Anatomical Structure and Development of Aerial Adventitious Roots of Taxus Chinensis Var.Mairei

The anatomical structure of the aerial adventitious roots of Taxus chinensis var.mairei.was investigated in this paper.We have observed the following characteristics of anatomical structure and development:(1) The primary roots belong to archetype and the lateral roots occur in the position toward the xylem of the vascular cylinder;(2)The root endodermis consists of thicken casparian strips,and there are from two to four layers parenchyma cells near the pericycle;(3) the pith and resins canals are absent in the toots;(4)Secondary structure occurs in the root hair zone,and vascular cambium is formed from the parenchyma cells between the primary xylem and primary phloem;(5)Tanning materials are abundant in pericycle cells and phelloderm cells;(6)Sclereids are found in secondary phloem,and rays are rather rich in secondary xylem.