Tetradesmus wisconsinensis G.M. Smith: Colonies of 4 (or 2 or 8) cells, free-floating; cell body crescent in shape, both ends pointed, 4-5 μm wide, 12-18 μm long; cells attached each other at their convex side, arranging parallel in side view, and radial in top view; a single chloroplast parietal, plate-like, with a pyrenoid (Photomicrographs of the Fresh-water Algae, vol. 1, 1984).