title: Phylogeny, systematics, and trait evolution of Carex section Glareosae.
abstract: •
  
  
  OBJECTIVE
  The circumboreal Carex section Glareosae comprises 20-25 currently accepted species. High variability in geographic distribution, ecology, cytogenetics, and morphology has led to historical problems both in species delimitation and in circumscribing the limits of the section, which is one of the major tasks facing caricologists today.•
  
  
  METHODS
  We performed phylogenetic reconstructions based on ETS, ITS, G3PDH, and matK DNA sequences from 204 samples. Concatenation of gene regions in a supermatrix approach to phylogenetic reconstruction was compared to coalescent-based species-tree estimation. Ancestral state reconstructions were performed for eight morphological characters to evaluate correspondence between phylogeny and traits used in traditional classification within the section.•
  
  
  RESULTS
  The results confirm the existence of a core Glareosae comprising 23-25 species. Most species constitute exclusive lineages, and relationships among species are highly resolved with both the supermatrix and coalescent-based species-tree approaches. We used ancestral state reconstruction to investigate sources of homoplasy underlying traditional taxonomy and species circumscription. We found that even species apparently not constituting exclusive lineages are morphologically homogeneous, raising the question of whether paraphyly of species is a phylogenetic artifact in our study or evidence of widespread homoplasy in characters used to define species.•
  
  
  CONCLUSIONS
  This study demonstrates the monophyly of Carex section Glareosae and establishes a phylogenetic framework for the section. Homoplasy makes many of morphological characters difficult to apply for taxon delimitation. The strong concordance between supermatrix and species-tree approaches to phylogenetic reconstructions suggests that even in the face of incongruence among molecular markers, section-level or species-level phylogenies in Carex are tractable.
authors.affiliation: Pablo de Olavide University, ctra. de Utrera, km 1, Ed. 22 41013, Seville, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Maguilla
authors.affiliation: Department of Integrative Ecology, Estación Biológica de Doñana (EBD-CSIC), Avda. Americo Vespucio s/n 41092, Seville, Spain Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Apartado 1095 41080, Sevilla, Spain.
authors.forename: Marcial
authors.initials: M
authors.lastname: Escudero
authors.affiliation: McGill University, Plant Science, Macdonald Campus 21111 Lakeshore, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada.
authors.forename: Marcia J
authors.initials: MJ
authors.lastname: Waterway
authors.affiliation: The Morton Arboretum, 4100 Illinois Route 53, Lisle, Illinois 60532 USA Botany Department, Field Museum of Natural History, Chicago, Illinois 60605 USA.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Hipp
authors.affiliation: Pablo de Olavide University, ctra. de Utrera, km 1, Ed. 22 41013, Seville, Spain.
authors.forename: Modesto
authors.initials: M
authors.lastname: Luceño
mesh_terms: D005075:Biological Evolution; D031255:Carex Plant / Q000145:classification / Q000235:genetics*; D002965:Classification; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000145:classification / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics; D013045:Species Specificity
chemical_list: D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer; D010940:Plant Proteins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases
keywords: Ancestral state reconstruction; ETS; G3PDH; ITS; lineage sorting; matK; species tree; supermatrix