• Premise: Bromeliaceae form a large, ecologically diverse family of angiosperms native to the New World. We use a bromeliad phylogeny based on eight plastid regions to analyze relationships within the family, test a new, eight‐subfamily classification, infer the chronology of bromeliad evolution and invasion of different regions, and provide the basis for future analyses of trait evolution and rates of diversification.• Methods: We employed maximum‐parsimony, maximum‐likelihood, and Bayesian approaches to analyze 9341 aligned bases for four outgroups and 90 bromeliad species representing 46 of 58 described genera. We calibrate the resulting phylogeny against time using penalized likelihood applied to a monocot‐wide tree based on plastid ndhF sequences and use it to analyze patterns of geographic spread using parsimony, Bayesian inference, and the program S‐DIVA.• Results: Bromeliad subfamilies are related to each other as follows: (Brocchinioideae, (Lindmanioideae, (Tillandsioideae, (Hechtioideae, (Navioideae, (Pitcairnioideae, (Puyoideae, Bromelioideae))))))). Bromeliads arose in the Guayana Shield ca. 100 million years ago (Ma), spread centrifugally in the New World beginning ca. 16–13 Ma, and dispersed to West Africa ca. 9.3 Ma. Modern lineages began to diverge from each other roughly 19 Ma.• Conclusions: Nearly two‐thirds of extant bromeliads belong to two large radiations: the core tillandsioids, originating in the Andes ca. 14.2 Ma, and the Brazilian Shield bromelioids, originating in the Serro do Mar and adjacent regions ca. 9.1 Ma.
1 May 2012 in Molecular Phylogenetics and Evolution
The phylogenetic relationships of Croton section Cyclostigma sensu Webster were examined using nuclear ribosomal ITS and plastid spacer trnL–F sequences from 48 of the 63 species in the group, including members of the four recognized subsections and representing the group's full morphological and geographic range. The two gene phylogenies concurred that section Cyclostigma sensu Webster is polyphyletic, with its members appearing in nine different clades throughout Croton. The clade that retains the taxonomic type of the section and about half of the species sampled is redefined here as a reduced, monophyletic section Cyclostigma, and the remaining species are placed in other sections or informal clades. The ITS and chloroplast phylogenies are discordant regarding the position of the redefined section Cyclostigma suggesting that reticulate evolution might have played a role in the evolutionary history of this group. These results highlight that the tree habit has evolved on multiple occasions in Croton, and that there are other morphological characters that can effectively distinguish different tree lineages in the genus.