Vascular Tissue System
In the diagram below note the following: the procambium is also derived from the apical meristem. It initiates the vascular system with cells that differentiate inside into primary xylem, and outside into primary phloem. In plants with secondary growth, there also develops the vascular cambium which makes possible added layers of secondary xylem and phloem. The persistent growth of the vascular cambium results in an increase in stem diameter.
Return to tissue systems of the shoot page