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

Background and Aims: Grasslands are the main vegetation in drylands; however, in many cases they are degraded due to a combination of natural and anthropogenic factors. One strategy to restore these lands is the planting of native annual or perennial forage species that are tolerant to high temperatures, high levels of sunshine, water deficit, and capable of growing in poor or saline soils. The objective of this study was to explore the effect of abiotic factors on the germination performance of three key grass species from arid zones: Leptochloa crinita, Pappophorum caespitosum and Digitaria californica.Methods: The germination percentage (G) and mean germination time (MGT) were evaluated under light and darkness conditions, in the presence and absence of spikelets, and at five constant temperatures (15, 20, 25, 30 and 35 °C). In a germination chamber, 25 spikelets or naked caryopses were sown in sterile Petri dishes with neutral germination paper, irrigated with distilled water, and arranged randomly. The germination count (visible radicle) was carried out every 24 hours for 5 days.Key results: Light had a positive effect on the germination of L. crinita and P. caespitosum. The germination of D. californica decreased considerably at 15 and 35 °C. The spikelet was the factor with the greatest negative effect on the germination of all three species. The triple interaction of the factors indicated that the three species have a better germination performance in light, with temperatures between 20 and 25 °C and in the absence of spikelets.Conclusions: The three species could be used in soil restoration programs in degraded arid zones, mainly due to their plasticity to germinate at different temperatures and with light incidence. Naked caryopses increase germination percentage and improve MGT.

Background and Aims: The first records of benthic marine algae for the Veracruz coast date back to 1846; after 114 years, Mexican phycologists restarted their study. There are 312 species recorded for this area. Considering this species richness, as well as the taxonomic modifications and updates that these groups have had, the aim of this work was to present a list of the identified seaweeds organized by taxonomic categories and with data on distribution, temporality and new records for the study area. Methods: Ninety-two samplings were carried out over a period of 18 years, at the intertidal level in 11 localities on the Veracruz coast. Previous records from 1960 to 2020 were also obtained through a bibliographic revision and the phycological collection of the ENCB herbarium was reviewed as well. The nomenclatural status of each species and the classification system were reviewed. The α diversity for each locality was calculated with the Shannon-Wiener index; a clustering analysis was also performed using UPGMA with the PAST v. program. Key results: The phycofloristic list includes 316 species of benthic marine algae distributed in 3 Phyla, 6 classes, 31 orders, 60 families and 130 genera. Each species includes distribution on the Veracruz coast, reproduction, seasonality, habitat, observations, bibliography and ENCB herbarium catalog number. The α diversity analyzes show that the greatest diversity is in localities with predominantly rocky substrate with 180 species. The summer rains recorded a high number of species (269); Barra de Cazones has the highest number with 181 species, 70 new records were found for the Veracruz coast; with this the number of taxa increased to 391. Conclusions: The list reveals a higher specific richness of marine algae compared to that reported in Yucatán, Campeche, and Tabasco. The phytogeographic affinity of the algae of the Veracruz coast is mixed, since tropical and Caribbean taxa converge there. Constant monitoring is necessary to determine changes in the algal community to establish conservation and use programs.

Background and Aims: The largest diversity of the genus Vanilla shows a preference for humid and flooded areas such as palm-swamp peat forests, which limits the collection and quality of specimens. This study focuses on the vegetative propagation of Vanilla pompona subsp. grandiflora in flood-prone areas of the Alto Mayo Valley, Peru. The objective is to determine the optimal number of nodes for the healthy growth of cuttings, using low-cost substrates. Methods: The research was conducted in the nursery of Finca Don Pepito in Tingana, department of San Martín, Peru. A fully randomized experimental design was employed, considering four types of cuttings and four substrates (treatments). Observations were made throughout the experiment, assessing bud activation, the health of the cuttings, and their relationship between the treatments. Key results: The results indicate that bud activation is significantly influenced by the number of nodes in the cuttings, showing greater efficiency as the number of nodes increases. Conclusions: Propagation through two-node cuttings is considered the best alternative due to the limited availability of genetic material. Furthermore, the health of the cuttings is more closely related to the type of cutting rather than to the substrate treatments.

