Ground tissues comprise all tissue except epidermis and vascular strands. It is the primary meristem formed apical meristem which gives rise to ground tissues of the plant body.
The ground tissue system of leaves is called mesophyll.
The ground system of monocot stem has hypodermis and ground parenchyma.
In dicot roots and stem the ground tissue system is differentiated into hypodermis, cortex, endodermis, pith and medullary rays.