The root, being the most important organ, performs a number of irreplaceable functions and is quite diverse in structural features. Without it, the life of plant organisms would be practically impossible. In our article, the fibrous root system will be examined in detail : in which plants it develops, what are its characteristic features and how it helps organisms to adapt to constantly changing environmental conditions.
What is root
The root is the underground organ of the plant. Obviously, in plants it is not in the singular. Indeed, all the roots of one organism differ in appearance and developmental features. There are three types of underground parts of plants: main, lateral and subordinate. Distinguish them is not difficult. The main root of a plant is always one. It stands out from the rest in size and length. Lateral roots grow on it. They are quite numerous. And if the roots grow directly from the shoot, then they are subordinate.
Root functions
Without a root, the plant will die, because its functions are really vital. First of all, this is the consolidation of organisms in the soil, providing mineral nutrition and an upward flow of water. If necessary, many plants form modifications of the root. For example, beets, carrots and radishes form root crops. This is the thickening of the main root. They accumulate water and the supply of necessary substances for experiencing adverse conditions.
Types of Root Systems
The root of one type is not enough for the plant. Indeed, the life of the whole organism depends on the functioning of this organ. Therefore, the plant forms root systems consisting of several types of underground organs. They are more effective. The main types of root systems are rod and fibrous. Their main difference lies in the structural features. For example, the fibrous root system is distinguished by a small penetration depth, and the core one, on the contrary, allows plants to receive water from considerable depths.
Core root system
The very name of this structure characterizes the features of its structure. She has a pronounced main root. This rod root system differs from fibrous. Due to this, plants with this structure are able to get water from a depth of several tens of meters. The lateral ones depart from the main root, which increases the suction surface.
The structure of the fibrous root system
The fibrous root system consists only of the roots of one type - adnexal. They grow directly from the aboveground part of the plant, so they form a bunch. Usually they are all the same length. Moreover, the main root at the beginning of development still grows. However, later it dies. As a result, only those roots that grow from the shoot itself remain. Such a bunch in most cases is quite powerful. Try to tear out a wheat plant with your hands from moist soil - and you will see that for this it is necessary to exert considerable force. Sometimes lateral roots can also develop on the subordinate roots, which further increases the diameter occupied by this system.
Which plants have a fibrous root system?
In the process of evolution, this structure first appears in representatives of higher spore plants - ferns, plunds and horsetails. Since in most of them the body is represented by an underground modification of the shoot, namely the rhizome, adnexal roots grow from it. This is a big step forward in the phylogenesis of plant organisms, since algae and other spore representatives had only rhizoids. These formations had no tissues and performed only the function of attachment to the substrate.
All plants that belong to the class Monocotyledonous have a fibrous root system . Along with the lack of cambium, arc or parallel venation and other signs, this is their systematic feature. This class is represented by several families. For example, in Liliaceae and Onions, a characteristic modification of the shoot is formed. This is a thickened underground stem, which stores water and all the necessary minerals. It is called an onion. Bunches of subordinate roots grow from it. Rice, wheat, corn, rye, barley are members of the Cereal family. They also have a fibrous root system. Examples of this structure are also dahlia, asparagus, sweet potato, chistyak. Their subordinate roots are significantly thickened and acquire a tuberous form. They also accumulate nutrients. Such modifications are called root tubers. Supporting, breathing, suction cups and trailers also grow from the shoot. Therefore, they can also be considered a modification of the fibrous root system. For example, lianas with the help of trailing roots can grow even on a vertical surface. And orchids absorb moisture directly from the air. This is carried out by the adnexal respiratory roots. A special modification is formed in corn. These are supporting roots. They surround the lower part of the stem and support a powerful shoot with heavy cob fruits.
Advantages and disadvantages of the fibrous root system
The fibrous root system has plants that do not have to extract moisture from a significant depth. This significantly distinguishes it from another similar structure - the core. It has a well-developed main root, capable of penetrating tens of meters deep into the soil. This characteristic for all plants of the class Dicotyledonous. But the fibrous root system has advantages. For example, it is able to occupy a significant area, which increases the suction surface. In wheat, the fibrous root system in diameter occupies up to 126 cm with a length of up to 120. The degree of development of this structure depends entirely on environmental conditions. In loose soil in maize, subordinate roots can grow in a radius of 2 m, in an apple tree up to 15 or more. Moreover, the penetration depth is quite significant. In some weeds, it reaches 6 m. Therefore, it is so difficult to get rid of them. If the soil is dense, and the oxygen content in it is insufficient, then almost all the subordinate roots are located in its surface layer.
So, the fibrous root system has a number of characteristic features. It is characteristic of monocotyledonous plants: the Cereal, Onion, and Lily families. This structure consists of subordinate roots that grow from the shoot with a bunch, occupying a significant area.