Species: Trichome straight, without constriction at cell-cell junction, 8-9 μm wide; cell body short, 2-4 μm long, L/W=1/4-1/2; granules absent along septum; terminal cells semicircular (Illustrations of the Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Chuo-bashi (Central bridge), Oura central park, Oura town, Gunma Pref., Japan, February 2006 by Y. Tsukii