Phylogeny of Gunnera

The phylogeny of the genus Gunnera is investigated for the first time. Twel ve species representing the six currently recognised subgenera are analysed . Two chloroplast DNA regions, the rbcL gene and the rps16 intron, together provide 46 informative characters out of 2335. A combined analysis of both genes gives four most parsimonious trees, firmly establishing the east Sou th American G. herteri as sister group to the rest of the genus. The Africa n G. perpensa is sister group to two well-supported clades, one including t he South American subgenera Misandra and Panke, the other the Australian/Ne w Zealand/Malayan species of subgenera Milligania and Pseudogunnera. Thus, South America is a composite area for Gunnera, showing up at two different levels in the cladogram. Our analysis supports a close biogeographic relati onship between Australia and New Zealand. The evolution of some morphologic al characters is discussed. Lastly, the unusual structure of some of the rb cL sequences is reported.