Genus: Filamentous algae without branching, no rhizoids, covered with gelatinous sheath;
cell body cylindrical or ellipsoidal, cells attached side by side or separated;
a single chloroplast band-form, with a pyrenoid
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Images of collecting locality:
No.1, Iyari marsh, Omachi city, Nagano Pref., Japan, June 4, 2007 by Y. Tsukii