cambium

[kam-bee-uhm]

noun

Botany.

plural

cambiums, cambia 

1. a layer of delicate meristematic tissue between the inner bark or phloem and the wood or xylem, which produces new phloem on the outside and new xylem on the inside in stems, roots, etc., originating all secondary growth in plants and forming the annual rings of wood.

cambium

/ ˈkæmbɪəm /

noun

1. botany a meristem that increases the girth of stems and roots by producing additional xylem and phloem See also cork cambium

cambium

plural

cambiums 

1. A cylindrical layer of tissue in the stems and roots of many seed-bearing plants, consisting of cells that divide rapidly to form new layers of tissue. Cambium is a kind of meristem and is most active in woody plants, where it lies between the bark and wood of the stem. It is usually missing from monocotyledons, such as the grasses.

2. ◆ The vascular cambium forms tissues that carry water and nutrients throughout the plant. On its outer surface, the vascular cambium forms new layers of phloem, and on its inner surface, new layers of xylem. The growth of these new tissues causes the diameter of the stem to increase.

3. ◆ The cork cambium creates cells that eventually become bark on the outside and cells that add to the cortex on the inside. In woody plants, the cork cambium is part of the periderm.

4. See also secondary growth

cambium

1. The layer of a tree where growth occurs, just under the bark.

Other Word Forms

• cambial adjective

Word History and Origins

Origin of cambium¹

1665–75; < Late Latin: an exchange, barter; akin to Latin cambiāre to exchange

Word History and Origins

Origin of cambium¹

C17: from Medieval Latin: exchange, from Late Latin cambiāre to exchange, barter

Example Sentences

“You have to scrape the bark or cut under the bark to try and find the living tissue that’s under the cambium and the inner bark,” he said.

From Los Angeles Times

Larvae hatched from eggs laid on an oak tree bore in to reach the cambium.

From Los Angeles Times

Tree wounds that penetrate bark damage the cambium layer, vascular tissue that is vital to movement of water and nutrients in a tree.

From Seattle Times

“But look, this is where a rodent has chewed through the bark to get at the moist cambium layer in each stem and get a little moisture.”

From Los Angeles Times

The trees don’t develop the classic fire-resistant characteristics — thick bark that protects the inner cambium and self pruning that sees them shed lower branches — until they reach about 500 years old.

From Los Angeles Times