Plant tissues: classification
General information
Like any other living organism, plants have a cellular structure, although they do not contain intercellular substance. The difference between their cells from others lies in a narrow specialization, which leads to a decrease in the ability to divide. In biology, the following plant tissues are distinguished: educational, basic, conductive, integumentary, mechanical. Of all the listed species, only cells of the educational and basic tissues can divide. Paradoxically, some plant tissues perform their functions only when they die. Now let's look at each separately.
The educational tissue of plants (meristem)
It divides by mitosis. Educational tissue has the following characteristics: it does not have a secondary cell wall; her cells are constantly dividing; it lacks colored plastids, so it is almost transparent. The meristem is primary (procambium, intercalary, apical) and secondary (pericycle, cambium, wound meristem, phellogen).
Underlying tissue (parenchyma) 
It performs storage, connecting, conductive, mechanical, protective, photosynthetic and secreting functions. Also, the main tissue is involved in the process of cell division. The parenchyma has a thick primary wall and lacks lignin in its secondary cell wall. In some cases, the main tissue is reborn into an educational one. Chlorenchyma, which synthesizes it, is responsible for the function of photosynthesis.
Mechanical cloth
This tissue is divided into sclerenchyma and collenchyma. It is they who give plants a certain strength. Sclerenchyma is the dead tissue of plants. It has thick secondary cell walls. By structure, this tissue is divided into fibers, which provide strength, and sclerides, which protect the plant from impact. Collenchyma is constantly in a state of turgor. That is why plants can move their individual parts in space. Most often, collenchyma is located under chlorenchyma (photosynthetic parenchyma). Collenchyma and sclerenchyma are dead tissues of plants.
Conductive fabric
It performs the function of transmitting information and water along the stems of the plant. The conductive tissue is divided into phloem, consisting of ray parenchyma, sieve cells, trunks, satellite cells, and xylem, consisting of living cells of the ray parenchyma, dead tracheid cells, vascular segments, libriform fibers, storage parenchyma. Xylem performs mechanical and conductive functions. The libriform fibers strengthen the xylem, and the radial parenchyma performs lateral transport. The phloem is partly composed of living cells that retain the cytoplasm but lack the nucleus. In this tissue of plants there are satellite cells that support the vital activity of phloem cells by pumping "through themselves" some chemicals. Phloem is popularly called bast.
They are located on the border of contact between the plant organism and the environment. These fabrics perform a protective function and also provide transportation of water and chemicals. They have thickened cell walls and a layer of wax, or cuticle, on the surface. Suction cells do not have a cuticle and have very thin walls. This tissue contains stomata, which perform the function of gas exchange. Integumentary tissues are divided into primary (rhizodermis, epidermis) and secondary (periderm). The latter consists of cork (fellema) and phellogen. The rhizodermis covers the roots, and the epidermis covers the rest of the plant organs. Phelloderma has the ability to store nutrients, since it resembles parenchyma in structure.
