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.
Plant veins are also sturdy enough to act as a support system and keep leaves open for photosynthesis -- the process through which plants make food. Plants have a vascular system throughout their roots and stems, but the system's veins are most visible in leaves.