Genus: Unicellular; cell body ellipsoidal or spindle-shaped, attached on a substrate at one end;
a single chloroplast plate-like in shape, with a pyrenoid
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Species: Cells 40-70 μm long, (17-)20-33 μm wide, L/W up to 3; symmetrical, pear-shaped or obovoid, with a short, thick stalk; apex obtuse or silghtly acute and thin-walled (The Freshwater Algal Flora of the British Isles 2002).
Images of collecting locality:
Tsuki river (exit of drainage ditch), upstream of Yanagimachi bridge, Aoyama/Shimozato, Ogawa town, Saitama Pref., Japan, November 25, 2007 by Y. Tsukii