This cross-section has a good view of a stem showing very clearly the cortex in relation to the epidermis and the vascular bundles and pith. The cortex is mainly thin-walled parenchyma cells with some chlorenchyma immediately subtending the epidermal tissue.

The pith is the cylinder of cells in the middle of the stem. These cells are generally large uniform shaped parenchyma cells about which the primary vascular bundles are loosely arranged. The picture below is another good example showing the arrangement of the primary tissues with the pith located to the interior, the interfasicular parenchyma (between the vascular bundles), cortex, and the epidermis. Note: The region of cortical parenchyma tissue between the vascular bundles called the interfascicular parenchyma will de-differentiate into a cambial group of cells upon initiation of secondary growth.