Image © Marien van Westen

Staurastrum punctulatum. Notice sinus widely opening from an about rectangular apex. Semicells with broadly rounded angles.

Cell dimensions (L x B): 30 x 25 µm

 

 

Desmid of the month
September 2017

Staurastrum punctulatum

St. punctulatum belongs to the group of Staurastra the cell wall of which is fairly uniformly beset with granules. In St. punctulatum those granules are rather coarse and not seldom a bit flattened. In outline, cells of St. punctulatum are somewhat hour-glass-shaped, so longer than broad and with a widely ending sinus. The semicell angles are broadly rounded. In the Netherlands, St. punctulatum is widely distributed and pretty common in acidic bogs and moorland pools.

Image © Marien van Westen

Staurastrum punctulatum. Empty semicell in apical view showing relatively coarse, broadly rounded granules.

Image © Marien van Westen

Cell of Staurastrum punctulatum showing an even distribution of cell wall granules.


Image © Marien van Westen

Couple of St. punctulatum cells sticked together after division.