Pleurotaenium truncatum
Image © Alfred van Geest

Pleurotaenium truncatum. Notice relatively large cell dimensions (particularly the cell breadth) and semicells distinctly tapering toward the apex.

Cell dimensions (L x B): 390 x 63 µm

 

 

Desmid of the month
May 2014

Pleurotaenium truncatum

Pl. truncatum is a large-sized, stout Pleurotaenium species. Semicells are only slightly inflated at their base. From that base toward about half-way there lateral margins are more or less parallel or slightly divergent, and then they distinctly taper toward the apex. The relatively narrow apices are furnished with a whorl of granules that are not very pronounced (sometimes even almost completely reduced). In the Netherlands, Pleurotaenium truncatum is rather common in mesotrophic quivering fen hollows, but elsewhere it is rare.

Image © Alfred van Geest

Another cell of Pl. truncatum showing an even stronger tapering to the apices.

Image © Henk Schulp

Cell of Pl. truncatum showing longitudinal, parietal chloroplast bands, terminal vacuole  and a brownish ring at the isthmus expressing the overlapping part of the walls of the two semicells (not particularly specific for this species).


Image © Alfred van Geest

Pl. truncatum. Detail of semicell apex showing whorl of (relatively discrete) granules.