Sap is a fluid A fluid is a substance that continually deforms under an applied shear stress. All gases are fluids, but not all liquids are fluids. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids transported in xylem 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 , "wood", and indeed the best-known xylem tissue is wood, though it is found throughout the plant. Its basic function is to transport water but it also transports some cells (tracheids Tracheids are elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts. Tracheids are one of two types of tracheary elements, vessel elements being the other. All tracheary elements develop a thick lignified cell wall, and at maturity the protoplast has broken down and disappeared. The presence of or vessel elements) or phloem In vascular plants, phloem is the living tissue that carries organic nutrients , particularly sucrose, a sugar, to all parts of the plant where needed. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word φλόος (phloos) "bark". The phloem is concerned mainly with the transport of sieve tube elements In plant anatomy, sieve vascular tissue tube elements, also called sieve tube members, are a type of elongated parenchyma cells in phloem tissue. At the ends these cells are connected with other sieve elements, and together they constitute the sieve tube. The main function of the sieve tube is transport of carbohydrates in the plant . Unlike of a plant Plants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant species of plants, defined as seed plants, bryophytes, ferns and fern allies. As of 2004,. Fluid found in the vacuoles A vacuole is a membrane organelle which is present in all plant and fungal cells and some protist, an