Regeneration of Sclerenchyma in Wounded Dicotyledon Stems

When the sclerenchyma cylinder that surrounds the vascular cylinder in many dicotyledon stems is interrupted by cutting away one side of an internode, its continuity becomes restored in some species by the differentiation of sclereids within the wound callus. These sclereids, which may be scattered or arranged in clumps or in a continuous sheet, lie in a zone within the ‘cortical’ parenchyma between the regenerated vascular cylinder and the wound cork. The amount and especially the arrangement of regenerated sclerenchyma tends to reflect that of the original primary sclerenchyma cylinder in the unwounded stem, except that longitudinal continuity is poorly developed and all fibres are replaced by sclereids.