Light micrograph of a transverse section through the root of an Iris, a monocotyledon, showing the central vascular tissues (green), the cortex (large-celled pink tissue) and an outer piliferous layer bearing numerous water-absorbing root hairs. The central vascular tissues are surrounded by a single layer of cells known as the endodermis (dark green ring). Within this is a star-shaped region of dark green xylem, with bays of pale green phloem lying between the arms of the star. The large white cells are water- conducting meta- xylem vessels, surrounding a small central region of parenchymatous pith. Magnification unknown.