- Vascular Cambium
- Intercalary Meristem
Explanation: Lenticels are small pores that are found on the epidermis of stems, fruits, and petioles. They always remain open, and allow exchange of gases and water vapour.
As a secondary growth, a periderm layer is formed on the barks of trees, which is composed of three layers – phellem, phellogen and phelloderm. The phellogen layer often divides rapidly, leaving spaces between them which form the lenticels. The nearby cells are called companion cells.