| ̷ ̷ ̷ ̷| ̷ ̷mə̇s noun
Etymology: New Latin, from end- + -dermis
: the innermost tissue of the cortex in the majority of roots and some stems consisting usually of a single layer of living cells with no intercellular spaces and with walls in part at least suberized or cutinized and often thickened in bands radially and transversely and supposedly functioning as a controlling element in the movement of water and other substances into and out of the stele — called also starch sheath ; compare casparian strip