Hans von Türckheim

ABSTRACTAimFerns are globally distributed, yet the number of studies examining the historical evolution of African taxa is relatively low. Investigation of the evolution of African fern diversity is critical in order to understand patterns and processes that have global relevance (e.g., the pantropical diversity disparity [PDD] pattern). This study aims to examine when and from where a globally distributed fern lineage arrived in sub‐Saharan Africa, to obtain a better understanding of potential processes contributing to patterns of diversity across the region.LocationGlobal, sub‐Saharan Africa.TaxonAsplenium (Aspleniaceae).MethodsWe analysed five loci from 537 Asplenium taxa using a maximum likelihood (IQ‐Tree) phylogenetic framework. For age estimation, we performed penalised likelihood as implemented in treePL, and executed a Bayesian analysis using BEAST. Biogeographical analyses were carried out using BioGeoBEARS.ResultsMost dispersals into Africa occurred within the last ~55 myr, with the highest diversity of sub‐Saharan African taxa concentrated in two clades, each of which descended from an Asian ancestor. Additional dispersals to sub‐Saharan Africa can be found throughout the phylogeny. Lastly, potential cryptic species diversity exists within Asplenium as evidenced by several polyphyletic taxa.Main ConclusionsWe recover multiple dispersals of Asplenium to sub‐Saharan Africa, with two major lineages likely diversifying after arrival.

Centella asiatica is a medicinal plant recognized for its various benefits contributed by its metabolites and has been used as a food supplement since prehistorical times across various cultures. Due to the reliance on natural populations of C. asiatica and the impacts of environmental factors on its yield and centelloside production, there is a need to identify suitable cultivation areas for this species. We employed ecological niche modelling with bioclimatic and soil variables to evaluate the suitability of cultivation under current and future climatic scenarios. Our results identified suitable areas for cultivating C. asiatica worldwide, indicating its potential for global commercial cultivation. However, the niche reconstruction of highly concentrated centelloside was restricted to South and Southeast Asia due to the lack of available data. When we projected the modelled niche of centelloside in these regions, we observed a lower occurrence probability in some areas, suggesting potential challenges in cost-effectiveness. Nevertheless, our results suggest a consistent future distribution for this species when we projected the modelled niche under future climates based on various socio-economic scenarios. This study not only identifies suitable areas to develop commercial cultivation for C. asiatica with highly concentrated centelloside, but also provides supporting evidence of the consistency of these areas, which can increase its sustainability.

Premise Cleomaceae is an important model clade for studies of evolutionary processes including genome evolution, floral form diversification, and photosynthetic pathway evolution. Diversification and divergence patterns in Cleomaceae remain tangled as research has been restricted by its worldwide distribution, limited genetic sampling and species coverage, and a lack of definitive fossil calibration points.MethodsWe used target sequence capture and the Angiosperms353 probe set to perform a phylogenetic study of Cleomaceae. We estimated divergence times and biogeographic analyses to explore the origin and diversification of the family. Seed morphology across extant taxa was documented with multifocal image‐stacking techniques and morphological characters were extracted, analyzed, and compared to fossil records.ResultsWe recovered a well‐supported and resolved phylogenetic tree of Cleomaceae generic relationships that includes 236 (~86%) species. We identified 11 principal clades and confidently placed Cleomella as sister to the rest of the family. Our analyses suggested that Cleomaceae and Brassicaceae diverged ~56 mya, and Cleomaceae began to diversify ~53 mya in the Palearctic and Africa. Multiple transatlantic disjunct distributions were identified. Seeds were imaged from 218 (~80%) species in the family and compared to all known fossil species.ConclusionsOur results represent the most comprehensive phylogenetic study of Cleomaceae to date. We identified transatlantic disjunctions and proposed explanations for these patterns, most likely either long‐distance dispersals or contractions in latitudinal distributions caused by climate change over geological timescales. We found that seed morphology varied considerably but mostly mirrored generic relationships.

Background and Aims: Parasitic plants represent approximately 1% of the world’s angiosperm diversity. The highest richness of parasitic plant species among angiosperms belongs to Orobanchaceae, the only family with three main nutritional stages: autotrophic, hemiparasitic, and holoparasitic. Hemiparasitic genera are the most diverse, unstudied, and sometimes neglected within Orobanchaceae. Pedicularideae, the largest tribe of hemiparasitic taxa in Orobanchaceae, contains several poorly known genera. One of these is Lamourouxia, a genus of 30 species distributed throughout the Americas, but mostly endemic to Mexico. Due to the lack of knowledge about the biogeographic patterns, ende-mism, and conservation status of Lamourouxia species, the objectives of this study were to estimate their species richness and endemism, determine the areas of endemismin the Americas, and assess their conservation status.Methods: Applying a taxonomic revision of physical and digitized herbaria specimens, citizen science observations, and scientific open access databases, we conducted biogeo-graphic analyses for the whole genus. Moreover, the conservation status of all Lamourouxia species was assessed following the IUCN Red List guidelines.Key results: The highest species richness, highest weighted endemism, and corrected weighted endemism values occurred in southern Mexico. Three areas of endemicity were distributed throughout western Mexico. Four species were classified as Endangered (EN), and three as Critically Endangered (CR) according to the IUCN risk categories. Endemic and rarely recorded Lamourouxia species were mostly distributed in unprotected areas in the Sierra Madre del Sur, Mexico.Conclusions: The Mexican Transition Zone is the center of diversification of Lamourouxia, and one third of the genus is endemic to this region. It is strongly encouraged to carry out actions to conserve threatened species of Lamourouxia, which are distributed in the Sierra Madre del Sur, the biogeographic province with the highest number of endemic species in Mexico.

