Some strains of S marcescens are capable of producing a pigment called prodigiosin, which ranges in color from dark red to pale pink, depending on the age of the colonies.
Vascular Tissue: the xylem and phloem in leaves are confined to vascular bundles or veins. Veins are surrounded by a layer of cells call the bundle sheath. The bundle sheath can be composed of parenchyma, colenchyma, or fibers.
In the circulatory system, veins (from the Latin vena) are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart.In contrast to veins, arteries carry blood away from the heart.Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow.ost veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart. Veins are less muscular than arteries and are often closer to the skin.