In botany, the cortex in plants refers to a specific layer found in stems and roots.
Understanding the Cortex
The cortex is an outer layer of a stem or root in a vascular plant, sitting right beneath the epidermis (the outermost layer) and outside the vascular bundles (which contain the plant's transport tissues).
Cortex Composition and Structure
- Location: Found in both stems and roots.
- Position: Lies between the epidermis and the vascular bundles.
- Cells: Primarily composed of large, thin-walled parenchyma cells. These are part of the ground tissue system.
- Differentiation: Shows minimal to no structural differentiation, meaning the cells are quite uniform in their function and appearance.
Function of the Cortex
While structurally simple, the cortex plays several vital roles in plant physiology:
- Storage: The parenchyma cells often store starch and other substances.
- Support: Provides some structural support to the stem or root.
- Transport: Facilitates the movement of water and nutrients from the epidermis to the vascular tissue.
- Protection: May offer some protection to the inner vascular tissues.
A Visual Summary
| Layer | Position | Composition | Function |
|---|---|---|---|
| Epidermis | Outermost layer | Protective cells | Protection |
| Cortex | Below epidermis, outside vascular bundles | Large, thin-walled parenchyma cells (ground tissue) | Storage, support, transport, protection |
| Vascular Bundles | Innermost region | Xylem, phloem, cambium | Transport of water and nutrients, structural support, and cell production |
