title: The evolutionary history of Mimosa (Leguminosae): toward a phylogeny of the sensitive plants.
abstract: OBJECTIVE
  Large genera provide remarkable opportunities to investigate patterns of morphological evolution and historical biogeography in plants. A molecular phylogeny of the species-rich and morphologically and ecologically diverse genus Mimosa was generated to evaluate its infrageneric classification, reconstruct the evolution of a set of morphological characters, and establish the relationships of Old World species to the rest of the genus.
  
  
  METHODS
  We used trnD-trnT plastid sequences for 259 species of Mimosa (ca. 50% of the total) to reconstruct the phylogeny of the genus. Six morphological characters (petiolar nectary, inflorescence type, number of stamens, number of petals, pollen type, and seismonasty) were optimized onto the molecular tree.
  
  
  RESULTS
  Mimosa was recovered as a monophyletic clade nested within the Piptadenia group and includes the former members of Schrankia, corroborating transfer of that genus to Mimosa. Although we found good support for several infrageneric groups, only one section (Mimadenia) was recovered as monophyletic. All but one of the morphological characters analyzed showed high levels of homoplasy. High levels of geographic structure were found, with species from the same area tending to group together in the phylogeny. Old World species of Mimosa form a monophyletic clade deeply nested within New World groups, indicating recent (6-10 Ma) long-distance dispersal.
  
  
  CONCLUSIONS
  Although based on a single plastid region, our results establish a preliminary phylogenetic framework for Mimosa that can be used to infer patterns of morphological evolution and relationships and which provides pointers toward a revised infrageneric classification.
authors: Department of Plant Sciences, University of Oxford, South Parks Rd, Oxford, OX1 3RB, UK. msimon@cenargen.embrapa.br
authors: Marcelo F
authors: MF
authors: Simon
authors: Rosaura
authors: R
authors: Grether
authors: Luciano P
authors: LP
authors: de Queiroz
authors: Tiina E
authors: TE
authors: Särkinen
authors: Valquíria F
authors: VF
authors: Dutra
authors: Colin E
authors: CE
authors: Hughes
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D030541:Databases, Genetic; D005843:Geography; D031298:Mimosa / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics* / Q000502:physiology*; D010802:Phylogeny; D019655:Quantitative Trait, Heritable; D055110:Radiometric Dating
chemical_list: D018744:DNA, Plant