No perforation plate between contiguous tracheary elements in junction of two veins

Shown is the junction area of two perpendicular veins in tropical nettle (Dendrocnide moroides). Two (1 & 2) helical tracheary elements are separated by continuous swollen permeable wall of cellulosic microfibers (arrow). No perforation plate is present. Of greatest interest is the juncture between the radial tracheary element (1), with that of the axial tracheary element (2).