Description: The cells are (4)–5–7–(8) times longer than they are wide, evenly curved and continuously narrowing towards the rounded cell ends. The cell wall is delicately striated to almost smooth, without girdle bands. The pyrenoids are arranged more or less in a row along the cell axis, which, in addition to the smaller dimensions, distinguishes this species from the morphologically similar Closterium ehrenbergii. The pyrenoids are numerous and scattered.

Dimension: Length (170)–200–350–(450) µm, width (28)–35–55–(70) µm.

Occurrence:  Widely found in ponds and lakes, backwaters and the like, occasionally also in plankton.

Left: Original graphic by Prof. Lenzenweger.
Right: Photomicrograph by Prof. Lenzenweger. For microphotography, the microscope illumination was adjusted in such a way that as many features as possible that are important for species identification are prominently displayed.

Copyright by Prof. Rupert Lenzenweger, Ried im Innkreis, Austria.