Xanthidium cristatum. Notice that the spines at the apical angles and the upper lateral angles are in pairs (not all in focus), but those at the lower lateral angles are single.

Cell dimensions (L x B): ca 80 x 70 µm

 

 


Desmid of the month
March 2008

Xanthidium cristatum

Xanthidium cristatum differs from the commoner and better known species X. antilopaeum in that its semicells are octogonal in outline, instead of hexagonal. Whereas  the apical and upper lateral semicell angles are furnished with two spines each, the lower lateral angles bear just a single spine. In the Netherlands, X. cristatum is of occasional occurrence in mesotrophic habitats, in particular quaking fen hollows.

 

Cells of Xanthidium cristatum in differential interference contrast (DIC) displaying a mucilaginous extracellular envelope.