Annals of Botany 110: 71–90, 2012 doi:10.1093/aob/mcs083, available online at www.aob.oxfordjournals.org Phylogenetics of tribe Orchideae (Orchidaceae: Orchidoideae) based on combined DNA matrices: inferences regarding timing of diversification and evolution of pollination syndromes Luis A. Inda1,*, Manuel Pimentel2 and Mark W. Chase3 1Escuela Polite´cnica Superior de Huesca, Universidad de Zaragoza, carretera de Cuarte sn. 22071 Huesca, Spain, 2Facultade de Ciencias, Universidade da Corun˜a, Campus da Zapateira sn. 15071 A Corun˜a, Spain and 3Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK * For correspondence. E-mail
[email protected] Received: 3 November 2011 Returned for revision: 9 December 2011 Accepted: 1 March 2012 Published electronically: 25 April 2012 † Background and aims Tribe Orchideae (Orchidaceae: Orchidoideae) comprises around 62 mostly terrestrial genera, which are well represented in the Northern Temperate Zone and less frequently in tropical areas of both the Old and New Worlds. Phylogenetic relationships within this tribe have been studied previously using only nuclear ribosomal DNA (nuclear ribosomal internal transcribed spacer, nrITS). However, different parts of the phylogenetic tree in these analyses were weakly supported, and integrating information from different plant genomes is clearly necessary in orchids, where reticulate evolution events are putatively common. The aims of this study were to: (1) obtain a well-supported and dated phylogenetic hypothesis for tribe Orchideae, (ii) assess appropriateness of recent nomenclatural changes in this tribe in the last decade, (3) detect possible examples of reticulate evolution and (4) analyse in a temporal context evolutionary trends for subtribe Orchidinae with special emphasis on pollination systems.