Genus: Trichome without mucous sheath; straight, long, consisting of numerous cells (Illustrations of The Japanese Fresh-water Algae, 1977). Species: Trichome dark-blue in color, nearly straight, without constriction at cell-cell junction, 6-11 μm wide; cell body reddish blue in color, 4-11 μm long (1/4-1/2 of its width); granules present along septum; cell wall of the terminal cells thick (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No.3, Kashibaru marsh, Karatsu city, Saga Pref., Japan, November 22, 2006 by Y. Tsukii