Desmid of the month
December 2008
Penium spirostriolatum
Penium spirostriolatum differs from P. margaritaceum (desmid of March, 2004) by its cell wall sculpture consisting of longitudinal, more or less spiralized ridges (instead of scattered granules). Cells are roughly cylindric in shape and display distinct girdle bands. In the Netherlands P. spirostriolatum is of occasional occurrence in slightly acidic, mesotrophic moorland pools and fen hollows. Zygospores have been encountered a few times.
Image © Marien van Westen
Cell of Penium spirostriolatum (var. amplificatum). Notice cell wall girdle bands marked by irregular transitions in the cell outline.
Cell dimensions (L x B): ca 180 x 20 µm
