Genus: Two chloroplasts plate-like or slightly spiralled;
a nucleus centrally located between the chloroplasts; mostly unicells, filaments rare
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species [ var. pilosum ]: Cell body cylindrical 177-(180)-300 μm long, 10.5-15-(15.5) μm wide, L/W = 12-20, cell wall with fine hairy projections, both ends not swelled.
[ var. echinatum ]: Cell body narrower than v. pilosum, 96-140 μm long, 5-(5.5-7.5) μm wide, L/W = 15-20, (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
waterfield between Kita-Omachi station and Nogu river, Omachi city, Nagano Pref., Japan, June 4, 2007 by Y. Tsukii