Xanthidium armatum

Image © Wim van Egmond

Cell of Xanthidium armatum(in frontal view) marked by stout, furcate spines on the angles.

Cell dimensions (L x B): 150 x 100 µm.

 

 


Desmid of the month
January 2006

Xanthidium armatum

Xanthidium armatum is a conspicuous desmid that is readily to be recognized. In frontal view, semicells are about octangular in outline and marked by stout, bi-or trifurcate spines on the angles. The semicell centre is somewhat inflated and furnished with a corona of simple or bifurcate teeth. In the Netherlands, X. armatum is confined to oligotrophic habitats where there is a slight input of minerals from the subsoil. As a consequence of the highly acidified precipitation in the last century its occurrence is much decreased. Today it is a rare species.

Cell of X. armatum in lateral viewImage © RIZA

Cell of X. armatum in lateral view. Notice the corona-shaped central inflation in each of the semicells.

Xanthidium armatum, central coronaImage © RIZA

Cell of X. armatum in frontal view focussed on the central corona.

Xanthidium armatum, a couple of daughter cellsImage © Wim van Egmond

A couple of daughter cells of X. armatum.

Notice the primary cell wall just shed off by the younger semicells.