Light micrograph of a section through the stem of a sunflower plant Helianthus, showing the vascular bundles. The large white vessels, tinged with red and aligned like fingers constitue the xylem. The xylem transports water and minerals from the roots, through the stem to the leaves. Above the xylem is a layer of cambium, and above this, also stained red, are the cells of the phloem. The phloem forms the other part of the vascular bundle. It is a system for conducting the sugar manufactured in the leaves to the rest of the plant. Magnification: x40 at 35mm size.