Vascular plants are a large class of plants which contain specialised tissues for the transport of water and minerals throughout the whole plant. These tissues are grouped together as the vascular bundle.
This illustration shows the structure of a vascular bundle from a monocotyledon root. At the centre (top) is the pith, which is surrounded by the xylem (white tubes) and phloem (green tubes). Xylem are responsible for the transportation of water around the plant, while phloem transport carbohydrates. The outer layer (bottom) is the cortex, which consists of supportive parenchyma cells.