The common bottle cork is a product of:
As we discussed in
Cork cambium -
Cork cambium or extrastelar cambium or phellogen arises from the hypodermis or from the outer layer of cortex. Cork cambium divides periclinically(divides both outer and inner side). The outer side cells become dead and known as cork or phellem. The inner side cells are differentiated into parenolyma and contain chloroplasts. These cells are called secondary cortex or phelloderm.