Subgenus: Atomum (Apical area slightly depressed)
Section: Retusa (Cell body large; granulated dome(s) at the center of each semicell)
Species: Cell body 64.5-75.3 μm long, 56-64.5 μm wide,
constriction 14-17 μm wide
(Illustrations of The Japanese Fresh-water Algae, 1977).
Euastrum spinulosum var. inermius Nordstedt,
cell body μm long, μm wide, L/W=, isthmus μm wide,
x 640, Water field near Bungo-Mori railway station, Kusu town, Oita Pref., Japan, September 8, 2008 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
Water field near Bungo-Mori railway station, Kusu town, Oita Pref., Japan, September 8, 2008 by Y. Tsukii