Anatomical Study on the Secondary Vascular Tissue of Stem of Bothrocaryum controversum

The secondary vascular tissue in the stem of Cornus Controversa Hemsl was studied. The resuits showed that the structure of wood was diffuse-porous wood, the growth ring of which was obvious. There was scalariform performtion plate in the end wall of the vessel. The number of bar latch was 18 which was parallel or dichotomous branching from the middle part. Most xylem rays were helergeneous Ⅱ , xylem parenchyma was diffuse parenchyma and was rarely partracheal parenchyma.