In a dicot root, the outermost layer is epidermis. The
cortex consists of several layers of thin-walled
parenchyma cells with intercellular spaces the innermost
layer of cortex is called endodermis. The walls Of
endodermal cells have a deposition of water
impermeable waxy material suberin in the form Of
casparian strips.
Next layer to the endodermis is. thick-walled
parenchymatous cells called pericycle. The pith is small
and inconspicuous. There are usually two to four xylem
and phloem patches. Later, a cambium ring develops
between the xylem and phloem. All tissues on the
innerside of the endodermis such as pericycle, vascular
bundles and pith form the stele.