Genus: Filament without branching; cell body cylindrical; two chloroplasts star-shaped; tubes formed (or cell body fused) at conjugation; zygospore spherical or broad ellipsoidal formed within female gametangium (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species:

31 μm 63 μm 94 μm; x 640

Zygnema excompressum Transeau: vegetative cells 32-80 μm long, 23-26 μm diam., 2 chloroplasts in each cell