Genus: Cell body crescent in shape (long, curved, tapered at both ends); cross section rounded;
cell wall smooth or with longitudinal lines, bands on the cell wall in some species;
chloroplast laminae ridged and radially arranged, which makes cross section star-shaped;
pyrenoids aligned or scattered (Illustrations of The Japanese Fresh-water Algae, 1977).
Closterium ehrenbergii Meneghini var. ehrenbergii: Cell body large, swelled at center, tapered at both termini, 150-(176-323)-380 μm long, 15-(20-28)-40 μm wide, L/W= 4-6; cell wall smooth, colorless, with no bands; 5-8 pyrenoids in each chloroplast (Illustrations of The Japanese Fresh-water Algae, 1977).