Characteristics-

Cork is the outermost waterproof protective covering of stems and roots. It consists of dead cells when it gets matured, which are packed and lack intercellular spaces between them.

Cork contains a chemical suberin that makes the cork cells impervious to water and gases.

Cork is found as a tissue in vascular plants.

Formation- It is formed from the cork cambium of the plant. The outer protective tissue keep on changing as the plant grows. A strip of secondary meristem replaces the epidermis of the stem. Cells that are cut on the outer side by this secondary meristem are called cork.

Role of Cork- They prevent loss of water due to the presence of suberin in them, a chemical that makes cork cells impervious to water. Cork protects the plant from parasitic invasion. Cork is used in manufacturing insulation boards etc.