title: Pollinators underestimated: a molecular phylogeny reveals widespread floral convergence in oil-secreting orchids (sub-tribe Coryciinae) of the Cape of South Africa.
abstract: The oil-secreting orchids of southern Africa belong to the sub-tribe Coryciinae within Diseae. A phylogeny of Diseae is inferred using sequence data from all genera in the tribe, with an emphasis on resolving generic classifications within Coryciinae. Nuclear (ITS) and plastid (trnLF and matK) gene region sequences were analysed for 79 ingroup taxa and three outgroup taxa. Coryciinae is confirmed to be diphyletic, with Disperis and Coryciinae sensu stricto (s.s.) forming separate monophyletic clades. The current genera Corycium and Pterygodium are not monophyletic according to our analysis and we propose a subdivision of Coryciinae s.s. into 10 monophyletic clades including three monotypic groups. Previous generic classifications of Coryciinae s.s. have been hampered by convergent evolution of floral parts, a consequence of few pollinator species and limited pollinia attachment sites in the oil-bee pollination system common to this group.
authors.affiliation: Division of Biology, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK. R.Waterman04@Imperial.ac.uk
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Waterman
authors.forename: Anton
authors.initials: A
authors.lastname: Pauw
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Barraclough
authors.forename: Vincent
authors.initials: V
authors.lastname: Savolainen
mesh_terms: D018744:DNA, Plant / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D019143:Evolution, Molecular; D035264:Flowers / Q000145:classification / Q000235:genetics; D008957:Models, Genetic; D029595:Orchidaceae / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D018087:Plastids / Q000235:genetics; D054817:Pollination; D017422:Sequence Analysis, DNA; D013019:South Africa
chemical_list: D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer