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

Background and Aims: Stenocereus martinezii is a columnar cactus, endemic to Sinaloa, Mexico, listed as subject to special protection (Pr) in the NOM-059-SEMARNAT-2010 and Endangered (EN) in the IUCN Red List, with high conservation priority. The objectives of the study were to define the potential distribution and geographic area of S. martinezii, determine the anthropic activities with the greatest impact on the vulnerability of the habitat, as well as to locate the populations in the greatest danger of disappearing and those currently in recovery process. Methods: Ecological niche modeling was performed to determine the predicted geographic distribution of S. martinezii, using the climate variables and remote sensing of vegetation characteristics (NDVI), and the Maxent algorithm. Vector layers of land use change and vegetation were added to the previously delineated map in order to determine habitat vulnerability. Key results: The geographic distribution of S. martinezii is limited to seven municipalities in the state of Sinaloa, with the populations established in the municipalities of Badiraguato and Concordia as new records. The total area sampled was 8672.38 km²; 29% of the vegetation cover where it is distributed is at risk of disappearing mainly due to rainfed agriculture. Fifty-seven percent is stable and 14% is in the process of recovery. Conclusions: It was determined that the distribution area of S. martinezii is wider compared with previous reports, with two new records in municipalities of Sinaloa. However, one third of the vegetation in which it is distributed is at risk of disappearing, mainly due to anthropogenic activities.

Background and Aims: Purple corn (Zea mays) is a native variety of the Americas, rich in phenolic compounds, mainly anthocyanins, and other functional phytochemicals. In recent years, its consumption and distribution have increased significantly, not only because it serves as a gastronomic symbol in various regions of Mexico, but also due to its biochemical properties and nutritional potential, which have attracted the interest of research groups around the word. This literature review was conducted with the aim of highlighting the characteristics of the functional chemical compounds found in purple corn, focusing mainly on its anthocyanins and antioxidant content. Methods: A bibliometric analysis was conducted using the Scopus database to identify relevant publications related to the terms “Purple corn” and “Anthocyanins.” Metadata were processed using VOSviewer to construct co-occurrence networks of keywords and analyze research trends. Key results: The bibliometric analysis identified 308 key documents published between 1979 and 2024, and allowed the delineation of four main research themes: anthocyanins, antioxidant compounds, nutritional value, and health benefits. Purple corn stood out for its high anthocyanin content (ca. 1430 mg/100 g), particularly glycosylated derivatives of cyanidin, pelargonidin, and peonidin, whose biosynthesis is influenced by environmental factors. The main antioxidant compounds identified were ferulic acid and quercetin derivatives, exhibiting significant antioxidant capacity (ca. 271.33 mg GAE/g). With respect to nutritional composition, purple corn is rich in carbohydrates, proteins, and fiber. Furthermore, several studies have associated its consumption with anti-obesity, anti-inflammatory, antidiabetic, cardioprotective, and anticancer effects, among other benefits. Conclusions: Purple corn is a functional food with significant health benefits, supported by scientific studies emphasizing its antioxidant properties and nutritional quality. The research conducted has highlighted its potential applications in the food and pharmaceutical industries and underscored the importance of continuing to explore its bioactive properties and nutraceutical applications.

Background and Aims: The genus Pisolithus is characterized by its angiocarpic basidiomes, which have a pulverulent gleba composed of peridioles, apical maturation, and echinulated basidiospores. In Mexico, two closely related species have been cited based exclusively on morphology: Pisolithus tinctorius and P. arhizus, associated with Pinus, Quercus, Carya and Eucalyptus. However, it has been pointed out that none of those species form associations with eucalyptus, and P. arhizus is distributed just in Eurasia based on ITS sequences. This study aims to contribute to the taxonomy and phylogeny of the genus Pisolithus in Mexico by characterizing Pisolithus specimens from temperate and arid zones, based on morphology and ITS barcode sequences of fungarium specimens, as well as soil metabarcoding sequences. Methods: Thirty-two specimens from the MEXU herbarium were characterized macro- and microscopically by light and scanning electron microscopy. Specialized literature was used for morphological identification. DNA was extracted with a CTAB 3% protocol. The ITS region was amplified with the ITS5 and ITS4 primer pairs. Phylogenetic analyses included 21 newly generated sequences, metagenomic soil sequences and sequences deposited in NCBI, and were performed using maximum likelihood and Bayesian Inference methods. Key results: We confirmed the presence of P. tinctorius associated with Pinus, Quercus, and Carya illinoinensis. Pisolithus albus, a new record for Mexico, is distinguished by its association with Eucalyptus sp., a whitish exoperidium, ochraceous gleba, and echinulate basidiospores with short, isolated spines up to 1 µm high. Phylogenetic analysis supports the identity of the Mexican collections. Conclusions: Among the Mexican samples analyzed, two well-defined species of Pisolithus were taxonomically identified, P. albus and P. tinctorius. Based on the material considered in this work, we did not find any that corresponded to P. arhizus.

