Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Background and Aims: Although the phycological knowledge for the Mexican Pacific region is broad, most studies have been oriented to know the flora adhered to rocky substrates. However, the number of works on macroalgae that grow on living organisms, such as epizoics, is limited. The purpose of this paper is to contribute to the knowledge of epizoic algal flora in the Mexican tropical Pacific.Methods: Four samplings of the mollusk Chiton articulatus were carried out in two locations in Guerrero, Mexico, during 2014, to know the algae that grow on it. Furthermore, a literature review of studies in the Mexican tropical Pacific was carried out to obtain the records of the algae that grow on animals. Finally, algae on molluscs were determined by observations of complete thallus and sections.Key results: A total of 124 species, 81 genera, 51 families and 27 orders was reported, distributed in four algae divisions. The orders with the highest specific richness were Ceramiales (23) and Corallinales (20), and the families with the highest number of species were Rhodomelaceae (13), Cladophoraceae (11) and Lithophyllaceae (10). The most diverse genera were Amphiroa and Cladophora (7). For Guerrero, 12 new species records are presented, of which three are also new records for the Mexican tropical Pacific and three for the Mexican Pacific. The state with the highest number of recorded species was Guerrero (58). The most common substrate was mollusks. The predominant algal morphofunctional group were the filaments.Conclusions: The results of this work demonstrate that the biodiversity of algae present on animal substrates is high, contributing significantly to the specific richness recorded for Guerrero and the Mexican Pacific. The importance of developing more studies that focus on knowledge of algal epibiosis is evident.

Background and Aims: Quantitative methods have accumulated for the use of linear measurements and Cartesian coordinates of landmark points in analyses of morphometric variation. Unlike previous reviews, here I emphasize the theoretical bases of mathematical spaces and morphospace of a taxonomic character. The goal of this contribution is to provide conceptual elements for a basic understanding of morphometric and statistical methods useful in systematics under a phylogenetic approach.Methods: Morphometric data are being applied in comparative biology research, using a phylogeny as a reference. In contrast, applications of morphometrics in systematics have been with the aim of phenetic grouping and distinguishing taxonomic groups with overall similarity. Under a phylogenetic approach, morphometric data can also be used for the study of taxonomic character variation, character state identity and phylogenetic inference. Taxonomic groups should be proposed from monophyletic groups discovered with phylogenetic methods.Key results: I review the basic morphometric theory, vector geometry, Kendall shape space, Procrustes distance, projection of tangential spaces, and construction of morphospace hypercubes. Remainders of statistical concepts useful for the application of Principal Component Analysis and Canonical Variate Analysis in systematics are presented. Particularly, I give examples and recommendations on the use of linear measurements and landmark coordinates in morphometric analyses for the identification of species, the variation of taxonomic characters and in the inference of phylogeny and classification.Conclusions: The current broad collection of methods provides an opportunity to integrate morphometric data to discover taxic and transformational homology. This implies an epistemological change necessary to move from applications in systematics under a phenetic approach to the integration of morphometric analyses as part of phylogenetic research.

Antecedentes y Objetivos: Wurdastom es un género neotropical poco conocido y pobremente representado en colecciones de herbario. Se realizó una síntesis histórica, discusión de su posición tribal, revisión taxonómica y un análisis del estado de conservación de las especies del género. Métodos: Se revisaron ejemplares de Wurdastom de 17 herbarios en Colombia (CAUP, COAH, COL, CUVC, FMB, HUQ, PSO, UDBC, UPTC, VALLE), Ecuador (QCA, QCNE) y Estados Unidos de América (CAS, F, MO, NY, US) y se consultaron los ejemplares tipo disponibles en JSTOR Global Plants. Se elaboró una clave de identificación, así como descripciones, ilustraciones y mapas de distribución de cada una de las especies. Se emplearon las pautas y los criterios de la UICN para las evaluaciones de conservación de todas las especies del género.Resultados clave: En total, se encontraron 52 colecciones de Wurdastom en los herbarios revisados. Se describe una especie nueva de Colombia y se documentan isotipos no conocidos con anterioridad procedentes del herbario VALLE. Wurdastom es un género pequeño de árboles y arbustos distribuidos desde el centro-occidente de Colombia hasta el norte de Perú, en bosques andinos y húmedos de zonas bajas. El género forma parte de la tribu Cyphostyleae y se caracteriza por la venación acródroma de las hojas, presencia de tricomas barbelados en las estructuras vegetativas e inflorescencia, inflorescencias multifloras tirsoides o pleiotirsoides, flores haplostemonas, pétalos ≤1 cm de largo, ovario ínfero y frutos capsulares. Conclusiones: Wurdastom comprende ocho especies neotropicales, la mayoría de distribución restringida. Se evalúa una especie como Amenazada (W. sneidernii), dos como Vulnerable (W. cuatrecasasii, W. dudleyi) y el resto puede ubicarse en la categoría de Datos Insuficientes.

