Cross section in a petiole of Phaseolus – bean

This is a paraffin section stained with toluidine blue. The uniseriate epidermis (blue arrow) shows trichomes. A row of vascular bundles (numbers 1 to 6) is observed with xylem in the center and phloem outside. Two additive vascular bundles (number 7 and 8) are seen in the left part of the section. The ground tissue, parenchyma (par) is present in the center of the section and between the vascular bundles and the epidermis.
Scale: 500 µm