Observations on Staurastrum polonicum

Description: The cells are up to 1.4 times longer than wide. The cell halves are rounded off sexangular in shape with bulged out sides and broadly truncated vertex. Around the basis of the cell halves there is a ring of tiny spherical calottes. The central cuts are far opened towards the periphery. The vertex view is circular with 8 to 9 shallow waves. Another ring of such bulges leads around the vertex center. The cell wall is closely covered by tiny warts.

Dimension: Length 45–65 µm, width 35–50 µm.

Occurrence: In slightly acidic moorland waters and silting zones of lakes. Worldwide distribution.

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.