Interfascicular cambium develops from the cells of
medullary rays
xylem parenchyma
endodermis
pericycle
A.
medullary rays
In dicot stems, the cells of cambium present between primary xylem and primary phloem is the intrafasicular cambium. The cells of medullary rays, adjoining these intrafascicular cambium become meristematic and form the interfascicular cambium.
In dicot roots the innermost layer of the cortex is called endodermis. Next to endodermis lies a few layers of thick-walled parenchymatous cells called as pericycle.