Desmid of the month
March 2019

Staurastrum arachne

Cells of St. arachne usually are 5-radiate, with slender, convergent processes that remind us of the legs of a spider. In apical view, the processes tend to be bent in one and the same direction (clock-wise or anticlockwise). Contrary to the processes that are furnished with regular series of denticulations the semicell body is unsculptured except for the very apex and, sometimes, also the very base.
In the Netherlands, St. arachne is only known from a few finds in oligotrophic moorland pools that date from the first half of the last century.