Species: Cell body broad ellipsoidal or nearly spherical, 18-35 μm in diam.;
papilla broad with flattened apex; chloroplast cup-shaped; a pyrenoid horseshoe-shaped, located
beneath equatorial line or slightly posterior; stigma longitudinally elongated, thin,
located at equator or slightly anterior; nucleus at anterior half of the cell body. |
[ var. globulifera (Korschikoff) Korschikoff 1938]: Papilla narrower and more protruded; cellwall thick; with several pyrenoids irregular in shape.
[ var. perforata Vlk 1940]: Pyrenoid ring-form.
[ var. longirubra Ettl 1976]: Stigma large, elongated, stick-like in shape, longitudinally located at anterior half of the cell; papilla more broad and short; a pyrenoid elongated, curved as half-ring
(Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).