Fig. 7.2-12a. Transverse section of grape stem (Vitis). This micrograph shows the bordered pits of an angiosperm in transverse section. Whereas the bordered pits of pine (Fig. 7.2-11) are comparatively large and easy to see, those of angiosperms are small and difficult to see. This is an excellent section (made by Triarch) in which the wide scalariform pits are actually easy to see (they almost never are as obvious as this). Each pair of arrows marks the end points of the pits, and the fine white line located between the arrows is the pit chamber; the pit membrane is not visible. Being angiosperms, there is no torus stuck to a pit aperture.