Desmid of the month
December 2007

Cylindrocystis gracilis

Like in Cylindrocystis brebissonii cells of Cylindrocystis gracilis are cylindric in shape with broadly rounded ends. However, whereas the chloroplasts in C. brebissonii are provided with ridges that, from a central core, radiate in all directions, the chloroplast ridges in C. gracilis run more or less parallel in a longitudinal direction. Cylndrocystis gracilis was described by Ilse Hirn (1953). As an additional diagnostic characteristic (against C. brebissonii) she found a different  stainability of cell sap when treated with specific dyes. In the Netherlands C. gracilis is locally of abundant occurrence in (semi)emersed  Sphagnum vegetation.


Hirn, I., 1953. Vitalfärbungsstudien an Desmidiaceen. — Flora 140: 453-473.

Cell of Cylindrocystis gracilis (in different focus). Notice the longitudinal chloroplast ridges.

Cell dimensions (L x B): 40 x 13 µm.



Mixed cuultures of C. gracilis and C. brebissonii. Vital staining with toluidine blue colouring cell sap in C. brebissonii bluish, that in C. gracilis purple.