Background and Aims: Mistletoe seeds germinate readily after being removed from the exocarp by seed dispersers. While the consequences of directed bird dispersal from the perspective of mistletoe-bird mutualistic interactions are well-studied, the effects of fruit size variation on seed germination processes have received limited attention. Here we investigated the different phases of seed germination of manually attached seeds of a Psittacanthus mistletoe, from seed attachment to early haustorial formation, to better understand the germination process of the seed unit (embryo and cotyledons). Methods: We collected fully developed ripe fruits from Psittacanthus mayanus (Loranthaceae) mistletoe plants growing on Lysiloma divaricatum (Fabaceae) host trees, measured (length and width of the fruit and length of cupular pedicels), weighed, and then used them in a germination experiment. For this experiment, we manually removed the exocarp from the ripe fruits and placed the squashed seeds on wooden rectangle sticks, securing them with their own viscin. Seeds were monitored daily for 100 days under common environmental conditions. Key results: Psittacanthus mayanus seeds showed a high germination rate, completing the process in just under two weeks on average. Germination was asynchronous among seeds, with considerable variation in the time each seed took to germinate. Among the morphological characteristics evaluated, only fruit width significantly affected the germination process. Specifically, fruit width influenced seed germination probability, the time they took to germinate, and the number of cotyledons they developed. Seeds from wider fruits showed higher germination probability but developed fewer cotyledons. Conclusions: Our findings suggest that fruit width could be an important trait influencing the reproductive success of this mistletoe species.

Background and Aims: Coccoloba sect. Campderia comprises 14 species, which are recognized by the presence of fruits in the form of diclesia. During the review of herbarium specimens for the taxonomic treatment of the genus Coccoloba for the Flora de Veracruz and the Flora Mesoamericana, several specimens with fruits in the form of diclesia, which do not correspond to any of the species of the sect. Campderia so far described, were located. Therefore, in this work eight new species of Coccoloba sect. Campderia are described and illustrated. Methods: Physical and digital specimens from various herbaria were observed, including type specimens. The existing taxonomic literature on the genus Coccoloba was also consulted. The morphological description, illustrations, distribution map, as well as the assessment of the conservation status of each of the new species are presented. A dichotomous key to all species of the sect. Campderia from Mexico and Central America is included. Key results: Coccoloba burgeri, C. carnevalii, C. costaricensis, C. glandulosa, C. rodriguezii, C. ulloae, C. veracrucensis and C. victoriasosae are described and illustrated as new species. Coccoloba burgeri, C. costaricensis, C. glandulosa are endemic to Costa Rica while the rest are endemic to Mexico. Conclusions: The review of herbarium specimens and literature, combined with the description of the new species of Coccoloba sect. Campderia increase its species number to 28, which can be delimited by a set of character states of the leaves, inflorescences and fruits. Flowers are not helpful to delimit the species in the sect. Campderia.

Background and Aims: Begonia ostulensis is an endemic species, restricted to limestone rock ridges in the deciduous tropical forest of the Michoacán coast in Mexico. It is attractive because it has a single orbicular leaf in the center of which the inflorescence develops, and its foliation and reproduction are limited to the rainy season from July to November. The objective was to determine the conservation status of the species based on its population parameters. Methods: An intensive search for individuals of this species was carried out, in an altitudinal gradient of 100 to 1032 m. In July 2022, population size and density, area of ​​occupancy, spatial distribution pattern (through the Morisita Standardized Index), size structure (using histogram and Sturges algorithm), associated with the proportion of reproductive structures produced were obtained; population growth rate (λ) was calculated over two years (July 2022 and July and September 2023). Key results: In July 2022 the population size was 1268 individuals in an occupation area of 363.6 m², with an aggregated spatial distribution pattern. Population structure indicated low recruitment, with a high proportion of reproductive individuals and few juveniles. No evidence of vegetative reproduction was found; the sex ratio in the flowers produced indicated a high availability of pollen. In July 2023, 1693 individuals were recorded, the population increased by 33.52% between July 2022 and July 2023; however, abnormal drought in August and September 2023 decreased the population by 81.4%, negatively affecting leaf and inflorescence persistence. Conclusions: The population and habitat characteristics make B. ostulensis a priority species for conservation. The species should be listed as Threatened in the NOM-059-SEMARNAT-2010 in México and as Vulnerable in the IUCN Red List.

Background and Aims: Pachyphytum is a genus of the Crassulaceae family, endemic to Mexico, where it is primarily distributed in the Bajío region. It comprises 25 species that tend to grow on rocky walls and most of them exhibit micro-endemic distributions. This study aims to describe and illustrate a new species of Guanajuato state, assess its conservation status and present a distribution map. Methods: Live specimens of the new species were collected and analyzed in fresh to prepare the description. Subsequently, they are to be deposited in the herbaria CIIDIR, IBUG and ZON, while others are being maintained in cultivation in the IBUG living collection. Specialized literature was consulted to determine its morphologically closest species. In addition, the conservation status was assessed based on the IUCN Red List criteria. The distribution map was created using herbarium specimen data from the new taxon and related taxa. Key results: Pachyphytum angustiflorum is described as a species new to science, based on a comparative analysis including P. confusum, P. hookeri and P. viscidum, morphologically the most similar taxa. It is assessed as Critically Endangered (CR) due to its restricted distribution. Conclusions: Pachyphytum angustiflorum is endemic to the Barranca del Beato, municipality Tarimoro, Guanajuato, Mexico. The description of this species contributes to the knowledge of the high species richness and endemism of this genus.

