Genus: Filamentous algae without branching; a single plate-like chloroplast in each cell (Illustrations of The Japanese Fresh-water Algae, 1977). Species:

31 μm 63 μm 94 μm; x 640

Images of collecting locality: a small marsh near prefectural road route 342, Sukawa highland, Kurikoma mountain, Higashi-naruse village, Akita Pref., Japan, June 24, 2007 by Y. Tsukii