Meristematic tissue consists of actively dividing cells that help in the growth of plants. It is classified into three types based on its location. 

Apical meristem is found at the tips of roots and shoots and helps in increasing the length of the plant. 

Lateral meristem is present along the sides of stems and roots and helps in increasing the thickness or girth.

 Intercalary meristem is located at the base of leaves or internodes and helps in the regrowth of grass and other plants. These tissues are essential for the growth and development of plants.