According to Esau, the primary vascular system ofthe stem of Eucommia ulmoides is a traces system, while at the same timethe structure of the stem nodes prossess the features of unilacunar gap andone trace.

• 参照Esau的观点,杜仲茎的初生维管系统应属于叶迹系统,而其节部结构的特征为单叶隙、单叶迹。