Fig. 2

Chronogram and biogeographic reconstructions of Bulbophyllum. BEAST-derived species-level maximum clade credibility (MCC) chronogram of Bulbophyllum (plus outgroups) based on ITS sequence data, with branch lengths proportional to time reflecting the established relationships of the four regional lineages (see also Pridgeon et al. [42]). Median node ages (in millions of years ago, Ma) and their 95% highest posterior density (HPD) intervals are indicated at nodes of interest (see also Additional file 1: Figure S1). White circles at nodes indicate Bayesian posterior probabilities (PP) [see also Additional file 1: Figure S2 for all numerical PP values]. Pie charts above and below nodes of interest show the relative probabilities of each possible range configuration as obtained from BAYESTRAITS and BIOGEOBEARS (DEC model), respectively. The insert map shows the geographical distribution of the four regional lineages (colour coded), with the key identifying extant and possible ancestral ranges. Note that each terminal branch represents a single extant species