AimOrchidaceae is the most species-rich angiosperm family and has one of the broadest distributions. Until now, the lack of a well-resolved phylogeny has prevented analyses of orchid historical biogeography. In this study, we use such a phylogeny to estimate the geographical spread of orchids, evaluate the importance of different regions in their diversification and assess the role of long-distance dispersal (LDD) in generating orchid diversity. LocationGlobal. MethodsAnalyses use a phylogeny including species representing all five orchid subfamilies and almost all tribes and subtribes, calibrated against 17 angiosperm fossils. We estimated historical biogeography and assessed the importance of different regions for rates of speciation, extinction and net species diversification. We evaluated the impact of particular LDD events on orchid diversity by asking how many species evolved in the new range subsequent to those events. ResultsOrchids appear to have arisen in Australia 112Ma (95% higher probability distribution: 102.0-120.0Ma), then spread to the Neotropics via Antarctica by 90Ma (HPD: 79.7-99.5Ma), when all three continents were in close contact and apostasioids split from the ancestor of all other orchids. Ancestors of vanilloids, cypripedioids and orchidoids+epidendroids appear to have originated in the Neotropics 84-64Ma. Repeated long- and short-distance dispersal occurred through orchid history: stochastic mapping identified a mean total of 74 LDD events or 0.8Ma(-1). Across orchid history, Southeast Asia was the most important source and maximally accelerated net diversification; across epidendroids, the Neotropics maximally accelerated diversification. Main conclusionsOur analysis provides the first biogeographical history of the orchids, implicating Australia, the Neotropics and Antarctica in their origin. LDD and life in the Neotropics - especially the Andes - had profound effects on their spread and diversification; >97% of all orchid species are restricted to individual continents

Three new species of Porroglossum from Ecuador are described and illustrated. Porroglossum miguelangelii is compared to the Peruvian P. lycinum, from which it differs by the longer, narrower petals with margins that are not obtusely angled below the middle and the presence of stigmatic tooth-like processes. Porroglossum merinoi is distinctive in that it is the only species with densely pubescent sepals. Porroglossum porphyreum is similar to P. schramii, but differs in the sepals with a thickened tail abruptly inserted at their apex, the petals with teeth on both the upper and lower margin, and the labellum provided with a longer and broader basal callus.

New species of Masdevallia, Pleurothallis, Stelis, Trisetella and Zootrophion are described and illustrated, including three new forms of Masdevallia and one new form of Pleurothallis. New synonymy is provided for Acianthera dodsonii, Stelis pachyglossa, S. retusa, S. transversalis and Zootrophion serpentinum.

A new species, superficially similar to Pleurothallis allenii, and best attributed to Pleurothallis sect. Pleurothallis subsect. Acroniae ser. Amphygiae, is described here as Pleurothallis flavomarginata. The new species was discovered under cultivation at the orchid nursery Ecuagenera. The new species is described, illustrated, and distinguished from similar species based on its morphological distinctness.

A new species of Specklinia with a repent growth habit and minute purple flowers is described and illustrated. The new species is distinguished from Specklinia wrightii based on its morphological and molecular distinctness from that species. The phylogenetic placement of the new species is provided based on an nrITS tree. The species described here represents the first new orchid to be described from material originating from the Parc National Naturel Macaya in six years. New combinations are made in Acianthera for species of Kraenzlinella and Pleurothallis subgen. Antilla embedded within the genus. In particular Kraenzlinella rinkei is provided as a new synonym for Specklinia montezumae and Specklinia simpliciflora is transferred to Acianthera sect. Antilla based on morphology and geographic distribution.