$\bullet$ When the cells of medullary rays differentiated, they give rise to the new cambium called interfascicular cambium.

$\bullet$ Loose parenchyma cells rupturing the epidermis and forming a lens-shaped opening in bark are called complementary cells.

$\bullet$ Large colorless empty cells in the epidermis of grass leaves are called bulliform cells.

$\bullet$ In dicot leave, vascular bundles are surrounded by large thick walled cells called bundle sheath cells.