1. Cork is outer protective tissue of older stems and roots.
2. Cells of cork become dead on maturity and contain resins , tannins and air
3. Cork is a compact tissue without intercellular spaces.
4. Cells of cork are rectangular in shape, arranged in several layers and impermeable to water due to deposition of suberin in their walls.
5. Cork is formed from secondary lateral meristem (phellogen or cork cambium)
6. (i) Functions. (i) Protection against pathogens. `" "` (ii) Prevent loss of water by evaporation.
(iii) Protection against mechanical injury to plant parts. `" "` (iv) Has lenticels for the exchange of gases.
(v) It is commercially used.