Before we start studying meristematic tissue, understand something about plant tissues.
The word tissue was first pronounced and used by a French anatomist and pathologist, Marie Francois Xavier Bichat. That’s why Bichat is called father of Histology (study of tissues). Maric Bichat distinguished 21 types of elementary tissues from the organs of human body are composed. The branch of Biology in which tissues are studied is called Histology and this branch was established by an Italian scientist Marcello Malpighi. But the branch of Histology was firstly pronounced by Karl Fredrich Meyer in 1819.
Plant tissues are found in those plants whose synergetic 20 capacity of cell division is key to the survival are called meristematic tissue. These tissues are usually found in growing parts or organelles of the plants. They include the sepal, receptacle and stigma of the flower, apex of the root, cambium.
In the phases of regular and rapid cell division, the cell length and thickness of the tissues abruptly increases because the cells of these tissues are in the phase of cell division.
Meristematic tissues are very small and spherical in look. These tissues do not store foods in common. Meristematic tissues are rich in high metabolism. It has a single nucleus with a larger size.
Characteristics of Meristematic Tissues:-
A. Meristematic tissue has cell walls and has an identical structure.
B. The shapes of the cells in such tissues are spherical, elliptical or of having multi surfaces.
C. The cells of such tissues are very tightly interconnected and so there is no space between the cells inside the cells.
D. In the cells of such tissues, condensed cytoplasm, and larger nuclei are found.
E. The main function of meristematic tissue is to take part in regular and rapid cell division and to form new regular cells.
F. In the cells of such tissues, lesser number of vacuoles or negligible vacuoles are found.
Types of Meristematic Tissue
Mainly the meristematic tissue is of three types.
- Apical Meristem
- Lateral Meristem
- Intercalary Meristem
Such tissues are found at the apexes of the roots and stems of the plants and directly respond to the primary growth, especially the heights or lengths of the plants. In the orbits of the petals of the buds of the leaves, apical meristem tissues are present.
Functions of Apical Meristem
- The main function of apical meristem is to create cells.
- Another important function is the growth of the plants for their longevity and sustainability.
2. Lateral Meristem
Usually, such tissues are found in the apexes of dicotyledonous roots and stem in the parallel lateral axes of the plant organs. Through the cellular division of lateral meristem tissues, the girths of roots and stems abruptly increase.
Vascular Cambium and cork cambium are the examples of lateral meristem.
Functions of Lateral Meristem
- These are the secondary meristems for growth after apical meristem.
- Also, it increases the girth of the plant axis.
3. Intercalary Meristem
Such types of tissues are the residues of the apical meristems which become separated due to the appearance of the permanent tissues. Due to the activation of such tissues, the heights of the plants increase.
This type of tissue is especially useful for those plants whose apex part is generally eaten by vegetarian animals like the edible part of the grass. This meristem is present between permanent tissues. Its one of the inculcated tissues in the plant. It is located between leaves and internodes.
Functions of Intercalary Meristem
- It also participates in the growth of the plants.
- Grass is one of biggest examples of intercalary meristem.
- These are commonly found in conifers, angiosperms and ferns etc.