
Cork cambium (: cambia or cambiums) is a
tissue found in many vascular plants as a part of the
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...
. It is one of the many layers of
bark, between the cork and primary
phloem
Phloem (, ) is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This transport process is ...
. The cork cambium is a lateral
meristem
In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic c ...
and is responsible for secondary growth that replaces the
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...
in
root
In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...
s and
stems. It is found in woody and many herbaceous
dicots,
gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s and some
monocot
Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but ...
s (monocots usually lack secondary growth). It is one of the plant's meristems – the series of tissues consisting of embryonic disk (incompletely differentiated) cells from which the plant grows. The function of cork cambium is to produce the cork, a tough protective material.
[Junikka, L. (1994) "Macroscopic bark terminology". ''IAWA Journal'' 15(1): 3–45][Trockenbrodt, M. (1990) "Survey and discussion of the terminology used in bark anatomy". ''IAWA Bulletin, New Series'' 11: 141–166]
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 vascular cambium is the main growth tissue in the stems and roots of many plants exhibiting secondary growth, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular ...
). 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
A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving soil fertility, fertility and health of the soil, reducing Weed control, weed growth, and enhancing the v ...
.
See also
* Complementary cells
* Frost crack
Frost crack or Southwest canker is a form of tree bark damage sometimes found on thin barked trees, visible as vertical fractures on the southerly facing surfaces of tree trunks. Frost crack is distinct from Sun scald (flora), sun scald and sun cra ...
* Sun scald (flora)
References
{{Biological tissue
Plant anatomy