There is a bundle sheath of much-flattened cells separating the fibro-vascular bundle from the ground tissue.
It is sharply separated from the ground tissue by a row of small cells, called the “bundle sheath.”
Just inside of the bundle sheath there is a row of similar fibres marking the outer limit of the phloem (ph.).
The larger vascular bundles consist of xylem and phloëm surrounded by a bundle sheath of a single layer of cells.
|bundle sheath |
A layer or region of compactly arranged cells surrounding a vascular bundle in a plant. The bundle sheaths regulate the movement of substances between the vascular tissue and the parenchyma and, in leaves, protect the vascular tissue from exposure to air.