middle lamella

This term is a specialized botanical expression used almost exclusively in plant anatomy and histology. It describes the outermost layer of the cell wall, functioning as a biological glue that ensures structural integrity by binding adjacent cells together.

Because it is composed primarily of pectins, the middle lamella is chemically distinct from the cellulose-rich primary and secondary walls. In a laboratory context, the degradation of this layer is what allows plant tissues to separate during certain developmental processes or through enzymatic digestion.