Fig. 6

(a and b) Divergence time estimations for Saxifragaceae with focus on Saxifraga sect. Saxifraga (arrow) using an uncorrelated lognormal relaxed clock model applied for Sanger and NGS nrITS2 sequence data with the software BEAST v. 1.8.4. The numbers 1 to 17 refer to the main clades characterised in Table 1. Node heights indicate median ages. Horizontal node bars show the 95% posterior density probability date ranges. Four calibration points (see main text) are marked by circles. The time line with the main geological epochs is shown as horizontal axis in million years. Labelling behind taxon names as in Fig. 5