As a result of ongoing studies in Caesalpinia sensu lato, new combinations and synonyms are proposed in the reinstated segregate genus Coulteria.

Antecedentes y Objetivos: En México, el género Coulteria es morfológicamente muy diverso y muchas de sus especies son endémicas del país. A pesar de la diversidad, la delimitación entre las especies existentes y su circunscripción no está completamente documentada. Exploraciones en el centro del país durante los últimos 25 años han resultado en la descripción de nuevos taxa de leguminosas dentro de la Depresión del Río Balsas. En este artículo se describe una especie nueva de Coulteria de la porción Oeste de la Depresión del Río Balsas.Métodos: Durante el trabajo de campo, la revisión morfológica, así como los estudios de microscopía electrónica de las especies ya descritas en Coulteria, se detectó una especie nueva para la región de Infiernillo en los estados de Guerrero y Michoacán, México. Para la nueva especie, estimamos su estado de conservación basado en extensión de ocurrencia (EOO) y área de ocupación (AOO), empleando el programa GeoCAT, aplicando las categorías y criterios de la Lista Roja de la IUCN.Resultados clave: Se describe e ilustra a Coulteria delgadoana, una especie nueva de Caesalpinioideae endémica del bosque estacional seco de Guerrero y Michoacán (Oeste de la Depresión del Río Balsas), México, basándose en evidencia morfológica. Coulteria delgadoana posee inflorescencias masculinas de más de 15 cm de longitud, flores pequeñas, hojas con folíolos glabros, venación reticulada prominente, y legumbre glabra castaña con tintes violáceos. Basándonos en los criterios establecidos por la UICN, de manera tentativa proponemos que la especie está En Peligro (EN).Conclusiones: Las características morfológicas de la nueva especie C. delgadoana, sugieren una cercana relación a C. glabra, una especie de Colima y Jalisco. El gran tamaño de la inflorescencia masculina no había sido observado en otras especies de Coulteria. Coulteria delgadoana comparte área de distribución con C. lewisii en Infiernillo.

Abstract— A new species of the genus Coulteria from the seasonally dry forest of the Rio Balsas Depression, Mexico is described and illustrated. Coulteria sousae is morphologically most similar to Coulteria pringlei but differs from it by having smaller flowers (1 cm long), long stipitate fruit, leaflets that are glabrous and coriaceous at maturity, and an allopatric distribution. The conservation status of this species is suggested to be Endangered (EN), according to the IUCN Red List Categories and Criteria.

The pantropical genus Dalbergia includes more than 250 species. Phylogenetic studies of the group are scarce and have only included two or three species distributed in Mexico. We obtained herbarium samples of Mexican, Central American, and South American species (sourced from MEXU). In addition, sequences of GenBank accessions were used to complement the study. Using internal transcribed spacer (ITS), the matK and rbcL sequences from 384 accessions comprising species from America, Asia, and Africa were sampled to evaluate phylogenetic relationships of Mexican species and infrageneric classifications based on morphological data. Phylogenetic analyses suggest that the genus Dalbergia is monophyletic and originated in South America. The species distributed in Mexico are not a monophyletic clade but are divided into four clades with affinities to South American and Asian species clades. There is no correlation between geography and large-scale phylogeny. The estimated ages of the Mexican and Central American clades ranged from 11.32 Ma (Dalbergia granadillo clade) to 1.88 Ma (Dalbergia ecastaphyllum clade). Multiple long-distance dispersal events should be used to explain the current genus distribution.

Spiders are significant predators in terrestrial habitats, with the highest diversity found in tropical ecosystems, but it is also where they are studied least. In this study, we analyzed the effect of seasonality and three environmental variables (precipitation, evaporation, and temperature) in the orb-weaver composition, richness, abundance, dominance, and diversity. In addition, the species turnover between three localities with differences in the vegetation composition and maintenance in the Sierra de Huautla, Morelos, Mexico, were evaluated. The collection methods used included beating vegetation and direct searches conducted over seven hours during daylight, once per month, between April 2013 and March 2014. A total of 17 species from 14 genera were registered. With the records, we compiled the first species inventory of araneids for the three localities, adding eight new species records for the state of Morelos. The predominant species were Neoscona oaxacensis (Keyserling, 1864) and Trichonephila clavipes (Linnaeus, 1767), but over 50% of the species that we recorded corresponded to a single individual. The Araneid community changed between the dry and rainy seasons in all three localities, with each locality responding differently to changes in environmental variables, with most variables maintaining a long-term effect on the spider community.