Jackknifing estimated weighted least squares

Statistical Methods

To be, or not to be a Stelis

Despite the availability of multiple sources of evidence and consistency in the support for a broadly circumscribed Stelis Sw. (Orchidaceae: Pleurothallidinae), some authors continue to be hesitant in its use. It is certain that the more typical species of Stelis, with their triangular, flattish flowers with very short fleshy petals and lip, form a monophyletic group that is easily recognized. However, it is likewise undisputed that they are not an isolated lineage in the subtribe and that several groups of species with a similar vegetative habit but lacking the typical Stelis flower are in fact very close relatives, sharing a relatively recent common ancestor. Those species groups need to be classified in a way that also reflects their own evolutionary history; alternatives to a broadly circumscribed Stelis are possible yet neither straightforward or practical at this time. An infrageneric classification for the whole group is provided here in an attempt to clarify which species belong where in this highly complex affinity. Emphasis is made on the difficulty of diagnosing the less typical members of each proposed subgenus or section, and on the importance of floral convergence and divergence as a result of pollinator adaptation. As here defined, Stelis is the largest genus in the Pleurothallidinae, with 1243 species.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL

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

Back to caring after being hurt: The role of forgiveness

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