LA FLORA DEL MUNICIPIO DE ATENANGO DEL RÍO, ESTADO DE GUERRERO, MÉXICO Á

A floristic study of the municipality ofAtenango del Río, in the State of Guerrero,Mexico, is presented. Botanical collectionsmade over a period of a year, supplementedby a literature search and herbarium work,resulted in the identification of 643 speciesand 349 genera in 95 families. The familieswith the most species are Leguminosae (96species), Compositae (75), Euphorbiaceae(42), and Gramineae (29). The studydenotes the presence 49 species endemic tothe Balsas River Basin that are present inAtenango del Río.Se presenta la riqueza florística del municipio Atenango del Río en el estado de Guerrero, México. Para ello se elaboró la listade las especies de plantas vasculares conbase en la colecta realizada durante un añoen todo el municipio, así como en la revisión de material de herbario y de literatura.Los resultados muestran una cifra de 643especies, distribuidas en 349 géneros y en95 familias para el municipio. Las familiasmejor representadas, a nivel de especie, enla zona son: Leguminosae con 96 especies,Compositae con 75, Euphorbiaceae con 42 yGraminae tiene 29. Destaca la presencia de49 especies que restringen su distribución ala cuenca del Balsas y que están presentesen Atenango del Río

El género Mitreola (Loganiaceae) en México

Background and Aims: Loganiaceae is a group of tropical plants, which have been poorly studied in Mexico. Some of the taxa are little known in terms of their taxonomy and distribution, such as the genus Mitreola, where additionally some of the species have nomenclatural problems. This work focuses on a taxonomic review of Mitreola petiolata and solves the nomenclatural problems that the species has had over the years.Methods: A review of specimens in different herbaria was carried out, specialized literature to obtain descriptions and taxonomic keys, the number of species of the genus and their distribution, as well as the circumscription and nomenclatural problems of the taxon. To obtain the palynological data, material from mature flowers was acetylated and revised with the scanning electron microscope. From these data an evaluation of the conservation situation was obtained.Key results: Mitreola petiolata has a pantropical distribution and is the only species of the genus present in the country, growing from Tamaulipas and Sinaloa to the Yucatán Peninsula. In spite of the morphological variation of structures such as the leaves or the lobes of the capsule, the characters of taxonomic importance (dichotomic inflorescence, subsessile flowers and stamens inserted close to the base of the corolla) remain constant.A review for M. petiolata, a dichotomous key, data on its distribution and conservation status in the country is provided. Detailed information on the micromorphology of pollen grains is presented, the first made for the species. The category of Least Concern is suggested, due to its wide distribution.Conclusions: The constant revision and curation of biological collections, keeps knowledge of taxa updated. This is the case of Mitreola petiolata, for which an update of its systematics, distribution and state of conservation is provided.Antecedentes y Objetivos: Loganiaceae es un grupo de plantas tropicales que se han estudiado escasamente en México. Algunos de sus taxones son poco conocidos en cuanto a su taxonomía y distribución, como el caso del género Mitreola, en el que además algunas de sus especies tienen problemas nomenclaturales. Este trabajo presenta una revisión taxonómica de Mitreola petiolata y resuelve los problemas nomenclaturales que ha tenido a lo largo de los años.Métodos: Se revisaron especímenes en diferentes herbarios, literatura especializada para la obtención de descripciones y claves taxonómicas, número de especies del género y su distribución; así como la circunscripción y problemas nomenclaturales del taxon. Para la obtención de los datos palinológicos, se acetolizó material de flores maduras y se revisó en el microscopio electrónico de barrido. A partir de los datos obtenidos se obtuvo una evaluación de la situación de conservación.Resultados clave: Mitreola petiolata tiene una distribución pantropical y es la única especie del género presente en el país. La especie se extiende desde Tamaulipas y Sinaloa hasta la Península de Yucatán. A pesar de la variación morfológica de estructuras como las hojas o los lóbulos de la cápsula, los caracteres de importancia taxonómica (inflorescencias dicotómicas, flores subsésiles y estambres insertos cerca de la base de la corola) se mantienen constantes. Se proporciona una revisión para M. petiolata, una clave dicotómica, datos sobre su distribución y estado de conservación en el país. Se presenta información detallada sobre la micromorfología de los granos de polen, la primera hecha para la especie. Se sugiere la categoría de preocupación menor por su amplia distribución.Conclusiones: La constante revisión y curación de las colecciones biológicas mantiene actualizado el conocimiento de los taxones. Tal es el caso de M. petiolata, para la cual se proporciona una actualización de su sistemática, distribución y estado de conservación

