Term:

Cortex
Definition:

A band of tissue in a stem or root between the bark and the vascular tissue. The cortex is made of of large, thin-walled parenchyma cells.
Notes:

The cortex is found in young stems. As the stems age, the cortex is crowded out by the growth of xylem, phloem, and bark. Cortical bundles are a feature of Lecythidaceae.
Related Terms:

Cortical bundle