article, we will consider the features that allow us to determine that a shrub is a plant that has its own characteristic features. Also make sure of their diversity.
Possible plant varieties
Since the modern variety of plants is extremely large, their classification is necessary. Not only by strictly defined taxonomic units that help determine the location in the system of the organic world, but also by the appearance of the plant, that is, by its life form.
The most common system is the classification according to Serebryakov I.G., adopted in 1964. According to her, all plants are divided into the following groups:
- Woody plants. This category includes trees, shrubs, and shrubs.
- Semi-wood - shrubs and shrubs.
- Ground herbs.
- Water grasses.
The basis of such a classification is the length of the skeletal axes of the plant and the duration of its entire life.
According to Serebryakov, a shrub is a plant that has several wooden stems. In general, this is true and is a universally recognized feature of such plants. However, there are some subtleties of the structure of shrubs.
A shrub is a plant that has ...
To answer the question of what is called a shrub, we first give a few simple well-known examples of such plants. It:
- lilac;
- juniper;
- Rowan;
- bird cherry;
- sea buckthorn;
- dogrose and others.
Now that the visual representation of these plants is already clearly formed in the mind, a definition can be given from a scientific point of view.
A shrub is a plant that initially has one wooden trunk, but from a young age acquires several more of the same trunks, formed from sleeping buds. That is, there are quite a lot of trunks.
An adult shrub is a plant that has several equivalent wooden trunks, among which it is impossible to distinguish the main one. In this case, the basal rosette remains the only one for all stems. These plants can vary markedly in height.
So, for example, bird cherry is a fairly tall shrub that resembles in many respects a real tree. And dwarf willow is a very low flowering shrub, the height of which does not exceed 5 cm.
The main distinguishing features of shrubs
You can summarize all of the above and highlight several basic distinguishing features characteristic of shrubs:
- The presence of initially one trunk of a wooden type.
- The formation of many woody stems over time, which become completely equivalent for the whole plant.
- The presence of one basal rosette for all stems.
- Various sizes and fixtures for life.
- Shorter life cycle compared to trees.
- Inhabit almost all climatic zones of the Earth, from the subtropics to the tundra.
- All trunks are updated over time, which is due to the death of the old and the growth of new ones.
Thus, a shrub is a plant that has a number of distinguishing features that allow them to be isolated from grass and trees.
Shrub classification
Like all other natural forms of plants, shrubs have their own classification. According to her, they are of the following types:
- Those that have a completely lignified stem along the entire length. Among them, several options can be identified: loose, aeroxyl, lianoid, erect, creeping, real and pillow-shaped.
- With shortened trunks.
- Leafless shrubs storing water in the stems.
- Parasitic and semi-parasitic forms.
Let's take a closer look at each group and give examples to have an idea about these plants.
Shrubs with lignified elongated shoots
What types belong to this group, we have indicated above. Now briefly describe each of them and give examples.
- An erect shrub is a plant that has 1 (one) ligneous stem and several lateral branches growing vertically straight. These are transitional forms between shrubs and trees. Most species belong to this group. Examples: astragalus, fluffy birch, bird cherry, mountain ash and others.
- Real shrubs. These are those in which the aerial part of the shoot is less durable and thinner than the underground xylopodia. Examples: dogrose, barberry, bamboo, sea buckthorn, snowberry, lilac and others.
- Creeping shrubs are those in which the stems branch and creep along the ground, rooting in some places. Examples: mountain alder, juniper, willow.
- Lianoid bushes - like liana trees, they use other trees for growth. The difference is that the thickness of the trunk in shrubs is much less. Examples: honeysuckle, girl's grapes, lemongrass and others.
Obviously, this type includes the largest number of species of all shrubby forms known today.
Shrubbery Shrubs
A similar shrub is a plant that has one wooden stalk with very frequent leaf rosettes and highly shortened internodes. Therefore, from the side they look more like lush herbs.
Examples include the few species of heather, serpentine, Erica, rhododendron and some others. Habitats - Australia and Oceania.
Parasitic shrubs
This group includes several different species that have adapted to life at the expense of other plants. A typical example is mistletoe. This parasite settles on trees and sucks all vital juices out of them. At the same time, it itself has a fairly extensive deciduous crown and actively implements the process of photosynthesis.
A shrub parasite is attached to the branches of a tree with the help of special devices - a haustorium. Also, as an example, white Osiris and representatives of the family Rhinocerosaceae can be given.
An interesting representative of this family, known in Australia as a Christmas tree, is a richly flowered nuitsia. It got its name for beautiful bright orange and yellow flowers that bloom right before the New Year.
Obviously, a plant is called a parasitic shrub that has special adaptations for life due to other plant forms. Parasites of basal, stem, aboveground and underground are isolated.
Leafless shrubs
These include several families of cacti. Their thick fleshy stems serve to store water, and the leaves are practically reduced, being converted into needles to reduce the evaporating surface. That is why these shrubs received such a name. The place of growth is obvious - desert areas and typical deserts.
Examples are the species of the genus Opuntia. In height, these bushes reach four meters, the flowers are bright yellow or red. Also included are the species of the genus Euphorbia, which are used by people for a variety of purposes.