Background and Aims: Cercocarpus (Dryadoideae, Rosaceae) is an endemic genus to the central-western United States of America and Mexico. Three taxonomic revisions recognize six to 21 species, which have been delimited mainly based on morphological foliar characters and are grouped into the complexes C. ledifolius, C. betuloides, C. montanus and C. fothergilloides. The Cercocarpus fothergilloides complex includes four taxa endemic to Mexico, but present morphological variation and more species could be recognized. The aims of this work were to identify and delimit the species of the fothergilloides complex, establish if the characters correlate with latitude and longitude as well as describe the anatomy and leaf architecture.Methods: We quantified 13 foliar and floral morphological characters and eight anatomical ones of the leaf. We used two Canonical Discriminant Analyzes (CDAs) to examine the quantitative morpho-anatomical data. With the most important quantitative characters from the CDA and ten qualitative morpho-anatomical and leaf architecture ones, we performed a clustering analysis to recognize groups. A correlation analysis between characters and latitude and longitude was performed.Key results: The number of secondary veins, the length of the lamina, the fruit pedicel, the style and the fruit were the morphological characters that allowed differentiating species. Anatomical characteristics such as the thickness of the leaf and cuticle, the height of the palisade parenchyma and epidermis, as well as the depth of the crypt distinguished the taxa. The cluster analysis differentiated seven species. There was not a correlation between most characters with latitude and longitude.Conclusions: The Cercocarpus fothergilloides complex comprises seven species and three of these are new. The species are distinguished by combinations of morphological, anatomical and leaf architecture characters.

Background and Aims: Some species of Pleurotus form anamorphs that produce coremia and arthrospores, which are classified in the subgenus Coremiopleurotus and are morphologically very similar. In Mexico, seven species of the genus are known; however, only P. smithii, described from Mexico City, is known to form coremia. Recent collections of Pleurotus from Chihuahua, Mexico, showed distinct characteristics from the known species for the country, whose morphological and molecular characterization allowed us to identify P. cystidiosus in Mexico. The objective of this work was to document the presence of P. cystidiosus in Mexico and provide a detailed description of the specimens found in the country. Methods: The material was collected in Ciudad Juárez, Chihuahua, Mexico. Specimens were characterized macro- and microscopically through in situ photographs, polyfocal, and light microscopy. Morphological identification was performed using specialized literature. DNA extraction was carried out following a 3% CTAB protocol. The ITS region was amplified using the primer pairs ITS5/ITS4. Phylogenetic analyses were conducted using Maximum Likelihood and Bayesian Inference. Key results: Pleurotus cystidiosus, a species previously unreported in Mexico, is morphologically and taxonomically described, confirmed with barcode sequences. The species is distinguished by the presence of abundant clavate to pyriform pleurocystidia and subglobose cheilocystidia in the teleomorph, as well as the formation of coremia with a white stipe, black head, and segments of arthrospores up to 17-25 × 5-7.5 µm in the anamorph. Conclusions: The presence of P. cystidiosus in the north of Mexico is confirmed. With this study, the number of known Pleurotus species for Mexico increases to eight.

Background and Aims: Bernoullia flammea is a tree species native to the Neotropics for which the germination capacity of the seeds has not been assessed nor the morphology of its seedlings has been described. To fill this information gap, in this work the germination of seeds under light conditions with different storage times and germination in darkness were evaluated. In addition, the macroscopic morphology of the seedling was described. Methods: The fruits were collected in Costa Rica and stored at room temperature (ca. 24 ºC). The germination capacity of the seeds was evaluated through two experiments: (i) effect of storage time on germination and (ii) effect of the absence of light on germination. The seedlings obtained were described based on specialized literature from the emergence of the radicle until three months of age. Key results: The initial germination percentage was higher in seeds with eight months of storage than in seeds with two months, but there were no differences in the final percentage of germination, mean germination time nor in the germination rate between both groups. There were also no differences in the final germination percentage of the seeds that germinated in darkness compared to those that germinated in light conditions. Germination is epigeal and phanerocotylar. The seedlings have opposite, cordate, and photosynthetic cotyledons, alternate eophylls of variable morphology, deciduous stipules, and absence of indumentum. Conclusions: The seeds of B. flammea are quiescent, maintain viability for at least eight months, do not require light to germinate, and seedlings can be differentiated from other bombacoids based on the morphology of the eophylls.

Background and Aims: The subtribe Gonolobinae is one of the most diverse in the family Apocynaceae and its taxonomic history continues to undergo numerous changes. Matelea is one of the genera within the subtribe that has undergone the most changes and numerous taxa have been segregated, including the monotypic Microstelma. This paper aims to present an updated treatment of Microstelma and the description of two new species, as well as an identification key, images and descriptions of its species. Methods: Field trips were made and herbarium specimens including types were observed. Taxonomic literature on the taxa treated was consulted, a revision of the genus was made, species plates and distribution maps were prepared, and their conservation status was evaluated. Key results: Three species are recognized for Microstelma, all endemic to Mexico, two named as new species: M. jimenezii (Michoacán) and M. tenorioi (Guerrero and Oaxaca). The length of the pedicels, the morphology and the reticulation pattern of the corolla, as well as the morphology of the gynostegium and its distribution, allowed to recognize the species. Conclusions: Microstelma now has three species and is, together with Thoreauea, one of the most diverse endemic genera of Apocynaceae of Mexico. It is important to continue with the revision work for a better understanding of the morphology and systematics of these groups.

