Family: Cell wall with 2 or more partitions.
Subfamily: Cell division occurs at central constriction.
Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal, ellipsoidal or spindle-shaped; zygospores formed outside of mother cells (Illustrations of The Japanese Fresh-water Algae, 1977).

Prostaurastrum (腕状突起がない)
S. muticum μm	Staurastrum sp.11 μm	Staurastrum sp.12 μm	Staurastrum sp.13 μm
Eustaurastrum (腕状突起がある)
S. leptocladum Two arms: μm	S. gracile Three arms: μm	Staurastrum sp.14 Three arms: μm	Staurastrum sp.16 v μm
Staurastrum sp.3 Four arms: μm	Staurastrum sp.4 Four arms: μm	Staurastrum sp.5 Four arms: μm	Staurastrum sp.6 Four arms: μm
Staurastrum sp.7 Four arms: μm = sp.4 ?	Staurastrum sp.15 Five arms: μm	Staurastrum sp.9 Five arms: μm	Staurastrum sp.10 Six arms: μm