Subgenus: Entomum (Apical area deeply indented or notched)
Section: Incisa (Cell surface smooth; apical area without spiny projections)
Species:
(Illustrations of The Japanese Fresh-water Algae, 1977).
Euastrum denticulatum (Kirchner) Gay var. denticulatum ?,
cell body 25 μm long, 19 μm wide, L/W=1.3, isthmus 4 μm wide,
x 640, Dojo-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii
31 μm
63 μm
94 μm; x 640