What is cork in plant anatomy?

In plant anatomy, cork refers to the outer bark of the cork oak tree ( Quercus suber ) native to the Mediterranean region. Cork consists of irregularly shaped, thin-walled, wax-coated cells. A cork cambium, a lateral meristem, develops in older phloem cells and forms cork cells. Cork cells push older secondary phloem cells outward, where they are crushed and shed. The walls of cork cells contain suberin, a fatty substance impermeable to gases and water. Cork protects trees from heat, fire, insect and fungal attacks, and water loss. The commercial cork is obtained by stripping the outer bark of the cork oak without harming the tree. The bark regenerates and can be harvested every 8–10 years.

Where can cork be found in a plant?

Cork, in the context of plant anatomy, refers to the outer bark of the cork oak tree (Quercus suber), native to the Mediterranean region. Cork is produced by the cork cambium, also known as phellogen, which is a lateral meristem found in woody plants. The cork cambium produces cork cells towards the outside, which then replace the epidermis as the protective tissue. The cork cambium forms cork cells, and the walls of these cells become lined with suberin, a substance that makes them impermeable to gases and water. The term "cork" refers to the outer derivatives of the cork cambium, while "bark" includes all tissues outside the vascular cambium. Cork protects the tree from heat, fire, insect and fungal attacks, and water loss.

What is the main function of cork in a plant?

Cork, derived from the cork cambium , protects the plant body, replacing the epidermis as woody plants grow and expand. Cork cells are nonliving at maturity, with inner walls lined with suberin, a fatty substance that is impermeable to gases and water. Bark, which includes all tissues outside the vascular cambium, minimizes water loss, deters insect and fungal attacks, and protects against fire damage. The pattern of cork development determines bark appearance, which can be scaly, continuous, or intermediate.

How is cork different from other plant tissues?

Cork, unlike other plant tissues, is the outer bark of the cork oak tree, composed of air-filled cells with thin walls coated in wax. These cells form a watertight, flexible compartment, providing insulation and liquid impermeability. Other plant tissues include: * Dermal tissue This is the epidermis, the outer protective layer of a plant. * Vascular tissue This includes xylem, which transports water and nutrients, and phloem, which transports food. * Ground tissue This includes the pith and cortex. Unlike the inner bark, cork is not vital for the tree’s survival and serves to protect it from heat and dry winds. The cork oak can be repeatedly stripped of its outer bark because its inner bark develops regenerative tissue. This tissue proliferates cork cells, allowing for the formation of new cork sheathing.

What cells make up the cork layer in plants?

The cork layer in plants, also known as phellem, is composed of nonliving cork cells. These cells are produced outwardly by the cork cambium , or phellogen, a secondary meristem found in the periderm of stems and roots. At maturity, the walls of cork cells contain suberin , a waxy substance highly impermeable to gases and water. Cork cells may also contain lignin. As the cork cambium produces more cork cells, these displace and crush the epidermal cells, which eventually die and slough off.

How does cork help protect plants from water loss and disease?

Cork protects plants from water loss and disease through its unique structure and composition. Cork cells are nonliving at maturity, and their walls are lined with suberin , a fatty substance highly impermeable to gases and water. This impermeability helps minimize water loss from stems. Additionally, cork acts as a resilient barrier against external invaders, preventing insect and fungal attacks. The cork cambium produces cork cells that displace and crush old phloem cells towards the stem's outer margins, forming the outer bark. Bark protects the living tissue from desiccation and environmental disturbances.

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Cork oak tree (Quercus suber) with thick, rough bark partially stripped, revealing smooth, reddish inner trunk and branches against a blue sky.

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plant anatomy

Also known as: phellem

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Top Questions

What is cork in plant anatomy?
In plant anatomy, cork refers to the outer bark of the cork oak tree (Quercus suber) native to the Mediterranean region. Cork consists of irregularly shaped, thin-walled, wax-coated cells.

A cork cambium, a lateral meristem, develops in older phloem cells and forms cork cells. Cork cells push older secondary phloem cells outward, where they are crushed and shed. The walls of cork cells contain suberin, a fatty substance impermeable to gases and water.

Cork protects trees from heat, fire, insect and fungal attacks, and water loss. The commercial cork is obtained by stripping the outer bark of the cork oak without harming the tree. The bark regenerates and can be harvested every 8–10 years.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Where can cork be found in a plant?
Cork, in the context of plant anatomy, refers to the outer bark of the cork oak tree (Quercus suber), native to the Mediterranean region. Cork is produced by the cork cambium, also known as phellogen, which is a lateral meristem found in woody plants. The cork cambium produces cork cells towards the outside, which then replace the epidermis as the protective tissue.

