Cork cambium

Synonyms for cork cambium are bark cambium, peri-cambium and phellogen. Phellogen is defined as the meristematic cell layer responsible for the development of the periderm. Cells that grow inwards from there are termed phelloderm, and cells that develop outwards are termed phellem or cork (note similarity with vascular cambium). The periderm thus consists of three different layers:

• phelloderm – inside of cork cambium; composed of living parenchyma cells.
• phellogen (cork cambium) – meristem that gives rise to periderm.
• phellem (cork) – dead at maturity; air-filled, quite variable between different species, and is also highly dependent on age and growth conditions as can be observed from the different surfaces of bark, which may be smooth, fissured, tesselated, scaly, or flaking off.

Economic importance

Commercial cork is derived from the bark of the cork oak (Quercus suber). Cork has many uses including wine bottle stoppers, bulletin boards, coasters, hot pads to protect tables from hot pans, insulation, sealing for lids, flooring, gaskets for engines, fishing bobbers, handles for fishing rods and tennis rackets, etc. It is also a high strength-to-weight/cost ablative material for aerodynamic prototypes in wind tunnels, as well as satellite launch vehicle payload fairings, reentry surfaces, and compression joints in thrust-vectored solid rocket motor nozzles.

Many types of bark are used as mulch.