Photographic reconstruction of the central nerve of the leaf observed with the objective of 40x. We can distinguish the upper epidermis and, below, the spongy and palisade parenchyma. In the microphotography appears a ramification of the main bundle, cut longitudinally. Over the conductive elements (xylem (yellow) and phloem) is located a zone of collenchyma, both towards the zone of the upper and lower epidermis (non-visible in this microphotography). There are numerous transverselly cut sclereids below the phloem