New Gomphonema (Bacillariophyta) species from Tasmania

Eleven new species of the diatom genus Gomphonema are described from brown-water habitats in Tasmania, Australia. These species are endemic to individual habitats or suites of systems, and most are known only from Tasmania. Although many of the Tasmanian species are morphologically similar to others from that island, those that are astigmate appear to be related to other astigmate taxa found in the Southern Hemisphere. Thus, we can recognize restricted distributions of diatom species at different geographic scales, from individual water bodies to hemispheres.