Genus: Colonies of a fixed number of cells, flat, circular in shape; cell body polygonal in shape, with horn-like projections; cell wall garanulated, wrinkled or notched; chloroplasts plate-like or reticular; asexual reproduction by zoospore; sexual reproduction by isogametes (Illustrations of The Japanese Fresh-water Algae, 1977). Species:

31 μm 63 μm 94 μm; x 640

Pediastrum boryanum (Turpin) Meneghini, 1840: Colonies of 8, 16, 32 cells; no space between adjacent cells; a pair of horn-like projections; cell wall covered with fine granules; cell body 13-18 μm diam. (Illustrations of The Japanese Fresh-water Algae, 1977).