Developmental anatomy on the stem and leaf of Bupleurum chinense DC.

Aim To study the developments of Bupleurum chinense DC.stem and leaf.Methods Paraffin sectioning.Results The development of Bupleurum chinense DC.stems could be divided into four stages:promeristem,primary meristem,primary structure and secondary growth stage.Promeristem was composed of two layers of tunica cells and a group of corpus cells,with the development of promeristem,the primary meristem including protoderm,procambium and ground meristem,formed at the apex of the shoot.The primary meristem differentiated into primary structure consisting of epidermis,vascular system,cortex and pith.With the progressive development of stem,the activity of vascular cambium began,the fascicular cambium differentiated into secondary xylem and secondary phloem,while the interfascicular cambium only differentiated into wide ray of parenchyma tissue.But the cork was not fount to form in the stem from beginning to end in its whole life.However,the development of Bupleurum chinense DC.leaves could be divided into three stages: promeristem,primary meristem and mature structures.The leaf of Bupleurum chinense DC.was the typical bifacial leaf composed of blade and stipe.The secretory canals mainly were distributed not only in the cortex and pith of the stems,but also in the tissues lying above and under the vascular bundles of the leaves.Moreover,they were all primary ones.Conclusion The developments of Bupleurum chinense DC.stem and leaf were similar to the general developmental laws of the etesiae dicotyledon's.