New or otherwise interesting desmid taxa from the Bangweulu region (Zambia). 2. Genera Staurodesmus, Staurastrum and Xanthidium (Desmidiales)

Abstract

Background and aims – In a second contribution to the desmid flora of the Bangweulu wetlands in Zambia a selection of species from the genera Xanthidium, Staurodesmus and Staurastrum is discussed for their taxonomy and geographical distribution.Material and methods – Samples were collected from Lake Bangweulu and adjacent swamps as well as from Lake WakaWaka. Collection was by squeezing submerged plant material or using a plankton net.Key results – Four taxa are described as new to science: Staurodesmus bangweuluensis, Std. coutei, Std. thomassonii and Staurastrum onychophorum. Three taxa are recombined: Staurastrum zahlbruckneri var. africanum to S. bidentulum var. africanum, Staurastrum unicorne to Staurodesmus unicornis and Arthrodesmus curvatus to Staurodesmus curvatus. Xanthidium decoratum var. longispinum is raised to species level whereas two taxa, Staurodesmus subunguiferus var. longiradiatus and Std. longiradiatus var. granulatus were provided with new names: Staurastrum zambiense and S. zambiense var. granulatum, respectively.Conclusions – Almost all taxa discussed may be considered African endemics underlining the specific character of the African desmid flora. Many identifications in older desmid literature from Africa, especially infraspecific taxa assigned to species originally described from Europe, appear to need a critical revision.