Slide 18: High power view of a longitudinal section of the Coleus apical meristem. The apical meristem is a dome-shaped mass of dividing cells at the tip of the shoot. The apical meristem will produce the three primary meristems: protoderm, procambium, and ground meristem. These three meristems in turn will produce new cells that will differentiate into the epidermis, primary vascular tissues, and ground tissues (pith and cortex). The leaves arise as leaf primordia along the flanks of the apical meristem and islands of meristematic cells left behind at the bases of the leaves by the apical meristem will become the bud primordia. Note the dark strands running into the leaf and, more faintly, down the edges of the stem. These are the procambial strands. Remember, all the tissues derived from the apical meristem are primary tissue, and result in elongation of the plant shoot.