包括根或茎的维管组织及相关薄壁组织，若有维管束鞘和内皮包被则这二者也属于中柱结构。

Stele the vascular tissue and associated parenchyma tissue and (if present) the surrounding pericycle and endodermis of a stem or root.

youdao

该植物茎与根茎的构造相似，均有表皮、皮层、淀粉鞘、周维纤维、六束维管束、髓及髓射线。

Having the epidermis, cortex, starch sheath, perivascular sclerenchyma, six vascular bundles, pith and pith ray, the stem is similar to the root in their structure.

youdao

尽管薇甘菊叶片为典型C3植物特征，结果发现了茎以及主叶脉内存在类似C4途径的、具有丰富叶绿体的维管束鞘结构。

Although leaf photosynthesis of this weed is of the C3 type, a C4-like vascular bundle full of chlorophyll was observed in the main vein of the leaf and young stems.

youdao