The Structure and Function of Plant Tissue Systems
Plant tissue systems include:

Dermal Tissue System

The dermal tissue system consists of the epidermis and the periderm. The epidermis is a single layer of closely packed cells. It both covers and protects the plant. It can be thought of as the plant's "skin." Depending on the part of the plant that it covers, the dermal tissue system can be specialized to a certain extent. For instance, the epidermis of a plant's leaves secretes a coating called the cuticle that helps the plant retain water.

Epidermis Cells Image copyright Dave Webb.

The periderm, also called bark, replaces the epidermis in plants that undergo secondary growth. The periderm consists of cork cells and protects the plant from pathogens, prevents excessive water loss and provides insulation for the plant.

Periderm formation is indicated by periclinal divisions in parenchyma cells. Image copyright Dave Webb.

Vascular Tissue System

Xylem and phloem throughout the plant make up the vascular tissue system. It allows water and other nutrients to be transported throughout the plant.

Xylem and Phloem Image copyright Dave Webb.

Ground Tissue System

The ground tissue system synthesizes organic compounds, supports the plant and provides storage for the plant. It is mostly made up of parenchyma cells but can also include some collenchyma and sclerenchyma cells as well.
Previously, we've looked at the structure and function of plant cells. We now turn our attention to plant
tissue systems.

Like other organisms, the cells in a plant are grouped together into various tissues. These tissues can be simple, consisting of a single cell type, or complex, consisting of more than one cell type.

Above and beyond tissues, plants also have a higher level of structure called tissue systems. There are three typical types.