= Cells of cork are dead at maturity
= These cells are compactly arranged
= Cells do not possess intercellular spaces.
= Cells possess a chemical substances suberin in their walls
= They are several layers thick.
(b) As plants grow older, a strip of secondary meristem replaces the epidermis of the stem. Cells cut on the outer side by this meristem are called cork.
(c) They are protective in function for older stem/twigs/branches. They are impervious to gases and water.