Background: The genus Pinguicula harbors 110 species, of which 53 are distributed in Mexico. The formation of the Mexican mountains has favored the Pinguicula diversification. Pinguicula specimens collected in the State of México, along the Trans-Mexican Volcanic Belt (TMVB) do not correspond with any known species. Questions: Do the collected specimens belong to a new species? What is its conservation status? How many Pinguicula species are there along the TMVB and how do they differentiate? How is the Pinguicula species richness distributed? Studied species: Pinguicula. Study site and dates: TMVB, 2005-2023. Methods: Based on herbarium specimens and recently collected material, a morphological analysis and description were made. Conservation status was assessed following IUCN Red List Categories and Criteria. Herbarium specimens and digital records of Pinguicula from the TMVB were examined to generate a list and key. We analyzed the richness distribution of Pinguicula by states, vegetation types, elevation ranges, and grid cells. Results: Pinguicula tlahuica is proposed as a new species. It is distinguished by the linear-spatulate summer leaves. The new species falls into the Endangered (EN) category. Along the TMVB, 16 species of Pinguicula are distributed. The State of México, Hidalgo and Michoacán, and the pine-oak forest were the richest. Pinguicula appeared between 759-3,427 m asl. The grid cell analyses revealed different areas with high richness. Conclusions: Along the TMVB, the Pinguicula species richness centered on the Eastern and Western sectors. Pinguicula crassifolia, P. michoacana, P. tlahuica, and P. zamudioana are endemic to the TMVB.

Background and Aims: Recent studies have focused on resolving the systematics of the tribe Gonolobinae of the family Apocynaceae, as well as the controversial genus Matelea s.l. However, many species within Matelea s.l. have not been evaluated phylogenetically. This is the case of M. gonoloboides, previously recognized as the type species of Urostephanus, and other taxa with similar floral morphology. The aim of this study is to test the monophyly of Urostephanus, including some species with morphology similar to M. gonoloboides. Furthermore, we evaluate the taxonomic position of the Urostephanus clade within the subtribe Gonolobinae and compare morphology among related clades. Methods: To assess phylogenetic relationships within Gonolobinae, we downloaded sequences from four loci for 94 species of the subtribe from GenBank. We extracted DNA and sequenced the trnL-F intergenic spacer and rps16 intron from four species of Dictyanthus and six species of Matelea, which are considered to belong to Urostephanus. We reconstructed the phylogeny with Bayesian inference using the maximum clade credibility tree. Based on the phylogenetic pattern, we performed morphological comparisons between the clades Dictyanthus, Polystemma, and Urostephanus. Key results: Phylogenetic analysis recovered Urostephanus as monophyletic and sister to Dictyanthus. Based on this phylogenetic pattern and floral morphology, we resurrect the genus Urostephanus. We propose eight new combinations for the species included in the phylogeny, as well as for those that share floral morphological similarity. We designate two lectotypes. Finally, we discuss aspects of morphology between Urostephanus and closely related groups. Conclusions: The current circumscription of Matelea s.l. includes species with high morphological diversity. With the phylogenetic and morphological evidence among related taxa, we support the resurrection of Urostephanus, more than 120 years after its description. These results contribute to the resolution of the systematics of Gonolobinae in Mesoamerica.

Aim To test the hypothesis that adaptive shifts leading to the assembly of tropical savannas involved coordination between bark and wood traits and to understand the underlying mechanisms.LocationTropical South America.TaxonAngiosperms (woody).MethodsWe compiled data on three bark traits (total, inner and outer relative bark thickness), wood density, maximum height, five secondary xylem traits and on species' habitat information (light environment, climate, soil and fire history) for Neotropical savanna, forest and generalist species (biome groups). We tested for pairwise and multivariate associations among traits across species and if biome group and habitat conditions explained species positions along the resulting strategy axes.ResultsTraits covaried along four different axes. The first axis was consistent with a trade‐off between fire (thick barks) and shade tolerance (low bark to diameter ratio, high vessel density) and contributed to differentiate the three biome groups according to the preference for shaded environments. Forest species also differed from savanna and generalist species in a separate axis by being more resource acquisitive. Maximum height and wood density did not strongly trade‐off with bark thickness, although maximum height was negatively covaried with relative outer bark thickness. Preference for shaded conditions was the main driver of variation in the two principal strategy axes, but temperature, fire and soil sand content also explained differences in plant stature between savanna and generalist species.Main ConclusionsAllocation to bark is constrained by trade‐offs with wood, opposing shade‐tolerant and acquisitive forest species to fire‐resistant and conservative savanna species. Rather than a single strategy axis, three axes are necessary to understand the functional differences among savanna, forest and generalist species. Because two of these axes are controlled by light availability, the associated traits tend to covary in space and time, but not across species.

