Description: The cells are (1.5)–1.7–1.9–(2) times longer than wide. The cell shape shows a double trapezoid, each trapezoid is vaguely separated in 2 lateral lobes by thin emarginations on the edges. The surface of the cell half shows 5 swellings and a pore at the center. The central lobes (vertex lobes) are broadened at the ends and have a fine cut in the middle. The cell wall is subtly punctuated by tiny pores. The chloroplasts have several pyrenoids.

Dimension: Length (95)–120–140–(170) µm, width (55)–65–75–(95) µm.

Occurrence: Widely spread in fens and transitional mires with acidic and moderate acidic waters, sometimes abundant.

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.