Translation of "abscission layer" into French

A layer of cells in a plant that differ from those above and below, and contain abundant starch and dense cytoplasm, which upon disorganization, begin the process of abscission, or the natural separation of the leaf from the rest of the plant.Philip Babcock Gove (editor), Webster's Third International Dictionary of the English Language, Unabridged (G. & C. Merriam Co., 1976 [1909], ISBN 0-87779-101-5), page 6