Figure 1.

Chronogram based on BEAST analyses using fossil calibration. The scale shows ages in million years. The 95% highest posterior density bars are indicated for the nodes of interest, labelled as follows: (a) the Gentiana fossil, (b) the Lisianthius fossil, (c) the Emmenopterys fossil, (d) crown node of Ixanthus, (e) and (f) nodes corresponding, respectively, to the potential vicariance events due to the separation of the Madagascar–India block from Africa and later of India from Madagascar. Coloured letters above selected branches indicate ancestral areas (see the electronic supplementary material) and numbers above the branches are posterior probabilities derived from the Bayesian inferences analysis. (Online version in colour.)