Fig. 5.3-17. Transverse section of leaf of dracaena (Dracaena). Dracaena has long strap-shaped leaves that are strengthened by bundles of fibers, and it has both fibrovascular bundles (the single large bundle in the center) and fiber bundles (the three small bundles that consist of just fibers). Fibers in the fibrovascular bundle completely encircle the conducting tissues, creating a strong sheath, and almost certainly making it very difficult or impossible for the vascular tissues to either give off water pick up sugars from the surrounding leaf tissue.