cross section: Mature Ranunculus root common name: Buttercup magnification: 400x

<a href="http://blogs.berkshirecc.edu/bccoer" rel="noreferrer nofollow">Berkshire Community College Bioscience Image Library</a>

The cortex is well-developed and divided into two zones; a narrow outer layer of closely packed smaller parenchyma cells (exodermis) and a wide inner layer of larger open aerenchyma cells

The inmost area of the cortex is bounded by an endodermis or starch sheath with larger barrel shaped cells and thickened walls that mark the red staining casparian strip. Within the endodermis occasional small passage cells serve to transport of water into the stele or vascular bundle.

The stele is bound on its outmost edge by is a pericycle of single layered thin walled parenchyma cells.

The closed vascular bundles are arranged radially with arms of exarch xylem interspaced with patches of phloem and parenchymous conjunctive tissue. These tissues may become sclerenchymous in older roots