Background and Aims: The savannas of the Yucatán Peninsula have been studied in the last decade to know their plant diversity, structure and phytogeographical patterns of its plant components. Among the extant savannas in the south of Yucatán, one locally named Chacho Lugo has been scenario of extensive field work and its flora is well known. Recent expeditions to the site have documented new records of monocots and ferns for the Yucatán savannas. The objective of this study is to present the novelties that the site adds to the peninsular flora. Methods: During 2016 to 2019, expeditions were made to the savanna Chacho Lugo, botanical specimens were collected and deposited in the UADY herbarium. The specimens were identified using specialized literature and by comparison with herbarium material and high-resolution scanned specimens available on electronic pages. Key results: Following the identification of the specimens and the review of their distribution, Ophioglossum nudicaule and Paspalum serpentinum are registered for the first time for the savannas of the Yucatán Peninsula. Conclusions: These reports increment the diversity of Pteridophytes to 17 families, 34 genera and 67 species, and to 24 species of Paspalum in the Yucatán peninsula.

Background and Aims: The genus Unguiculariopsis of the class Leotimycetes within Ascomycota is characterized by forming inconspicuous apothecia up to 2 mm in diameter, with hook-shaped hairs on the external surface, inoperculate and inamyloid asci, and globose, subglobose to ellipsoid ascospores, which are hyaline with guttules. They are fungicolous fungi which are host-specific. The objective of this study is to report Unguiculariopsis ravenelii for the first time in Mexico.Methods: The specimens studied are deposited in the ENCB herbarium of the Instituto Politécnico Nacional, Mexico. The material was reviewed in fresh and dry, and described macromorphologically using a stereomicroscope, based on pictures taken in situ, and micromorphological characters with an optical microscope. They were identified with specialized keys and literature.Key results: The description of Unguiculariopsis ravenelii of Mexico is presented. This is a species characterized by being mycoparasite and forming gregarious apothecia growing on Rhytidhysteron rufulum.Conclusions: This species is distributed in tropical dry forest and produces its sporomas during the rainy season in the states of Colima, Jalisco, Nayarit, Oaxaca, Puebla, Sonora, Tabasco and Tamaulipas in the Neotropical region of Mexico.

Background and Aims: Govenia purpusii is a species of the Orchidaceae family; it has a restricted distribution within subalpine forests of the states of Chiapas, Colima, Durango, Guerrero, Hidalgo, Jalisco, Mexico, Michoacán, Oaxaca, Puebla, Querétaro, Veracruz and Zacatecas. The aim of this study was to describe the discovery of this species in La Malinche National Park, Tlaxcala to include it in the floristic inventory.Methods: A population of G. purpusii was identified in the field and collections were made. Through the comparison of botanical material collected with herbarium specimens, the species was determined considering vegetative and floral characters for its identification.Key results: The species was found in Quercus-Pinus vegetation at 2780 m altitude, sharing space with Selaginella sp., Oxalis sp., Peperomia sp. and Pinguicula moranensis.Conclusions: Monitoring this population is recommended due to the small distribution area in La Malinche National Park and the limited knowledge of this population, local extinction would represent a loss of genetic material for the species. This record should not be interpreted as a recent extension in its range, the presence within this area may be the result of forest fragmentation in the Trans-Mexican Volcanic Belt.

Background and Aims: In Mexico, the Neotropical genera of Annonaceae tribe Miliuseae, including Sapranthus, Stenanona and the Mexican endemic genus Tridimeris, are particularly diverse and many of their species are endemic to this country. This diversity is not fully documented and many new species have been discovered as a result of recent botanical explorations in southern Mexico. Here, we describe a new species of Stenanona. Methods: We collected a new species of Stenanona during field work in a little known karst forest area located in the highlands of Chiapas, Mexico. The new species was recognized using the unique combination of features through comparisons with morphologically similar species and literature review. We assessed its conservation status by calculating its extent of occurrence (EOO) and its area of occupancy (AOO) using the GeoCAT tool and applying the IUCN Red List Categories and criteria. Key results: A new species of Annonaceae, namely Stenanona morenoi, endemic to karstic forests of southern Mexico, is described and illustrated.  According to the criteria established by the IUCN, it is possible to tentatively determine the species as Critically Endangered (CR B1ab (iii)). Conclusions: Based on its general floral morphology, S. morenoi is hypothesized to belong to subclade A of the Desmopsis-Stenanona clade. Within this lineage, S. morenoi shares several morphological features with S. migueliana, S. stenopetala and S. zoque.

