Background and Aims: Huperzia serrata is distributed mainly in Asia, but also occurs in Mexico, where it has previously been recorded only in the states of Hidalgo and Oaxaca. The aim of this study is to report the presence of H. serrata in the state of San Luis Potos & iacute; for the first time, and to update and expand the anatomical and morphological description of the Mexican representatives of this taxon. Methods: Fertile specimens were collected from the states of Hidalgo and San Luis Potos & iacute;. Samples of roots, stems, and leaves were processed using standard anatomical techniques and the anatomical and morphological descriptions were made based on the obtained information. Key results: The anatomical characteristics observed were consistent whit those previously reported for the genus. However, the vascular cylinder of the stem was found to be actinostelic in the basal region and becomes plectostelic toward the apex. In addition, variation in the number of xylem arms was observed across the different regions analyzed, and the presence of prismatic crystals is reported here for the first time. Conclusions: The study contributes to the knowledge of the morphology, anatomy and distribution knowledge of the species in Mexico. Only a few populations are currently known in the country and they occur in areas threatened by deforestation and human population growth. Therefore, additional fieldwork is needed to assess the conservation status of the taxon.
Background and Aims: Hybridization is a common phenomenon in Agave and is considered an important component of the evolution of the genus. Recent botanical explorations in the state of Aguascalientes, Mexico, led to the discovery of populations of an Agave exhibiting morphological characters intermediate between A. angustifolia and A. filifera. The aims of this study are to describe these populations as a new nothospecies, compare it with its putative parental species and morphologically similar taxa, and document its geographic distribution. Methods: Field expeditions conducted in Aguascalientes between 2020 and 2022 resulted in the collection of a new putative hybrid of Agave. Morphological comparisons with the putative parental species and related taxa were conducted. A distribution map was generated from herbarium and field records, and the conservation status was assessed following IUCN criteria. Key results: Agave & times; hidrocalida is described as a new intersubgeneric nothospecies endemic to Aguascalientes, Mexico. Morphological and ecological evidence supports its origin from hybridization between A. angustifolia (subg. Agave) and A. filifera (subg. Littaea). The nothospecies exhibits characters intermediate between its putative parental species, including entire leaf margins and a raceme-like paniculate inflorescence. A preliminary conservation assessment places it in the Vulnerable (VU) category. Conclusions: Agave & times; hidrocalida expands the diversity of known nothospecies in Agave and provides additional evidence of the role of hybridization in the evolution of the genus. The occurrence of multiple, morphologically homogeneous populations across its distribution range warrants further studies to determine whether hybrid speciation has taken place.
Background and Aims: The genus Atrostemma (Apocynaceae) includes 10 climbing plant species of subtribe Gonolobinae, which are distributed from Guatemala to Brazil. This paper describes a new species of Atrostemma for the state of Veracruz, Mexico; this is also the first record of the genus for the country. Methods: The new species was discovered during botanical expeditions in the municipality of Emiliano Zapata, Veracruz, from December 2025 to June 2026. The taxonomic identification was carried out by reviewing specialized literature and consulting type specimens available online. Its conservation status was assessed according to IUCN Red List criteria. Key results: Atrostemma mexicanum sp. nov. is endemic to Veracruz, Mexico, and grows in riparian vegetation similar to subtropical evergreen forest and in transition zones between oak forest and tropical deciduous forest, at elevations above 700 m. It is distinguished from the otherAtrostemma species of Central America (A. glaberrimum, A. hadrostemmum, and A. hammelii) by its shorter calyx lobes, as well as differences in indumentum and the length of the gynostegium stipite. A record on iNaturalist suggests the presence of a second population between the municipalities of C & oacute;rdoba and Orizaba, Veracruz. However, it could not be physically located despite explorations in the area where the record was made. Due to its restricted distribution and highly fragmented habitat, it is proposed that the new species be listed as Critically Endangered (CR). Conclusions: The number of known species in the genus increases to 11 and it is the first species recorded in Mexico, which extends its northern range. This study highlights the importance of continuing botanical and conservation explorations of ecosystems, even when these are already fragmented.
Background and Aims: Climate change and anthropogenic activities pose significant threats to temperate forests, ecosystems where dwarf mistletoes (Arceuthobium) occur. These parasitic plants infect conifers, and their presence has increased because of logging and changes in temperature and precipitation regimes. In this context, the objective of this study was to determine the potential distribution of the genus Arceuthobium in Mexico, identify the abiotic variables that may favor its presence, and assess whether its distribution is expected to increase as a result of climate change. Methods: Species occurrence data for the genus Arceuthobium were obtained from the Global Biodiversity Information Facility (GBIF) database. Bioclimatic variables from WorldClim, along with layers of elevation, enhanced vegetation index (EVI), and evapotranspiration (ETA), were used to generate current and future potential distribution models. Future projections were based on three climate models (HadGEM3-GC31-LL, MRI-ESM2-0 and MIROC6) and two time horizons (2050 y 2080) under two Shared Socioeconomic Pathways scenarios: 4.5 and 8.5. Key results: Model performance, evaluated using the area under the curve (AUC), was >0.9. Five priority areas of potential distribution forArceutho-bium were identified. Future projections indicate that the genus will experience a reduction in its distribution area. Conclusions: The potential distribution of these parasitic plants is expected to decrease, with a tendency to shift toward new refugia in the Trans-Mexican Volcanic Belt and Sierra Madre Occidental. Monitoring and conservation actions are required.
Background and Aims: The genus Scottmoria (Lecythidaceae) has 44 species, distributed from Honduras to Ecuador, which are characterized by having the androecium cap with 3-4 coils, seeds with a white sarcotesta that penetrates into the testa, and an I, J, or inverted L-shaped aril, which can extend sideways. In this work a new species for the genus is formalized. Methods: The herborized material was identified and determined according to the most updated and relevant taxonomic literature for the group. Key results: A new species of Scottmoria is diagnosed and discussed, which becomes the third species of the genus to have an I-shaped aril with lateral expansion, or, rarely, in the shape of a J or inverted L. Conclusion: Scottmoria ovidiana shows a set of characteristics (leaves grouped at the ends of the small branches, blade extending down the petiole, axes of the inflorescence and infructescences ramiflorous, with lenticels, unbranched, 4.5-5 cm long, depressed to globose large fruits, seeds with the aril in the shape of an I with lateral expansion and rarely in the shape of an inverted J or L) that make it quite distinguishable within the genus, and for this reason, it is formally described here as a new species.
