Interfascicular and intrafascicular cambia together form a ring of cambium called cambial ring. It is formed due to the meristematic activity of cambium. The cambium which is found between the xylem and phloem is called fasicular or intrafasicular cambium and the newly formed cambium between the two vascular bundle is known as interfasicular cambium. Both type of cambium combine to form the cambial ring.

Phellogen is a meristematic tissue, while phelloderm is a permanent tissue. Phellogen (cork cambium) develops from the cortical cells, sometimes from pericycle cells. These cells actively divide and forms phellem on outerside and phelloderm (cortex cells)innerside on so phelloderm takes its origin from phellogen.

Phellem or cork is the outer most layer, followed by phellogen (cork cambium) which in turn is followed by phelloderm (secondary cortex).

Debark means the removal of bark, i.e., all tissue exterior to the vascular cambium, including secondary phloem. Bark refers to a number of tissue types, viz., periderm (phellogen, phellem and phelloderm) and secondary phloem.

Root is the organ which shows the features given in the question. Vascular bundles are present on separate radii thus called radial arrangement. Protoxylem is towards periphery of root thus making exarch condition.