Molecular phylogenetics of Thymelaeaceae with particular reference to African and Australian genera

Phylogenetic relationships of the African and Australian Thymelaeaceae were investigated by parsimony analysis of 41 rbcL nucleotide sequences, including 27 genera and several outgroup taxa. In a second analysis, plastid trnL intron and trnL-F intergenic spacer sequences for the same taxa were included as well. The results from the separate analyses produced highly congruent, although not identical, results. Lastly we combined both sequence regions in one analysis to improve resolution and support. Thymelaeaceae are monophyletic with Thymelaeoideae, Aquilarioideae, Gonystyloideae and Gilgiodaphnoideae clearly recognised. Gonystylus and Lethedon are grouped together, contrary to previous studies that placed Lethedon in Aquilarioideae. The molecular evidence does not support monophyly of the largely African genus Gnidia; at least four major lineages could be identified. Pimelea (Australian) is embedded within one of these lineages, and the others are more closely related to Drapetes (New Zealand and South America), Struthiola, Passerina and Lachnaea (all African).