Desmid of the month
March 2011

Closterium striolatum

Cl. striolatum belongs to a group of Closterium species the cell wall of which is marked by so-called girdle bands (intersectional segments). Cells of Cl. striolatum are only slightly curved, in the midregion often straight, towards the ends gradually attenuated. Cell ends are truncately rounded and often slightly widened (capitate). The cell wall is distinctly striate and often brownish coloured. In the Netherlands, Cl. striolatum is one of the most common species in (highly) acidic, oligotrophic bogs and moorland pools. Zygospores, on the contrary, are but seldom encountered.

Closterium striolatum, detail of cell end


Cell of Closterium striolatum. Notice straight midregion and truncately rounded apices.

Cell dimensions (L x B): 330 x 34 µm



Detail of cell end. Notice slightly capitate apex with terminal vacuole holding some two crystals.




Detail of midregion. Notice girdle bands (marked by transversal sutures) and longitudinal striation of the cell wall.



Closterium striolatum, detail of midregion with girdle bands



Globose, smooth-walled zygospore of Closterium striolatum. Notice also girdle bands in the brownish coloured, empty gametangial cells.




Closterium striolatum, zygospore
Closterium striolatum, algal bloom


Algal bloom of Cl. striolatum