“bundle sheath”簡單造句，bundle sheath造句子

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 .

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