Aspect of the vascular cylinder observed with the objective of 100x. On the right of the microphotography appears part of the endodermis, whose cell walls show a thick lignification in form of “U”. Underneath is located the pericycle, formed by a single layer of cells, surrounding the vascular bundles of phloem and xylem. The xylem is represented by the protoxylem (more externally located and showing vessels of reduced caliber), and the metaxylem (more internally located and showing large vessels). The phloem is placed next to the protoxylem, alternating with this one. Around the xylem vessels are observed cells of lignified walls, corresponding to the parenchyma of the xylem and the sclerenchyma (yellow)