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: Vegetative cells 64-192 μm long, 42-58 μm diam., 3-4 chloroplasts making 1.5-4 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

50 μm 100 μm 150 μm; x 400

* Spiryogyra distenta Transeau: Vegetative cells (50-) 58-165 μm long, (43-) 48-58 μm diam., 2 chloroplasts making 2-3.5 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

* Spiryogyra occidentalis (Transeau) Czurda: Vegetative cells 125-300 μm long, 40-50 μm diam., 1-2 or 3 chloroplasts making 1-2.5 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

Spiryogyra porticalis Müller Cleve: Vegetative cells 66-200 μm long, 40-50 μm diam., 1 chloroplast making 3-5 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

Spiryogyra ternata Ripart: Vegetative cells (48-) 85-330 μm long, (55-) 60-85 μm diam., 3-4 chloroplasts making 1-3 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

Spiryogyra pulchrifigurata Jao: Vegetative cells 64-192 μm long, 42-58 μm diam., 3-4 chloroplasts making 1.5-4 turns in each cell (Illustrations of The Japanese Fresh-water Algae, 1977).

Spiryogyra majuscula Kützing: Vegetative cells 68-190 μm long, 50-80 μm diam., 5-8 chloroplasts making 0 turns in each cell or slightly curved (Illustrations of The Japanese Fresh-water Algae, 1977).