Una revisión de Acianthera subgénero Brenesia (Orchidaceae, Pleurothallidinae), con una nueva especie de México

Background and Aims: Brenesia was originally proposed to accommodate an odd taxon among the Orchidaceae subtribe Pleurothallidinae. This species is characterized by its sessile leaves, secondary stems covered by inflated sheaths and, especially, by a raceme produced at the base of the secondary stem. A few more closely related taxa were discovered afterwards, but the generic name has mostly been placed under the synonymy of Pleurothallis. Recent DNA-based studies showed that Brenesia constitutes a monophyletic group within the genus Acianthera. We present here a review of Acianthera subgenus Brenesia, delimiting each species in the group and providing a key for their identification. Methods: Specialized literature, specimens deposited in scientific collections, in cultivation, or available at online databases were reviewed. For each species, their known localities were georeferenced and displayed on a map of Mexico and Central America using QGIS software; also, their conservation status was assessed according to the IUCN Red List. Key results: Acianthera subg. Brenesia includes five species distributed from central Veracruz, Mexico, to Panama. The species included in this group are Acianthera costaricensis from Costa Rica and Panama; A. herrerae from Chiapas, in Mexico, and Guatemala; A. johnsonii from Chiapas to Honduras; and A. sotoana from (Mexico) Veracruz and Oaxaca. For each taxon, a morphological description, drawing, photo, information concerning nomenclature, distribution, habitat, phenology, and comparison with similar taxa are provided. Acianthera rzedowskiarum is described as a new species from Chiapas, based on specimens previously confused with A. johnsonii. Conclusions: Acianthera subgenus Brenesia has a distribution restricted to Central America. Four of its five species are native to Mexico, and one is restricted to southern Central America.Antecedentes y Objetivos: Brenesia fue propuesto originalmente para acomodar un extraño taxón en la subtribu Pleurothallidinae de Orchidaceae. Dicha especie se caracteriza por sus hojas sésiles, tallos secundarios cubiertos por vainas infladas y, sobre todo, por un racimo producido en la base del tallo secundario. Luego se descubrieron algunos taxa similares adicionales, pero el nombre genérico por lo general fue incluido bajo la sinonimia de Pleurothallis. Estudios recientes basados en el ADN demostraron que Brenesia constituye un grupo monofilético dentro del género Acianthera. Aquí presentamos una revisión de las especies de Acianthera subgénero Brenesia, delimitando cada especie del grupo y proporcionando una clave para su identificación. Métodos: Se revisó literatura especializada, ejemplares depositados en colecciones científicas, en cultivo o disponibles en bases de datos en línea. Para cada especie sus localidades conocidas fueron georreferenciadas y sobrepuestas en un mapa de México y Centroamérica usando el software QGIS; además, se evaluó su estado de conservación de acuerdo con los Criterios de la Lista Roja de la UICN. Resultados clave: Acianthera subg. Brenesia incluye cinco especies distribuidas desde el centro de Veracruz, México, hasta Panamá. Estas especies son Acianthera costaricensis de Costa Rica y Panamá; A. herrerae de Chiapas, en México, y Guatemala; A. johnsonii de Chiapas a Honduras y A. sotoana de (México) Veracruz y Oaxaca. Para cada taxón se presenta una descripción morfológica, dibujo, foto, información sobre nomenclatura, distribución, hábitat, fenología y una comparación con taxones similares. Acianthera rzedowskiarum se describe como nueva especie basada en especímenes de Chiapas previamente confundidos con A. johnsonii. Conclusiones: Acianthera subgénero Brenesia tiene una distribución restringida a América Central. Cuatro de sus cinco especies son nativas de México y una se restringe al sur de América Central

Recent origin and rapid speciation of Neotropical orchids in the world's richest plant biodiversity hotspot

