How are secondary vascular tissues formed in dicot roots?

(a) The primary dicot roots lack cambium,
(b) The vascular cambium appear later as a secondary meristem, which develops partially from conjunctive parenchyma and partially from pericycle. © The parenchyma cells lying beneath j the phloem bundles become meristematic to form cambium strips, (d) The cells of the pericycle just ! outside the protoxylem also become meristematic ! and joins with the cambium strips to form a wavy band of cambium ring, (e) This cambium ring form secondary xylem on the inner side and secondary phloem on the outer side, (f) The cambium is always more active towards the inner side during the formation of secondary vascular tissues