Species [ var. turgidus ]: Cells bright blue-green, sometimes coarsely granulated,
8-32 μm in diam. (without sheath), sheaths 2-6 μm in thickness
(Photomicrographs of the Freshwater Algae, vol. 3, 1985).
Colony of 2-4 cells, covered with layered gelatinous sheath; cell body 8-32 μm in diam. (excluding sheath), 13-40 μm in diam. (including sheath).
[ var. maximus ]: Cell body 22-45 μm in diam. (excluding sheath, 5-10 μm in thickness)
[ var. thermalis]: Sheath present, but not layered (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
No. 5, Shijuhachi-ike (pond), Shiga highland, Yamanouchi town, Nagano Pref., Japan, June 1, 2006 by Y. Tsukii