Nuclei are prominent in the thin peripheral cytoplasm. Sclereid under construction. Note the similarity in shape to the Parenchyma cell above. However, note the difference in wall thickness. The new wall is called Secondary and is deposited after the cell has ceased enlargement.
Parenchyma cells can eventually develop into Sclerenchyma cells.
However, this is not usually the case. The distinguishing features of Sclerenchyma are the presence of a thick Secondary wall which is highly organized, and usually contains Lignin. Viewed with Phase optics. SEM Photo of a cell like the one above. The largest organelle is the Nucleus.