Perforate Desmodesmus and Scenedesmus (Chlorophyceae) with special reference to Argentinean species
This paper deals with the taxonomy and the geographical distribution of perforated Desmodesmus (R. Chod.) An, Friedl et Hegewald and Scenedesmus Meyen in Argentina. Entire coenobia are mainly represented in these genera, but both genera encompass a small group of perforated forms. Perforations may be linear (Desmodesmus perforatus (Lemm.) Hegewald var. perforatus, D. perforatus var. iberaënsis (Tell) Hegewald, D. tropicus (Crow) Hegewald var. tropicus, D. tropicus var. longiclathratus (Tell) Hegewald et Jeon, Scenedesmus ellipticus var. clathratus (Biswas) Hegewald), or isodiametric (S. arcuatus (Lemm.) Lemm. var. arcuatus, S. arcuatus var. platydiscus G. M. Smith, S. obtusus Meyen, S. verrucosus Roll). In South America, and particularly in Argentina, the taxonomy of these two genera presents uncertainties and an erroneous understanding of their geographical distribution. A detailed examination of the descriptions and illustrations of the Argentinean records, together with the observation of new materials, allow to clarify the taxonomy of perforated Desmodesmus and Scenedesmus and to update their geographical distribution in this large country.