Page 84 - PG 101-Course notes مذكرة النظري 24-25 with spec

Medicinal plants (PG 101) Level 1 Clinical Pharmacy-PharmD

So, What is the Anatomy of the root?

In transverse section, the following regions are differentiated into:

1- Piliferous layer: One layered, cells are thin with no cuticle or stomata, their outer

walls have many root hairs.

2- Cortex: It consists of several layers of parenchyma cells, or some of them are

sclerenchymatous as in monocot.

◦ After the piliferous layer is ruptured, the cells of the outermost layer or few layers

of the cortex become suberized and replace the piliferous layer in the function

of protection. This hypodermal layer called exodermis.

◦ The innermost layer of the cortex develops into an endodermis, which is

characterized by the presence of the casparian strips.

◦ Casparian strips are deposits of suberin and lignin on the radial walls only (in

dicots), or on radial and inner tangential walls (in monocots).

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