Species: Cell body spherical in shape (sometimes broaden), 12-22(-27) μm in diam.; papilla absent; chloroplast cup-shaped, with a large anterior concavity; a single spherical pyrenoid located at posterior half of the cell body; stigma elongated in shape, longitudinally located at equatorial line or slightly anterior; nucleus at anterior. [var. macropyrenoidosa Ettl 1965]: Pyrenoid large, ellipsoidal in shape; stigma elliptical or narrowed spot (Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).