The cork cambium forms cork cells, and the walls of these cells become lined with suberin, a substance that makes them impermeable to gases and water. The term "cork" refers to the outer derivatives of the cork cambium, while "bark" includes all tissues outside the vascular cambium. Cork protects the tree from heat, fire, insect and fungal attacks, and water loss.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What is the main function of cork in a plant?
Cork, derived from the cork cambium, protects the plant body, replacing the epidermis as woody plants grow and expand. Cork cells are nonliving at maturity, with inner walls lined with suberin, a fatty substance that is impermeable to gases and water.

Bark, which includes all tissues outside the vascular cambium, minimizes water loss, deters insect and fungal attacks, and protects against fire damage. The pattern of cork development determines bark appearance, which can be scaly, continuous, or intermediate.
2 Britannica Sources
1. tree: Tree bark
2. angiosperm: Dermal tissue
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How is cork different from other plant tissues?
Cork, unlike other plant tissues, is the outer bark of the cork oak tree, composed of air-filled cells with thin walls coated in wax. These cells form a watertight, flexible compartment, providing insulation and liquid impermeability.

Other plant tissues include:
* Dermal tissue This is the epidermis, the outer protective layer of a plant.
* Vascular tissue This includes xylem, which transports water and nutrients, and phloem, which transports food.
* Ground tissue This includes the pith and cortex.

Unlike the inner bark, cork is not vital for the tree’s survival and serves to protect it from heat and dry winds. The cork oak can be repeatedly stripped of its outer bark because its inner bark develops regenerative tissue. This tissue proliferates cork cells, allowing for the formation of new cork sheathing.
2 Britannica Sources
1. cork
2. angiosperm: Dermal tissue
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What cells make up the cork layer in plants?
The cork layer in plants, also known as phellem, is composed of nonliving cork cells. These cells are produced outwardly by the cork cambium, or phellogen, a secondary meristem found in the periderm of stems and roots. At maturity, the walls of cork cells contain suberin, a waxy substance highly impermeable to gases and water. Cork cells may also contain lignin. As the cork cambium produces more cork cells, these displace and crush the epidermal cells, which eventually die and slough off.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does cork help protect plants from water loss and disease?
Cork protects plants from water loss and disease through its unique structure and composition. Cork cells are nonliving at maturity, and their walls are lined with suberin, a fatty substance highly impermeable to gases and water. This impermeability helps minimize water loss from stems.

Additionally, cork acts as a resilient barrier against external invaders, preventing insect and fungal attacks. The cork cambium produces cork cells that displace and crush old phloem cells towards the stem's outer margins, forming the outer bark. Bark protects the living tissue from desiccation and environmental disturbances.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

cork, the outer bark of an evergreen type of oak tree called the cork oak (species Quercus suber) that is native to the Mediterranean region. Cork consists of the irregularly shaped, thin-walled, wax-coated cells that make up the peeling bark of the birch and many other trees, but, in the restricted commercial sense of the word, only the bark of the cork oak merits the designation of cork. The cork oak grows abundantly in Portugal, Spain, parts of southern France and Italy, and North Africa. The tree is usually about 18 m (60 feet) tall, with a broad, round-topped head and glossy green, hollylike leaves.

Cork is obtained from the new outer sheath of bark formed by the inner bark after the original rough outer bark is removed. The outer sheath may then be stripped and will form again. Unlike the inner bark, the outer bark, or cork, is not vital to the tree’s survival and functions merely to protect it from the heat and dry winds of the Mediterranean summer. The repeated stripping of cork is possible because the inner bark of the cork oak develops an especially uniform and continuous regenerative tissue. After the outer bark has been peeled, this tissue proliferates sufficient cork cells to the outside so that, in a healthy tree, 2.5–5 cm (1–2 inches) of a uniform new cork sheathing forms in from 3 to 10 years. Stripping this regenerated layer yields commercial cork slabs.

The uniqueness of cork derives from its structure of air-filled cells, each of which consists of a watertight, flexible compartment. En masse these cells constitute a remarkably effective insulating medium that is also impervious to liquids. Because of its internal matrix of air pockets, cork is also among the lighter natural substances in weight, being only one-fifth as heavy as water. Specialized plastics and other artificial substances have supplanted cork in a number of its former uses, but cork has retained its traditional importance as a stopper for bottles of wine and other alcoholic beverages.

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