Plant Tissue

Tissue may be defined as a group or layer of similarly specialized cells which together performs certain special functions. On the basis of the types of cells found in tissues, they are classified as animals and plants tissues.

Plant tissue

A group of plant cells performing essentially the same function and common to the similar structure is a plant tissue. On the basis of the stages of development, plant tissues are divided into two types:

1. Meristematic tissue
2. Permanent tissue

1. Meristematic tissue

The group of young cells which have the capacity of active cell division is called meristem. On the basis of origin, they are classified as primary and secondary meristems.

• Primary meristems: Those meristems, which are derived directly from the meristems of the embryo and responsible for primary growth and lie mainly on the apices of stems and roots, are called primary meristems. They are apical meristems (root apical and shoot apical meristems), intercalary meristems (only in monocots). They help increase the length of the plant.
• Secondary meristems: They are the meristems which are formed as new meristems in permanent cells by redifferentiation and are responsible for increasing the diameter of the plant organ. They are of two types vascular cambium and cork cambium collectively known as lateral cambium (lateral meristem). They help plant to increase its girth.

2. Permanent tissue

They are made up of cells that have lost the power of division and are differentiation to carry out various functions. The permanent tissues are of following types:

• Simple permanent tissue:These tissues are concerned with manufactured and storage of food and to provide mechanical support to plants.
• Complex permanent tissue:They are made up of different types of cells. The most important complex tissues are xylem and phloem.
• Special tissue:They are concerned with the secretion of materials like gums, oils, latex and other substances. They are further subdivided into two groups: lactiferous tissue and glandular tissue.