The Andean mountains of South America are the most species-rich biodiversity hotspot worldwide with c. 15% of the world's plant species, in only 1% of the world's land surface. Orchids are a key element of the Andean flora, and one of the most prominent components of the Neotropical epiphyte diversity, yet very little is known about their origin and diversification. We address this knowledge gap by inferring the biogeographical history and diversification dynamics of the two largest Neotropical orchid groups (Cymbidieae and Pleurothallidinae), using two unparalleled, densely sampled orchid phylogenies (including more than 400 newly generated DNA sequences), comparative phylogenetic methods, geological and biological datasets. We find that the majority of Andean orchid lineages only originated in the last 20–15 million yr. Andean lineages are derived from lowland Amazonian ancestors, with additional contributions from Central America and the Antilles. Species diversification is correlated with Andean orogeny, and multiple migrations and recolonizations across the Andes indicate that mountains do not constrain orchid dispersal over long timescales. Our study sheds new light on the timing and geography of a major Neotropical diversification, and suggests that mountain uplift promotes species diversification across all elevational zones.O.A.P-E. is supported by a Colombian National Science Foundation (COLCIENCIAS) scholarship and G.C. is supported by a German Science Foundation grant (RE 603/20). F.L.C. is supported by a Marie Curie grant (BIOMME project, IOF627684) and has benefited from an ‘Investissements d’Avenir’ grant managed by Agence Nationale de la Recherche (CEBA, ref. ANR-10-LABX-25-01). A.P.K. and D.B. were supported by grants from the Alberta Mennega Foundation. N.J.M. was supported by the National Institute for Mathematical and Biological Synthesis, an Institute sponsored by the National Science Foundation (NSF) through NSF Award no. EFJ0832858, with additional support from The University of Tennessee, Knoxville, and is currently supported by a Discovery Early Career Researcher Award DE150101773, funded by the Australian Research Council, and by The Australian National University. D.S. is funded by the Swedish Research Council (2015-04748). A.A. is supported by grants from the Swedish Research Council, the European Research Council under the European Union’s Seventh Framework Program (FP/2007-2013, ERC Grant Agreement no. 331024), the Swedish Foundation for Strategic Research and a Wallenberg Academy Fellowship

Prosthechea madrensis, a reconsideration of Epidendrum madrense Schltr. (Orchidaceae: Laeliinae)

Volume: 88Start Page: 47End Page: 5

Prosthechea madrensis, una reconsideración del Epidendrum madrense Schltr. (Orchidaceae: Laeliinae)

Epidendrum madrense, traditionally treated under the synonymy of Prosthechea chacaoensis, is recognized as a distinct species and transferred to Prosthechea. The number, length, and shape of the nectar guides on the labellum are useful taxonomic characters to distinguish closely related species in Prosthechea.Epidendrum madrense, tratada tradicionalmente como un sinónimo de Prosthechea chacaoensis, es reconocida como una especie distinta y se transfiere al género Prosthechea. El tamaño, la forma y el número de las guías nectaríferas del labelo son caracteres útiles para distinguir entre especies cercanas en el genero Prosthechea

Lankester Composite Dissection Plate (LCDP) of <i>Specklinia dunstervillei</i> Karremans, Pupulin & Gravendeel.

<p>A. Habit. B. Flower. C. Transverse section of a whole flower. D. Dissected perianth. E. Column and lip, lateral view. F. Petals and lip. G. Column in ventral and lateral view. H. Pollinia and anther cap. Based on photographs of <i>Karremans 5899</i> (JBL) by A.P. Karremans.</p

Acuarela of <i>Specklinia dunstervillei</i> Karremans, Pupulin & Gravendeel.

<p>By Sylvia Strigari, based on <i>Karremans 5899</i> (JBL).</p

<i>Specklinia dunstervillei</i> Karremans, Pupulin & Gravendeel.

<p>Unpublished photographs by G. C. K. Dunsterville from the plant found in Trujillo, Venezuela (<i>Dunsterville 757</i>). A. The plant habit. B. Detail of the flower. Reproduced with the kind permission of the Orchid Herbarium of Oakes Ames, the Harvard University Herbaria.</p

Pairwise comparison of the number of single base differences amongst the nrITS sequences of <i>S</i>. <i>dunstervillei</i>, <i>S</i>. <i>endotrachys</i>, <i>S</i>. <i>montezumae</i>, <i>S</i>. <i>pfavii</i>, <i>S</i>. <i>spectabilis</i> and <i>S</i>. <i>remotiflora</i>.

<p>Pairwise comparison of the number of single base differences amongst the nrITS sequences of <i>S</i>. <i>dunstervillei</i>, <i>S</i>. <i>endotrachys</i>, <i>S</i>. <i>montezumae</i>, <i>S</i>. <i>pfavii</i>, <i>S</i>. <i>spectabilis</i> and <i>S</i>. <i>remotiflora</i>.</p

<i>Specklinia dunstervillei</i> Karremans, Pupulin & Gravendeel

<p>. A) Habit; B) Flower; C) Dissected perianth; D) Lateral view of the lip placement relative to lateral sepals; E) Column and lip, lateral view; F) Column, ventral view; G) Lip, extended; H) Petals; I) Anther cap with pollinia; J) Pollinia. Drawn from the holotype (<i>Karremans 5966</i>) by Esmée Winkel.</p