In vascular plants, xylem is one of the two types of transport tissue, phloem being the other. The word "xylem" is derived from classical Greek ξυλον (xylon), "wood", and indeed the best known xylem tissue is wood, though it's found throughout the plant. Its basic function is to transport water. Physiology of xylem The xylem is responsible for the transport of water and mineral nutrients from the roots throughout the plant. Xylem sap consists mainly of water a… (More on Xylem)