- Main article: Ground Tissue: Parenchyma
Parenchyma cells are thin-walled cells of the ground tissue that make up the bulk of most nonwoody structures, although sometimes their cell walls can be lignified. Parenchyma cells in between the epidermis and pericycle in a root or shoot constitute the cortex, and are used for storage of food. Parenchyma cells within the center of the root or shoot constitute the pith. Parenchyma cells in the ovary constitutes the nucellus and are brick-like in formation.