Palm wood from Schoonebeek (NL)
Microphoto of a vascular bundle with surrounding parenchyma tissue.
Height of the bundle 0.9 mm.

The large white spot (the transverse section of a tube) is empty, but for the rest the cell structure has been preserved very well. The empty part has been full with sclerenchyma cells (cells with very thick walls). Above the sclerenchymatic cap, which serves for giving stiffness to the trunk, the real vascular part can be seen. The white spots in it (two in most cases) are wood vessels. They are surrounded by a great number of waterconducting cells (tracheids).
Inside the vascular part, bordering the sclerenchyma cap, are the sieve tubes (the phloem), managing the food transportation from the leaves to the rest of the plant. The vascular bundle, including the sclerenchyma cap, is bedded in the ground tissue (parenchyma: thinwalled cells), which looks different in different species of palms. In this case elongated cells are growing perpendicularly to the bundle. In many other species this is not the case.
Slide nr. 380 from a piece of palm wood from Schoonebeek. Palm wood coll. F. Rhebergen, slide coll. J. van der Burgh.