title: Several origins of floral oil in the Angelonieae, a southern hemisphere disjunct clade of Plantaginaceae.
abstract: •
  
  
  OBJECTIVE
  Over the past 75 Myr, successive groups of plants have entered the "oil bee pollination niche," meaning that they depend on oil-collecting bees for their pollination. The highly dissimilar numbers of plant species and bee species involved in these mutualisms imply evolutionary host switching, asymmetric mutual dependencies, and uncoupled diversification. Among the clades with the best field data on oil bee behavior is the Angelonieae, which we here investigate to better understand the evolutionary time frame of this pollination syndrome.•
  
  
  METHODS
  We generated nuclear and plastid data matrices for 56% of the Angelonieae species (plus outgroups) and used Bayesian methods of molecular clock dating, ancestral state reconstruction, and biogeographic inference.•
  
  
  RESULTS
  We found that Angelonieae have two major clades, Angelonia (including Monopera) and Basistemon, and Monttea, Melosperma, and Ourisia.•
  
  
  CONCLUSIONS
  Angelonieae date back to the Uppermost Eocene, ca. 35 (26-47) Myr ago (Ma) and diversified in dry areas of southern South America; they switched from nectar to oil as a reward four or five times over the past 25 Ma. As predicted in a previous non-clock-dated study, dispersal to Australasia dates to the Miocene/Pliocene.
authors.affiliation: Systematic Botany and Mycology, University of Munich (LMU), Menzinger Str. 67, 80638 Munich, Germany Department of Zoology, Federal University of Paraná, PB 19020, 81531-980 Curitiba, Paraná, Brazil.
authors.forename: Aline C
authors.initials: AC
authors.lastname: Martins
authors.affiliation: Systematic Botany and Mycology, University of Munich (LMU), Menzinger Str. 67, 80638 Munich, Germany.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Scherz
authors.affiliation: Systematic Botany and Mycology, University of Munich (LMU), Menzinger Str. 67, 80638 Munich, Germany.
authors.forename: Susanne S
authors.initials: SS
authors.lastname: Renner
mesh_terms: D000818:Animals; D044362:Australasia; D001499:Bayes Theorem; D001516:Bees; D019143:Evolution, Molecular; D035264:Flowers / Q000378:metabolism*; D019684:Magnoliopsida / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D063148:Plant Dispersal; D010938:Plant Oils; D054817:Pollination; D013020:South America
chemical_list: D010938:Plant Oils
keywords: Plantaginaceae; molecular clock; oil-offering flowers; parallel evolution; southern hemisphere disjunction