Scientist Haberland (1914) divided dividing tissue into three parts according to function.
(i) Protoderm: The dividing tissue that forms the skin of plants is called protoderm. Cells of this tissue form plant skin by atrial division (except bot, rubber). It forms the epiboema of the root.
(ii) Procambium: The dividing tissue that forms xylem, phloem and cambium of plants is called procambium. It is scattered in the stems of monocotyledonous plants and in ring form in the stems of dicotyledonous plants. It forms transport tissue or vascular bundles. In many plants it forms a cycle or pericycle.
(iii) Ground meristem: The dividing tissue that gives rise to cortex, pericycle, pith and medulla is called ground meristem.