- xylem ray; wood ray
- The height of uniserial wood ray of p.armand was one to eighteen cells and that of p.prokoraiensis was one to sixteen cells.
- Wood rays of p.armand and p.prokoraiensis on tangential section both had two shapes that was uniserial wood ray and spindle wood ray.
- The result shows that woody ray with rich rhombus or square crystals is only seen in two species including acer trialum and acer cappadocicum among18species and idioblast cells in woody ray are obvious characters different from the other species of acer genus which have been researched.
- Thickness of upper and lower epidermis of leaves width of xylem and phloem of annual and biennial branches ratio of late wood to early wood periderm thickness of biennial branches and length of xylem ray present decreasing trends with latitude ascending; while ratio of palisade tissue to spongy tissue epidermis thickness of annual branches and cortex thickness of biennial branches show unobvious variations with latitude increasing.