Cosmarium granatoides. Notice semicells consisting of a 2-undulate, about rectangular basal part and a domed apical part.

Cell dimensions (L x B): 18 x 12 µm

Image 3 © Wil Leurs



Desmid of the month
September 2021

Cosmarium granatoides

The name of this small-sized species suggests resemblance to C. granatum. Yet, it is readily to be distinguished in that the lateral sides of the semicell are distinctly undulate contrary to those in C. granatum. Actually, in C. granatoides each semicell consists of a 2-undulate, about rectangular basal part passing by way of a slight indentation into a highly domed apical part. In the Netherlands, C.  granatoides is only known from a few swampy sites in the island of Schiermonnikoog (2003, 2019) and 'Amsterdam Waterleidingduinen' (2016), but it may be easily overlooked.  

Three other cells of C. granatoides showing some morphological variation.