Data from: Complex phylogeographic patterns indicate Central American origin of two widespread Mesoamerican Quercus (Fagaceae) species

The northern Neotropical region is characterized by a heterogeneous geological and climatic history. Recent studies have shown contrasting patterns regarding the role of geographic elements as barriers that could have determined phylogeographic structure in various species. Recently, the phylogeography and biogeography of Quercus species have been studied intensively, and the patterns observed so far suggest contrasting evolutionary histories for Neotropical species in comparison with their Holarctic relatives. The goal of this study was to describe the phylogeographic structure of two Neotropical oak species (Quercus insignis and Quercus sapotifolia) in the context of the geological and palaeoclimatic history of the northern Neotropics. Populations through the distribution range of both species were collected and characterized using nine chloroplast DNA microsatellite loci. Both oak species showed high levels of genetic diversity and strong phylogeographic structure. The distribution of genetic variation in Q. insignis suggested an influence of two major barriers, the Isthmus of Tehuantepec and the Nicaraguan Depression, while Q. sapotifolia exhibited a genetic structure defined by the heterogeneity of the Chortis highlands. The haplotype networks of both species indicated complex histories, suggesting that colonization from the Sierra Madre de Chiapas to central Mexico and from the north of the Nicaraguan Depression to the Costa Rican mountains may have occurred during different stages, and apparently more than one time. In conclusion, the phylogeographic structure of Neotropical oak species seems to be defined by a combination of geological and climatic events

Complex phylogeographic patterns indicate Central American origin of two widespread Mesoamerican Quercus (Fagaceae) species

The northern Neotropical region is characterized by a heterogeneous geological and climatic history. Recent studies have shown contrasting patterns regarding the role of geographic elements as barriers that could have determined phylogeographic structure in various species. Recently, the phylogeography and biogeography of Quercus species have been studied intensively, and the patterns observed so far suggest contrasting evolutionary histories for Neotropical species in comparison with their Holarctic relatives. The goal of this study was to describe the phylogeographic structure of two Neotropical oak species (Quercus insignis and Quercus sapotifolia) in the context of the geological and palaeoclimatic history of the northern Neotropics. Populations through the distribution range of both species were collected and characterized using nine chloroplast DNA microsatellite loci. Both oak species showed high levels of genetic diversity and strong phylogeographic structure. The distribution of genetic variation in Q. insignis suggested an influence of two major barriers, the Isthmus of Tehuantepec and the Nicaraguan Depression, while Q. sapotifolia exhibited a genetic structure defined by the heterogeneity of the Chortis highlands. The haplotype networks of both species indicated complex histories, suggesting that colonization from the Sierra Madre de Chiapas to central Mexico and from the north of the Nicaraguan Depression to the Costa Rican mountains may have occurred during different stages, and apparently more than one time. In conclusion, the phylogeographic structure of Neotropical oak species seems to be defined by a combination of geological and climatic events.Programa de Becas Posdoctorales DGAPA, UNAMRed Latinoamericana de Botánica-Andrew W. Mellon Foundation GrantPAPIIT IV201015CONACYT 240136 grantsUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Habitabilidad y política de vivienda

En esta obra, en la que participan destacados investigadores y profesores, dedicados al estudio de la problemática habitacional se presentan diferentes análisis que permiten conocer cuales son las condiciones de habitabilidad y las características de la actual política de vivienda de México. En sus capítulos se abordan los principales desafíos que enfrentan las familias mexicanas para acceder a una vivienda digna y decorosa y cuales son los retos económicos, políticos, territoriales, arquitectónicos, ambientales, financieros y culturales de las formas de producción habitacional en México y en otros países, en el marco de una sociedad global