Late C enozoic diversification of the austral genus L agenophora ( A stereae, A steraceae)

L agenophora ( A stereae, A steraceae) has 14 species in N ew Z ealand, A ustralia, A sia, southern S outh A merica, G ough I sland and T ristan da C unha. Phylogenetic relationships in L agenophora were inferred using nuclear and plastid DNA regions. Reconstruction of spatio‐temporal evolution was estimated using parsimony, B ayesian inference and likelihood methods, a B ayesian relaxed molecular clock and ancestral area and habitat reconstructions. Our results support a narrow taxonomic concept of L agenophora including only a core group of species with one clade diversifying in N ew Z ealand and another in S outh A merica. The split between the N ew Z ealand and S outh A merican L agenophora dates from 11.2 Mya [6.1–17.4 95% highest posterior density ( HPD )]. The inferred ancestral habitats were openings in beech forest and subalpine tussockland. The biogeographical analyses infer a complex ancestral area for L agenophora involving N ew Z ealand and southern S outh A merica. Thus, the estimated divergence times and biogeographical reconstructions provide circumstantial evidence that A ntarctica may have served as a corridor for migration until the expansion of the continental ice during the late C enozoic. The extant distribution of L agenophora reflects a complex history that could also have involved direct long‐distance dispersal across southern oceans. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society , 2015, 177 , 78–95.