Eolimna archibaldii spec. nov. and Navigiolum adamantiforme comb. nov. (Bacillariophyceae): two possibly endemic elements of the South African diatom flora tolerant to surface water pollution

Abstract

Two little-known diatom taxa have been encountered in the saprobic and anthropogenically impacted waters of the Vaal River, South Africa. Eolimna archibaldii, an extremely small-celled species, is described as new to science. Navicula adamantiformis Archibald is transferred to the taxonomically-appropriate genus Navigiolum Lange-Bertalot, Cavacini, Tagliaventi and Alfinto, as no specific characters of N. adamantiformis coincide with Navicula sensu stricto.