HORTICULTURE

Detailed explanation-1: -Cell division by the cambium produces cells that become secondary xylem and phloem. As secondary phloem and xylem tissue accumulates, it both increases the girth of the stem and forms wood and bark.

Detailed explanation-2: -cambium, plural Cambiums, orCambia, in plants, layer of actively dividing cells between xylem (wood) and phloem (bast) tissues that is responsible for the secondary growth of stems and roots (secondary growth occurs after the first season and results in increase in thickness).

Detailed explanation-3: -So, the correct answer is ‘Cambium’.

Detailed explanation-4: -The cambium present between primary xylem and primary phloem is called the intrafascicular cambium (within vascular bundles).

Detailed explanation-5: -…a lateral meristem called the vascular cambium (Figure 8). The vascular cambium, which produces xylem and phloem cells, originates from procambium that has not completely differentiated during the formation of primary xylem and primary phloem.