Antecedentes y Objetivos: En el sureste de México los estudios florísticos, y en particular los que tratan sobre las Hylocereeae, son escasos. Se pre­senta un estudio florístico taxonómico de las Cactaceae en Tabasco para conocer la riqueza y distribución de sus especies, se generó un listado de especies nativas y cultivadas y se presenta una clave de identificación de las especies para Tabasco. Métodos: Se consultaron los herbarios CSAT, MEXU, UJAT y XAL, así como literatura taxonómica pertinente para tener una aproximación de la diver­sidad de Cactaceae en Tabasco. Se realizó trabajo de campo en todos los tipos de vegetación del estado para obtener las muestras necesarias; éstas se depositaron en el herbario UJAT. Con el material colectado y los ejemplares revisados en los herbarios, se realizaron claves de identificación para los géneros y especies registrados. Resultados clave: En Tabasco se registran siete géneros y 14 especies de cactáceas, seis de las cuales representan nuevos registros para el estado. El género Selenicereus es el más diverso, mientras que el bosque tropical perennifolio y el municipio Tacotalpa presentaron la mayor riqueza de espe­cies. Conclusiones: Las cactáceas en Tabasco se encuentran pobremente representadas en comparación con los estados del centro-norte de México; sin embargo, con los estados de Campeche y Yucatán se observa una notoria similitud en cuanto a la riqueza de especies.

Antecedentes y Objetivos: Las cianobacterias son algas procariontes oxifotótrofas presentes en gran variedad de hábitats y son componentes importantes de las comunidades bentónicas en muchos ambientes continentales y marinos. En México su diversidad en ríos es poco conocida; por ello, este estudio contribuye al conocimiento ficoflorístico en cinco ríos de la región central de México. Se incluyen descripciones e ilustraciones, estimaciones de su diversidad, un análisis de las relaciones entre formas de crecimiento y factores microambientales, y se discute la validez de su caracterización morfológica y ecológica en la delimitación de las especies encontradas. Métodos: Se realizaron muestreos en secas y lluvias en dos ríos silíceos y tres ríos calcáreos del centro de México. Se registró la temperatura del agua, conductividad específica y pH, se analizaron iones mayores (Ca2+, Mg2+, K+, Na+, Si-SiO2, HCO3-, Cl-, SO43-) y nutrientes (NH4+, NO2-, NO32-, PO43-), se estimó la diversidad de las cianobacterias registradas con el índice de Shannon-Weaver y se describieron sus hábitats y microhábitats. La identificación taxonómica se realizó utilizando literatura especializada. Resultados clave: Se identificaron cuatro asociaciones y nueve especies pertenecientes a tres órdenes, siete familias y siete géneros. Se distinguieron dos grupos: el formado por Nostoc parmelioides-Coleodesmium wrangelii y Phormidium lividum-Leptolyngbya truncata en ríos silíceos de montaña y el compuesto por Schizothrix mexicana-Phormidium subfuscum, Homoeothrix juliana-Heteroleibleinia fontana y Nostoc verrucosum en ríos calcáreos cálidos. Se reconocieron dos patrones de distribución ecológica: 1) las especies del orden Nostocales presentes en condiciones estresantes de luz y velocidad de corriente y 2) los taxa de los órdenes Oscillatoriales y Synechococcales registrados en sitios con valores promedio de luz y flujo de agua. Conclusiones: La caracterización morfológica y ecológica de especies de cianobacterias contribuye a su conocimiento ficoflorístico y es la base para futuras investigaciones sobre taxonomía, sistemática y uso sustentable de recursos algales.

Background and Aims: Since the contributions of Dreckmann in 1998, and Ortega et al. in 2001, there are no other integrative studies for the Mexican Atlantic seaweeds in which modifications and taxonomic actualizations were considered for this regional phycological flora. Hence, our main objective was to present an update for the marine benthic red algae from the Mexican coast of the Gulf of Mexico, and the Mexican Caribbean Sea, in which all the new records are included for the region since the contributions mentioned above. Materials and Methods: The information about the species was obtained through the analysis of all the specialized literature published for the region since 2001, as well as some previous records not considered before, and a revision of the databases of the UAMIZ Metropolitan Herbarium. Synonymy and nomenclatural status, as well as the classification system used, were revised in AlgaeBase. Key results: A checklist composed of 451 species and 13 infraespecific categories of red algae was obtained; these where distributed in 4 classes, 23 orders, 52 families, and 171 genera. The currently accepted name, synonymy, and distribution are mentioned for each species. An asterisk indicates previous records (prior to 2002), as well as its distribution in different habitats. Conclusions: The present contribution revealed two main changes to the previously known flora of the red algae from the study area. The first one falls in the domain of nomenclature, and implies a modification in their classification (families, genera, and species). The second one has an effect on the number of species present. As a consequence, it is evident that constant floristic monitoring is required along the coasts of the Mexican Atlantic.