| 1. | The stems and rhizomes were observed to differ in cortex - cell layer , perivascular fiber - ring presence , vascular cylinder and pith proportions , vascular bundle number and secondary growth and these differences were associated with their own physiological functions 地上茎和根状茎之间在皮层细胞层数、周维纤维柱的有无、维管柱和髓所占比例、维管束束数、次生生长等方面存在差异,这些差异与它们各自担负的生理功能相关联。 |