Home / Charophyceae / Desmids / Unicells/ Placoderm / Penium
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Name derivation:
Classification:
Penium Brébisson ex Ralfs in Ralfs 1848; 24 of 137 species descriptions are currently accepted taxonomically (2013). Order Desmidiales; Family Peniaceae
Morphology:
Cylindrical unicells up to 450 µm long with truncate or somewhat rounded end walls. Isthmus nearly as wide as the hemicells, only slightly ‘incut’.
Similar genera:
Several genera of cylindrical placoderm desmids can be confusing until somewhat minor variations in wall shapes and decor are scrutinized. The most common include Docidium, Gonatozygon, Penium, Pleurotaenium, Roya and Triploceras.
Habitat:
Widespread in Sphagnum bogs and somewhat acidic oligotrophic lakes.
References:
Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 22 May 2013. Ralfs, J. 1848. The British Desmidieae. pp. [i]-xxii, [i], [1]-226, pls I-XXXV. London: Reeve, Benham & Reeve.