Tissue identification in vascular bundle sections?

Question

I always have trouble differentiating the tissues in a vascular bundle. I specially cannot properly identify the vascular cambium and phloem. I know xylem vessel elements are large cells with thicker cell walls, that makes them clearly different from other cells in the vascular bundle. However, the difference between vascular cambium cells and phloem cells is unclear. I would like to know how I can identify these tissues accurately. A photomicrograph with marked borders would be appreciated along with explanation of cell appearance in these tissues. Thank you a lot.

Answer 1

"I specially cannot properly identify the vascular cambium and phloem."

In my search, I completely agree that they are very difficult to distinguish which is which in many slides. Some slides are stained so you can distinguish the vascular cambium as the layer between the xylem and phloem. Take a minute and look at slide 9 on this link:

https://www.slideshare.net/EasyBiologyClassEBC/vascular-bundles-structure-and-classification-different-types-of-vascular-bundles-plant-anatomy-by-easybiologyclass

Make sure you enlarge the PowerPoint to se the slide.

As a note for those of you who are also ready this:

1. "Xylem up, Phloem (pronounced flow-um) down" is a memory tool to remember the water and dissolved nutrients flow up from the roots through the xylem and the sugar (made in the leaves) dissolved in water "flows down" the phloem to feed the rest of the tissues and store excess sugar in the roots.
2. Primary growth (growing up) happens at the tip of the branches and secondary growth (growing out) occurs in the vascular cambium. This is mentioned earlier in the above question. It is the layer between the xylem and phloem.