The subtribe Ponerinae (Orchidaceae) includes the genera Helleriella A. D. Hawkes, Isochilus R. Brown, Nemaconia Knowles & Westc., and Ponera Lindl. Most of its species are epiphytes and usually grow on trees of the genus Quercus L. in cloud forests and temperate coniferous and broad-leaved forests; some taxa are rarely lithophytes or less frequently terrestrial. The aim of this study was to estimate the distribution of the species of the subtribe Ponerinae using ecological niche models (ENM), determine areas with highest richness and endemism rates with the occurrence data and the models obtained, and determine if the areas with highest richness and endemism recognized in this work are located within any of the conservation areas (ANPs) and/or Regiones Terrestres Prioritarias (RTPs). We reviewed 1 044 herbarium specimens from ten institutional collections, corresponding to two species of Helleriella , eleven of Isochilus , six of Nemaconia , and two of Ponera , and a geographic and taxonomic database was generated. ENM were constructed with MaxEnt 3.3; and we determine areas with highest species richness and endemism with Biodiverse 4.3. Mexico is the richest country with 21 species, followed by Guatemala with nine. The more widely distributed species are: Isochilus linearis (Jacq.) R.Br, and Nemaconia striata (Lindl.) Van den Berg, Salazar & Soto Arenas; I . oaxacanus Salazar & Soto Arenas is endemic to Mexican state of Oaxaca and N . dressleriana (Soto Arenas) van den Berg, Salazar & Soto Arenas of Morelos. The cells with higher occurrence richness and occurrence weighted endemism were located in Chiapas Highlands, and the higher occurrence of corrected weighted endemism is located in Transmexican Volcanic Belt, considered the nucleus of the Mexican Transition Zone. On the other hand, the cells with greater ENM richness and ENM weighted endemism were located in Sierra Madre del Sur, and the higher ENM corrected weighted endemism in Sierra Madre Oriental. It is suggested to change the status of the regions Cañón del Zopilote and El Tlacuache from RTPs to ANPs.

Aim Species occurrence data are valuable information that enables one to estimate geographical distributions, characterize niches and their evolution, and guide spatial conservation planning. Rapid increases in species occurrence data stem from increasing digitization and aggregation efforts, and citizen science initiatives. However, persistent quality issues in occurrence data can impact the accuracy of scientific findings, underscoring the importance of filtering erroneous occurrence records in biodiversity analyses.InnovationWe introduce an R package, occTest, that synthesizes a growing open‐source ecosystem of biodiversity cleaning workflows to prepare occurrence data for different modelling applications. It offers a structured set of algorithms to identify potential problems with species occurrence records by employing a hierarchical organization of multiple tests. The workflow has a hierarchical structure organized in testPhases (i.e. cleaning vs. testing) that encompass different testBlocks grouping different testTypes (e.g. environmental outlier detection), which may use different testMethods (e.g. Rosner test, jacknife,etc.). Four different testBlocks characterize potential problems in geographic, environmental, human influence and temporal dimensions. Filtering and plotting functions are incorporated to facilitate the interpretation of tests. We provide examples with different data sources, with default and user‐defined parameters. Compared to other available tools and workflows, occTest offers a comprehensive suite of integrated tests, and allows multiple methods associated with each test to explore consensus among data cleaning methods. It uniquely incorporates both coordinate accuracy analysis and environmental analysis of occurrence records. Furthermore, it provides a hierarchical structure to incorporate future tests yet to be developed.Main conclusionsoccTest will help users understand the quality and quantity of data available before the start of data analysis, while also enabling users to filter data using either predefined rules or custom‐built rules. As a result, occTest can better assess each record's appropriateness for its intended application.

Besleria, a genus of perennial herbs, shrubs, or small trees growing in the understorey of rainforests, is one of the largest genera of neotropical Gesneriaceae, with over 165 species. Despite the ecological importance and ubiquity of Besleria in rainforest ecosystems, taxonomic and evolutionary studies of Besleria are limited. Here, we generated a phylogenetic analysis of Besleria using four nuclear and chloroplast DNA regions (ITS, matK, rps16, and trnL-trnF) covering more than 50% of the recognized species, along with two secondary calibration points to infer divergence times. Our results support the monophyly of Besleria and allowed us to revise the infrageneric classification and biogeographical history of the genus. We identified five major clades that do not correspond to sections or subsections in previous classifications. These clades are well circumscribed geographically but remain difficult to characterize using previously hypothesized morphological characters. Biogeographical reconstructions indicate an origin in the northern Andes during the Middle Miocene (ca. 15 Mya). The current distribution patterns of this plant group have been significantly shaped by geological and climatic events, particularly Andean uplift and the formation of the Panama Isthmus.