Cambium
Cambium is a thin region of actively dividing cells between the inner bark and the wood of a woody stem. During mango grafting, close alignment of living cambial regions helps the scion and rootstock form a functioning connection. Matching outer bark alone may not provide that contact when stems differ in thickness. Clean cuts, secure wrapping, and protection from movement support healing; pushing two cut surfaces together does not guarantee that their living tissues are correctly aligned.