In a dicot stem, the region between the endodermis and the vascular bundles is called the pericycle. 

• Endodermis:This is the innermost layer of the cortex, a single layer of cells that separates the cortex from the vascular bundles. 

• Pericycle:This is a layer of cells located just inside the endodermis and is the outermost part of the stele (vascular cylinder). 

• Vascular bundles:These are made up of xylem and phloem, which are arranged in a ring in dicot stems.