Subgenus: Eustaurastrum
Section: Processiformes
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.
Subgenus: with arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977)
Section: Arm-like projections granulated or dented
3 arm-like projections 
S. dorsidentiferum
5 samples
49-50 μm
2001-2008
S. anatinum ?
7 samples
μm
2001-2007
S. longiradiatum
v. breviradiatum
30 x 60 μm
Murakuni ike
Iwatsuki-bunka p.
Saitama, 2006
S. sebaldi
4 samples
73-82 x 80-90 μm
Norikura highland
2005-2008
S. pseudosebaldi
29 samples
25-53 x μm
1998-2008
S. inflexum
2 samples
x 40 μm
2004-2006
S. polymorphum
11 samples
16 x 23-27 μm
2004-2008
S. vestitum
4 samples
x 35-60 μm
2006-2008
S. oxyacanthum
30 x 55 μm
water reservoir
near Yamaguchi Univ.
Yamaguchi, 2004
Staurastrum sp.
μm
Uruguay, 1999
Staurastrum sp.
μm
Umi-no-nakamichi
Fukuoka, 2001
S. gracile
12 samples
18-26 x ?-60 μm
1999-2006
S. gracile
f. subtenuissimum
22 x 26 μm
Shimo-no-koike
Shiga highland
Nagano, 2004
S. gracile
v. coronulatum
μm
USA, 1999
S. gracile ?
x 30 μm
Japan, 1998
Staurastrum sp.
μm
Otto-Numa
Ibaraki, 2002
S. aculeatum
5 samples
1998-2007
S. arcuatum
μm
in preparation
Numappara
Tochigi, 2003
S. iotanum
18 samples
2- or 3-arms
19-29 μm
2001-2008
Staurastrum sp.
30 x 35 μm
water reservoir
near Yamaguchi Univ.
Yamaguchi, 2004
S. tetracerum
f. trigona ?
13-20 x μm
6 samples
2001-2007
