Desmid of the month
August 2011

Xanthidium basidentatum

Xanthidium basidentatum differs from the allied species X. cristatum (desmid of March 2008) and X. fasciculatum (desmid of August 2010) by a more exuberant ornamentation. Each of the semicell angles is beset with a bundle of spines. In addition to that there is a number of marked granules near each of the basal angles. In the Netherlands X. basidentatum is a very rare species, encountered in acidic, mesotrophic moorland pools.

Image © Christophe Brochard

Same cell of X. basidentatum photographed at lower magnification, showing the bundles of spines at each of the semicell angles.

mouse-over image © Alfred van Geest

Cell of X. basidentatum in apical view

mouse over fimage © Christophe Brochard

Cell of X. basidentatum. The cell wall in the centre of the semicell is furnished with a circle of granules. At each of the angles a number of stout spines is inserted. Notice also the additional granules near the basal angles.

Cell dimensions (L x B): 82 x 75 µm

Image © Alfred van Geest

Xanthidium basidentatum from another Dutch population.

Image © Alfred van Geest

Cell of X. basidentatum in lateral view