Cell of Staurastrum dilatatum in frontal view. Notice rhomboid outline of the upper semicell.
Cell dimensions (L x B): ca 40 x 40 µm
Staurastrum dilatatum is affiliated to S. alternans but cells are distinctly stouter whereas the outline of the semicell in frontal view is more or less rhomboid instead of subelliptic-subtriangular. In apical view, cells of S. dilatatum are 4-5-radiate (versus 3-radiate in S. alternans). In the Netherlands, S. dilatatum is of occasional occurrence, particularly in slightly acidic, mesotrophic fen hollows.