The circumscription of the Old World Passiflora subgenus Decaloba supersection Disemma has been problematic for more than one hundred years. Supersection Disemma consists of 22 Old World species found throughout mainland Asia, Southeast Asia, Australia, and the Pacific. They show great morphological diversity, possessing cup-shaped to tubular flowers and both branched and unbranched inflorescences. These features have been used to link species in Disemma to New World members of subgenus Decaloba, resulting in the widespread suspicion that Disemma is not monophyletic. Plastid (trnL-F intron and spacer) and nuclear (ITS) DNA sequences were used to test the monophyly of supersection Disemma and reconstruct phylogenetic relationships within this group. Two monotypic genera, Hollrungia and Tetrapathaea, were included in this analysis based on their strong morphological similarity to Passiflora, and the Austral-Pacific distribution they share with many of the Old World species. Supersection Disemma is monophyletic, containing two distinct Asian and Australian lineages. Hollrungia and Tetrapathaea are strongly supported as members of Passiflora, though their exact relationships to each other are not resolved. The tubular floral morphology in the Australian species is not homologous with that in the New World species. However, the tubular morphology of P. hollrungii from Papua New Guinea is homologous to the New World tubular condition. The architecture of inflorescences in Disemma is more similar to that in closely related species of Passiflora than to other genera of Passifloraceae.