ABSTRACT
The primary apical meristems of the root and shoot produce the cells and tissue systems of the primary plant body (Cutter, 1978), such as the epidermis, cortex, and primary vascular tissues, and give rise to elongation growth. Secondary growth (synonymous with secondary thickening) is the province of the two laterally situated secondary meristems, the vascular cambium (herein simply referred to as the cambium) and the cork cambium, and results in increase in girth of the organ. Products of these two cambia together constitute the secondary plant body-secondary xylem and secondary phloem, and periderm, respectively.
