Cortex (botany)
1. Pith
2. Protoxylem
3. Xylem I
4. Phloem I
5. Sclerenchyma (bast fibre)
6. Cortex
7. Epidermis
In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells.