Polyarch condition is a characteristic of monocot root in which numerous vascular bundles are present. Dicot root is diarch to hexarch i.e., 2-6 xylem and phloem patches are present. Pith in a dicot root, is either absent or is inconspicuous. In dicot root, phloem and xylem bundles are separated from each other by one or more layers of small thin walled cells called conjunctive parenchyma, which later on becomes meristematic to form vascular cambium.