Family: Chloroplasts plate-like or ribbon-like; sexual reproduction by isogamy.
Genus: Without gelatinous sheath; filaments consist of many cells; rhizoid formed at one end
(Illustrations of The Japanese Fresh-water Algae, 1977).
cell body 9-18 μm long, 6 μm wide, with two parietal chloroplasts, pyrenoids present,
x 640, Sayama Natural Park, Higashi-murayama city, Tokyo, Japan, December 2001 by Y. Tsukii
94 μm; x 640