As the epidermis is at first replaced by the periderm, so in turn is this replaced by cork (the dead tissue).
When in this manner a continuous layer of cork arises, steadily increasing from the inside, it is termed “periderm.”
The development and configuration of the cork cells may change periodically during the formation of periderm.
periderm per·i·derm (pěr'ĭ-dûrm') or per·i·der·ma (pěr'ĭ-dûr'mə)
The outermost layer of the epidermis of an embryo or a fetus up to the sixth month of gestation. Also called epitrichium.
The outer, protective layers of tissue of woody roots and stems, consisting of the cork cambium and the tissues produced by it. See more at cork cambium.