XVI International Botanical Congess

Recent discoveries and analyses of freshwater red algal diversity in Australia and New Zealand provide new perspectives on the origins of Australia's intriguing flora. A molecular phylogeny of the Australia-New Zealand endemic genus Psilosiphon shows New South Wales (Australia) to be more closely related to New Zealand than to Tasmania (Australia). This relationship may reflect the history of this region more than 80 million years ago. Most of the other local representatives of the order Batrachospermales are also endemic to Australia or to Australia-New Zealand. Molecular sequencing data supports the establishment of the new taxa based on morphological characters and, further, indicates that some presumed cosmopolitan taxa may have been misinterpreted. The systematics data from freshwater red algae provide a rich source of biogeographic information, possibly demonstrating vicariance events prior to those relevant to flowering plants.