XVI International Botanical Congess
Aristolochiaceae comprises about 600 species, mostly in tropical and warm temperate regions. Inferred from trnT-trnF sequences, this study provides the first molecular phylogeny for Aristolochiaceae. To examine outgroup effects, representatives of Piperales (Lactoridaceae, Piperaceae, Saururaceae) and of other basal angiosperms (e.g., Austrobaileya, Ceratophyllum) were used. Within monophyletic Aristolochiaceae all analyses revealed two major lineages. These are equivalent to Asaroideae (Saruma, Asarum s.l.) and Aristolochioideae (remaining 7 genera). Within the aristolochioids, Pararistolochia, which is not commonly recognized as a distinct genus, forms a well resolved clade. Representative species of Isotrema from Asia and America appear monophyletic.