Background and Aims: Coastal dune vegetation houses highly specialized plants that are capable of surviving adversities such as strong winds, salinity, high temperatures, scarcity of fresh water, burial, soil instability, and anthropogenic activities. Coastal dunes ecosystems are considered one the most dynamic systems on Earth. Their communities occur in Mexico on both the Gulf and Pacific sides. The coastal dunes vegetation of the Pacific slope are the least studied. The goals of this study were to describe, analyze and classify the coastal dune vegetation communities along the coast of the state of Jalisco, through the analysis of their composition, structure, flora, and zoning, from a geobotanical point of view with a conservation and management perspective. Methods: The phytosociological methodology of the Zürich-Montpellier sigmatist school was followed to carry out 90 inventories on 36 different beaches. The data obtained in the inventories were analyzed through partition analysis, clustering and non-metric multidimensional scaling methods.Key results: The total number of taxa recognized in the set of inventories was 83. The classification analyzes allowed us to recognize four groups linked to each of the dune fronts: 1) embryonic, 2) primary or frontal, 3) secondary and 4) tertiary or fossil dune.Conclusions: Each type of dune presents particular characteristics, both structural and floristic, that support its classification and zoning from a geobotanical, ecological, and edaphic point of view with a conservation and planning perspective.

Background and Aims: The genus Coutaportla is distributed from northern Mexico to Guatemala and Honduras. It is characterized by tetramerous or pentamerous flowers and loculicidal-dehiscent capsules. Its circumscription has been a matter of debate since the genus Lorencea was segregated. However, molecular studies and morphological characteristics do not support this separation, and therefore the genus includes five species. The objective of this work is to present an updated treatment of Coutaportla, including recently described new species, identification keys, distribution maps by species, and taxonomic descriptions.Methods: A bibliographic review of taxonomic studies and protologues of Coutaportla was conducted. Herbarium specimens, including types, were examined, and online collections and specialized internet portals were consulted to update taxonomic information and generate distribution maps.Key results: Coutaportla includes five species, all of them found in Mexico, with four being endemic and one also distributed in Central America. Three of these are only known from the type locality within the country. Additionally, information about vegetation types where the species develop is presented, ranging from arid, temperate to tropical-humid. Morphologically, species recognition is based on ovary placentation (subapical, median, or basal), floral and leaf characteristics.Conclusions: The comprehensive morphological study of the Coutaportla genus supports the synonymy of Lorencea. Furthermore, it highlights morphological differences and provides analyses of conservation status in which the importance of the genus as a subendemic element for Mexico with a restricted distribution of most of its species is highlighted.

Background and Aims: Cordyceps s.l. is a group of morphologically, phylogenetically and ecologically diverse fungal species, parasites of insects and arachnids. Worldwide more than 1000 species are known and in Mexico 48 have been recorded, most of them from the west, center and south of the country. Particularly in the state of Morelos 13 species have been recorded. The aim of the present study is to update the knowledge on the species of Cordyceps s.l. arthropod pathogen fungi from the state of Morelos and to expand the records for the Mexican mycobiota.Methods: A herbarium revision was made and arthropod pathogenic fungi of Cordyceps s.l. were collected in 14 locations from the state of Morelos, Mexico. The specimens were characterized macro-and microscopically and identification was carried out through specialized literature. The material studied was deposited in the collection of Entomopathogenic Fungi of the Centro de Investigaciones Biológicas of the Universidad Autónoma del Estado de Morelos. Key results: The genus Samsoniella corresponds to a new record for the country with the species S. haniana and the teleomorph of Beauveria pseudobassiana and Blackwellomyces cardinalis is recorded for the first time for Mexico. New records for the state of Morelos are Cordyceps mexicana and Ophiocordyceps humbertii. The families represented in the entity are Cordycipitaceae with the greatest diversity and distribution with five genera and nine species, Ophiocordycipitaceae with three genera and six species and Clavicipitaceae with one genus and three species. Most of the specimens were found as parasites of larvae and adults of lepidopterans and coleopterans.Conclusions: To contribute to the knowledge of Cordyceps s.l. in the state of Morelos five species are recorded and make a total of 18 so far, being the entity with the highest number of records and the catalogue of this group of species for Mexico increases to 49.