Marcgraviaceae is a distinctive neotropical family with approximately 130 species distributed from the Caribbean and southern Mexico to northern Bolivia. Phylogenetic analysis of rbcL sequence data strongly supports the monophyly of the family. NdhF, trnL-F, and rbcL sequence comparisons resolve two major lineages within Marcgraviaceae corresponding to subfamilies Marcgravioideae and Noranteoideae. The monogeneric Marcgravioideae is united by both morphological synapomorphies and molecular data. In contrast, subfamily Noranteoideae appears to be delimited by plesiomorphic morphological characters but is supported as monophyletic by molecular data. Our data suggest a close relationship between representative species of Schwartzia and Ruyschia, which share a unique 47 base pair insertion in the trnL-F spacer but have not been allied in morphological classifications. Despite considerable morphological differences among taxa of Noranteoideae, our sequence data do not resolve some currently recognized genera as monophyletic groups.

Communicating Editor: Kathleen A. Kron