Aspect of the cortex and the vascular cylinder (yellow) observed with the objective of 40x. In the cortex we can view the cells of the cortical parenchyma, of homogenous aspect. The limit between the cortex and the vascular cylinder is the endodermis, formed by a layer of cells showing lignified walls. Under the endodermis is placed the pericycle, constituted by a single layer of cells surrounding the vessels and the medullar parenchyma. We can also perceive the protoxylem (more externally located and showing vessels of smaller caliber) and the metaxylem (internally located and containing thicker vessels). Alternating with the elements of the protoxylem are placed the elements of the phloem. Around the vessels of the xylem appear cells showing red-stained lignified walls, corresponding to the parenchyma of the xylem and the sclerenchyma