korkkikambion

Korkkikambion, also known as the phellogen, is a secondary meristematic tissue in plants responsible for producing the cork cambium and the phellem. It is a layer of actively dividing cells found in the outer bark of woody stems and roots. The cork cambium originates from the cortex or the epidermis.

The primary function of the cork cambium is to replace the epidermis as the stem or root grows thicker. It divides periclinally, producing new cells outwards that differentiate into phellem, commonly known as cork. These cork cells are dead at maturity and are filled with suberin, a waxy substance that makes them impermeable to water and gases. This waterproof layer provides protection against mechanical injury, dehydration, and pathogen invasion.

Inwardly, the cork cambium can produce a few layers of parenchyma cells, which together with the cork cambium and the phellem constitute the periderm. The periderm serves as a protective outer layer, replacing the epidermis that may be shed as the plant increases in girth. The rate of production of cork cells by the cork cambium varies with species and environmental conditions. In some plants, the periderm is formed early in development, while in others, it forms later. The formation of cork cambium is a key feature of secondary growth in dicotyledonous plants and gymnosperms.