Staurastrum brebissonii
Image © Alfred van Geest

Staurastrum brebissonii. Notice open, acutely-angled sinus, subelliptic outline of semicells and cell wall equally covered with closely set, short spines.

Cell dimensions (L x B): ca 34 x 40 µm

 

 

Desmid of the month
May 2016

Staurastrum brebissonii

Cells of St. brebissonii are about as long as broad, with an open, acutely-angled sinus. Semicells are subelliptic to rhomboid in outline with broadly rounded angles. The cell wall is equally set with short spines that are arranged in concentric series around the angles. In the Netherlands, St. brebissonii including its var. ordinatum* is of occasional occurrence in various slightly acidic, mesotrophic water bodies.

* Synonymous with Staurastrum erasum, see flora Coesel & Meesters (2013).

Staurastrum brebissonii var. ordinatumImage © Marien van Westen

Another cell of St. brebissonii, to be accounted var. ordinatum (characterized by semicell lobes that are more or less upwardly directed).


Staurastrum brebissonii, empty semicellImage © Marien van Westen

Empty semicell of St. brebissonii in apical view showing arrangement of cell wall spines in concentric series around the angles.