bundle sheath造句怎么写

Palisade tissue is rich in saliferous vacuoles, while vascular bundle sheath is obvious.

The vascular bundle consists of vascular bundle sheath, xylem, phloem and big parenchymatous cells.

There are 2-3 layers of long-column-shaped palisade tissue under the upper epidermis, and there are a great number of mechanical tissues which made up of vascular bundle sheath .