: a layer of intercellular material that as seen by conventional staining and microscopic techniques lies between the apparent walls of adjacent plant cells
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Bot.
the layer of cementing material, composed of pectates and similar substances, between the walls of adjacent cells.
[1920-25]
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middle lamella,
Botany. the primary layer of a plant cell wall, composed chiefly of calcium pectate, on which, in older cells, secondary layers of cellulose are deposited.
Useful english dictionary. 2012.