Figure 3.

Time-calibrated phylogeny of the Basilares clade with representative sampling of major clades of Cactaceae and its outgroup. Stars indicate the three nodes that were constrained based on secondary calibrations from [19] of the stem of Cactaceae, crown of Cactaceae, and crown of Opuntioideae. Posterior distributions of node ages are shown by density plots at each node, centered on the mean age. Numbers at the top of the figure represent millions of years. Most clades of Opuntieae had a Pliocene origin, as did the Basilares clade, which arose in the Mid Pliocene. The Xerocarpa clade had a putative mid-late Pliocene origin. The Basilaris clade also had a late Pliocene origin, although most lineages were derived within the Pleistocene. The Polyacantha clade arose during the early Pleistocene.