Meristematic tissue :
Meristematic tissues may be defined as a group or collection of living cells which ar located specific locations and divide continuously to add new cells to the plant body. Characteristics of meristematic tissues :
The cells of meristematic tissues are similar in structure and have thin and elastic primary cell walls made up of cellulose.
These meristematic cells may be rounded, oval, polygonal or rectangular in shape.
They are compactly arranged without intercellular spaces between them.
Each cell contains dense or abundant cytoplasm and a large prominent nucleus.
The dense protoplasm of meristematic cell contains few small vacuoles or no vacuoles at all. Apical meristem :
This meristem is located at the growing apices of main and lateral shoots and roots. These cells are responsible for linear growth of an organ. Example root apical meristem and shoot apical meristem. Lateral meristem :
This meristem consists of initials which divide mainly in one plane and cause the organ to increase in diameter and girth. The lateral meristem usually occurs on the sides both in stem and root. Lateral meristem is of two types, i.e., in the form of cork cambium and in vascular bundles of dicots in the form of vascular cambium. The activity of this cambium results in the formation of secondary growth. Intercalary meristem :
This meristem is located in between the regions of permanent tissues. The intercalary meristem are usually persent at the base of node, base of internode or at the base of the leaf. They are responsible for growth of leaves and internodes.