Subgenus: Entomum (Apical area deeply indented or notched)
Section: Incisa (Cell surface smooth; apical area without spiny projections)
Species: Cell body μm long, μm wide, L/W=,
isthmus μm wide;
(Illustrations of The Japanese Fresh-water Algae, 1977).
Euastrum ampullaceum Ralfs,
cell body μm long, μm wide, L/W=,
x 640, No. 3, Miyatoko marsh, Minami-Aizu town, Fukushima Pref., Japan, June 15, 2008 by Y. Tsukii 31 μm
63 μm
94 μm; x 640
Images of collecting locality:
No. 3, Miyatoko marsh, Minami-Aizu town, Fukushima Pref., Japan, June 15, 2008 by Y. Tsukii