Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal, ellipsoidal or spindle-shaped; zygospores formed outside of mother cells (Illustrations of The Japanese Fresh-water Algae, 1977) Subgenus: lacks arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977) Species: Cell body 31-47 μm long (excluding spines), 31-47 μm wide, L/W=1.25, isthmus 11-15 μm (Illustrations of The Japanese Fresh-water Algae, 1977)

31 μm 63 μm 94 μm; x 640

Staurastrum hirsutum (Ehrenberg) Brébisson or S. monticulosum Brébisson var. bidens W. et G.S. West ?, cell body μm long, μm wide, L/W=, isthmus μm wide, x 640, No.4, Kuroyachi marsh, Hachimantai, Hachimantai city, Iwate Pref., Japan, August 23, 2007 by Y. Tsukii
31 μm 63 μm 94 μm; x 640

Cell body μm long, μm wide, L/W=, isthmus μm wide, x 640

Images of collecting locality: No.4, Kuroyachi marsh, Hachimantai, Hachimantai city, Iwate Pref., Japan, August 23, 2007 by Y. Tsukii