Posterior age distribution of the three fossil-calibrated internal nodes in the orchid phylogeny (outlined in Figure 2). The diagrams show the age of the most recent common ancestor of these nodes (in millions of years) plotted against frequency of trees, from the combined results of 5 independent BEAST runs of 20 million generations each (burn-in excluded). (A) Crown age of tribe Goodyerinae, constrained to a minimal age of 15 Ma. (B) Crown age of genus Dendrobium, constrained to a minimal age of 20 Ma. (C) Crown age of genera Earina and Agrostophyllum (in this analysis, equivalent to stem age of Earina), constrained to a minimal age of 20 Ma.