What is phellogen? What is its function?
Phellogen, also known as cork cambium, is the meristematic plant tissue responsible for the formation of the periderm (the covering of the stem, shoots and roots). The inner side of the phellogen layer forms the phelloderm and its outer side forms the cork (suber). The suber secretes suberin, an impermeable substance that impregnates the tissue.