Background and Aims: The subtribe Gonolobinae is one of the most diverse subtribes of the family Apocynaceae, and its taxonomic history continues to undergo numerous changes. Within the subtribe, Matelea, the genus in which more than 200 species have been recognized has changed its circumscription the most, as it has been recovered as paraphyletic in phylogenies. This work proposes the recognition of a new genus that includes Matelea congesta. The relationship with phylogenetically related taxa is also discussed. In addition, a taxonomic treatment of the new genus is presented, in which a new species is proposed.Methods: Both live and herbarium specimens were observed, including types. Taxonomic literature related to the taxa treated was consulted, and a revision of the genus was carried out. A distribution map was prepared. The conservation status was evaluated according to IUCN Red List standards.Key results: The genus Mexicania is proposed with two species endemic to Mexico, one of them named as new, M. guerrerensis (Guerrero). The shape of the bracts, the length and pubescence of the corolla, as well as its distribution, are the attributes that allow separation of both species. An identification key, images and descriptions of its species are provided, as well as a comparison with phylogenetically related taxa. Conclusions: Mexicania is a sister genus to Polystemma, and is distinguished by numerous vegetative and reproductive attributes. This taxon increases to five the number of endemic genera of Apocynaceae for Mexico.

Background and Aims: Chamaedorea (Arecaceae) is a Neotropical genus of approximately 110 species, 50 of which are found in Mexico, making it the country with the highest diversity of the genus. Following a recent revision of Mexican herbaria in the framework of a taxonomic treatment for Chamaedorea in Mexico, a new species was identified. This work’s objective is to describe the new species Chamaedorea mazateca. Methods: The taxonomic identification and description were based on a revision of Mexican and foreign herbarium material, specialized bibliography and living material measurements. Field work was conducted in May 2024 to verify the existence and morphology of the new species. The conservation status of the species was determined based on the criteria of the IUCN Red List and the NOM-059-SEMARNAT-2010. Key results: Chamaedorea mazateca is an endemic species of the Mazatec region of Oaxaca and Puebla, native of tropical montane cloud forests. It is similar to Chamaedorea rojasiana in its leaf divided in few leaflets and a notably larger pair of terminal ones. It differs from this species mainly in leaflet shape and inflorescence characteristics. The Critically Endangered (CR) category is provisionally proposed under the IUCN Red List criteria, and the in danger of extinction (P) category for the NOM-059-SEMARNAT-2010. Conclusions: With the description of C. mazateca, the richness of Chamaedorea in Mexico rises to 51 native species, 21 of which are endemic. This finding highlights the need for detailed herbarium revisions and increased field exploration to expand the knowledge of the genus’ richness, endemism and diversification in Mexico.

Background and Aims: The Apocynaceae family shows high diversity and includes toxic, medicinal, and edible species. However, the studies on the safety, toxicity, and nutritional value of its edible species are scarce. The objectives of this study were to evaluate the phytochemicals content, toxicity, antioxidant activity, and proximate composition of the fruits and inflorescences of five Apocynaceae species from northwestern Mexico: Funastrum clausum, F. heterophyllum, F. pannosum, Gonolobus naturalistae y Ruehssia tholiformis.Methods: Phytochemical analyses were carried out to identify families of compounds with toxic potential. Toxicity was evaluated using Artemia salina and mouse models. The results were compared to those from Asclepias curassavica. Total phenolic and flavonoid contents, as well as antioxidant activity (ABTS, DPPH, and ORAC), were evaluated using spectrophotometric methods. Proximate composition was determined using AOAC methodologies, and dietary fiber was analyzed with a commercial kit. Key results: Compared to A. curassavica, the evaluated species lacked potentially toxic phytochemicals (e.g., alkaloids or anthracenes) and were found to be non-toxic in both models. Funastrum clausum fruit and F. pannosum inflorescence showed the highest phenolic content and antioxidant activity, whereas the fruits of R. tholiformis and G. naturalistae had the lowest. The protein (10.74% - 14.71% d.w.), lipid (3.97% - 7.19% d.w.), and dietary fiber (24.15% - 36.78% d.w.) contents were comparable to other vegetables such as broccoli, cucumber, chayote, and Opuntia cladodes. Conclusions: The studied Apocynaceae species were non-toxic, and their consumption could significantly contribute to dietary fiber intake and antioxidant phytochemicals, supporting their traditional use as food.