Genus: Filament without branching; cell body cylindrical; one or several chloroplasts band-shaped, spirally arranged within the cell, pyrenoids present; septum with or without folded structure (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). About 300 species (Illustrations of The Japanese Fresh-water Algae, 1977).
Species:
S. sp.7
4 beaded chl. ?
160-325 x 25 μm
Japan, 1998
S. sp.7b
4 beaded chl. ?
x μm
Saitama, 1999
