REVISION OF THE TYPE MATERIALS OF STAURONEIS SCHINZII VAR. ARGENTINA FRENGUELLI AND S. SCHINZII VAR. MAXIMA FRENGUELLI (BACILLARIOPHYCEAE)

Stauroneis schinzii var. argentina and S. schinzii var. maxima were first described from Esteros del Ibera, a large subtropical wetland located in northeast Argentina. The type materials of these varieties were examined with light and scanning electron microscopy and compared to S. schinzii var. schinzii and other infraspecific taxa. As a result of this study the taxonomic validity of both varieties was confirmed, their diagnosis were emended based on the new morphological information derived, and lectotypes and isolectotypes were designated.