Phellogen

phellogen

[′fel·ə·jən]

(botany)

The meristematic portion of the periderm, consisting of one layer of cells that initiate formation of the cork and secondary cortex tissue.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Phellogen

 

(also cork cambium), a secondary formative tissue of plants, consisting of vacuolated thin-walled parenchyma cells. Phellogen cells, divided by septa growing parallel to the surface of the organ, deposit cork cells on the exterior and phelloderm cells in the interior. Phellogen and its derivatives make up the periderm.

In trunks of willow and apple, phellogen is deposited in the epidermis, while in elder and ash it is deposited in the subepidermal layer. It is deposited in the primary cortex in currant and larch and in the central cylinder in grape. In the roots of conifers and dicotyledons it is deposited in cells of the pericycle located around the conducting tissues, which retain their capacity to divide. A heavy deposit of phellogen in the secondary phloem of woody plants and the development of internal periderms cause the formation of crust.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.