Tree Biology

Contents: - periderm - phellem - cork cambium - phelloderm - cortex - phloem- phloem rays - phloem - sieve tube element - companion cells - cambial zone (cambium) - bark - xylem - growth ring - vessels - tyloses - parenchyma - axial parenchyma - multiserrate ray parenchyma - uniserrate ray parenchyma - fibers - symplast - apoplast - growth ring/ray compartment - decay development

Click on any of the above terms to view its location in the tree cross section

Sieve tube elements move sugars from leaves toward roots. They are located just outside the cambial zone. They contain protoplasm. Moving sugars from one location to another in plants requires expenditure of energy.