Slide 24: cross section of a eudicot stem showing the vascular tissue arranged in a continuous cylinder. The red sclerenchyma cells at the top of the slide are sclerenchyma fibers of the phloem. Under the fibers lie the phloem parenchyma and the conductive phloem, the sieve tube members (stained green). Next are several layers of cells that mark the area of the vascular cambium. The xylem cells (stained red) lie below the cambium. Note the large lumens identifying some of these cells as vessel elements. The parenchyma cells in the center of the stem constitute the pith, where excretory products can be deposited.