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The outer layer of primary meristem or the primordial epidermis in embryonic plants. Also known as protoderm.
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 It might be outdated or ideologically biased.



in plants, the dense (without intercellular spaces) outer layer of cells of primary formative tissue (promeristem) in growing root tips.

Dermatogen cells usually divide such that the septa formed are perpendicular to the root surface—that is, anticlinal. (Only in the aerial roots of the orchids and arum families and in the thick underground roots of some amaryllis and lilies are they parallel to the surface of the organ, or periclinal, forming a multilayered covering—the so-called velamen.)

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