So far, I have only found Staurastrum muticum var. muticum in the Schwemm Moor in Austria. The species is small and inconspicuous. It has no spines or conspicuous granules. The semi-cells are approximately oval and the sinus is widely open. In apical view, the cell is 3-radiate with slightly concave indentations. At 21 µm in length, the specimen shown below is at the lower end of the range of 20-31 µm given by Lenzenweger (1997).

The similar species Staurastrum bieneanum var. bieneanum is somewhat larger, with a length of 30–32 µm, and the semi-cells have sharper lateral angles, resulting in a shape similar to a rugby ball.