XVI International Botanical Congess

The biogeography of the red alga Bostrychia has been investigated using both plastid- and mitochondrial-encoded DNA sequence data. In B. moritziana, several distinct lineages have been detected, with one main Australia-South Africa lineage also represented in Japan. Isolates of the B. tenella/B. montagnei complex reveal a complex biogeographic pattern in which long-distance dispersal can explain the phylogeographic relationships. The relationships in the B. calliptera/B. pinnata complex can be interpreted similarly. Results suggest that long-distance dispersal is the major factor responsible for present-day biogeographic relationships in Bostrychia and this is consistant with the observation that isolates from the same locality can have very different phylogenetic histories.