Fig. 7.3-2. Transverse section of wood of Menispermum (a vine called moonseed that is occasionally cultivated). This transverse section has caught a simple perforation plate that lies parallel to the plane of sectioning. The rim of the plate is indicated between the two arrows, and the perforation is the entire circular white area. The rim so narrow that a first impression is that this is just an ordinary vessel element or maybe one with a slightly thicker wall: it would be easy to accidentally think that the perforation is the entire lumen of the element.