Question

how does cork form in a dicot tree

Answer 1

At the time period of development of secondary growth in the dicot stem and roots, the epidermal layer gets broken. The outer epidermal layer is replaced for providing protection to the stem and roots. The cork cambium develops from the cortical region. It is composed of thin-walled rectangular cells. The cells are cut off from both the sides. The cells on the outer side differentiates into cork or phellem. The cells on the inside develops into secondary cortex. The cork formed is impervious to water, but allow gaseous exchange through the lenticles.