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)
Subgenus: lacks arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977)
Species:
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f. spinosa :
S. furcatum
f. spinosa
26 x 27 μm
Iroha-numa
Zao mountain
Yamagata, 2005
S. furcatum ?
f. spinosa
26 x 27 μm
Tashirodaira m.
Hakkoda mountain
Aomori, 2005
S. furcatum
f. spinosa
33 x 30 μm
near Iroha-numa
Zao mountain
Yamagata, 2006
S. furcatum
f. spinosa
31 x 27 μm
Kodanuki marsh
Fujinomiya
Shizuoka, 2006var. subsenarium :
S. furcatum
v. subsenarium
stock Tnk-5
Numappara marsh
Kuroiso
Tochigi, 2003
S. furcatum
v. subsenarium
stock Mfk-1
Kejo-numa
Furukawa
Miyagi, 2003