Cambium

A series of formative cells lying outside of the wood proper and inside of the inner bark. The growth of new wood takes place in the cambium, which is very soft.

A fancied nutritive juice, formerly supposed to originate in the blood, to repair losses of the system, and to promote its increase.

a formative one-cell layer of tissue between xylem and phloem in most vascular plants that is responsible for secondary growth