Background and aims – Integrating landscape information with genetic data offers critical insights for biodiversity conservation and management. The Gran Chaco region, one of the most biodiverse and threatened subtropical woodlands, features a highly heterogeneous landscape largely shaped by river dynamics. This study focuses on Aspidosperma quebracho-blanco , a dominant tree species in this region with ecological, commercial, medical, and conservation significance, to investigate the interactions among population genetics, landscape features, and climatic factors. Material and methods – To assess if watersheds influence the spatial distribution of genetic variability in A. quebracho-blanco , we conducted analyses of genetic variability and structure among watersheds. Based on AFLP data, we applied horizontal interpolation analysis, Mantel test, and Barrier software to identify potential barriers to gene flow among populations and compared these with topographic and hydrographic features across the Argentinian Chaco. Finally, we used Principal Component Analysis (PCA) to evaluate the influence of environmental variables on genetic diversity. Key results – Our results reveal that genetic variability is spatially structured at the regional scale. Eight potential barriers to gene flow were identified, primarily corresponding to major river systems and orographic features. PCA indicated that elevation and climate likely influence population genetic patterns. Conclusion – The observed associations among genetic structure, landscape heterogeneity, and climate provide essential insights for the management, conservation, and ecological restoration of A. quebracho-blanco in the Gran Chaco region. For in situ conservation, it is recommended that each sampled population be managed independently. In contrast, for restoration actions and ex situ conservation, management is recommended from a watershed-based perspective.
Background and aims – The Philippine archipelago harbours the world’s greatest diversity of flowering plants, yet it is identified as a global plant diversity darkspot where much of this diversity remains poorly documented and inadequately sampled. To address this knowledge gap, extensive botanical explorations have been conducted, leading to the discovery of three new Begonia species from Panay and Mindanao Islands, which are described and illustrated herein. Material and methods – All morphological descriptions and measurements are based on recently collected living and herbarium specimens. The new species are included in a phylogenetic analysis based on noncoding plastid regions (ndhA intron, ndhF-rpl32 spacer, and rpl32-trnL spacer) and the nuclear internal transcribed spacer (nrITS) region from the assembled plastome and nuclear ribosomal DNA sequences. Key results – The newly described species from Mindanao (Begonia absiana sp. nov. and B. amorosoana sp. nov.) exhibit close morphological similarities to B. acuminatissima, while the novel species from Panay (B. panayica sp. nov.) shows affinity to B. biliranensis. The phylogenetic analyses confirmed the monophyly of B. sect. Baryandra but revealed significant cytonuclear discordance and unresolved relationships within the group. All three new species were placed in a well-supported clade, but their precise relationships remain uncertain, possibly reflecting rapid diversification. Conclusion – These findings underscore an urgent need to intensify botanical exploration and conservation efforts in the Philippines to protect these unique evolutionary lineages before their habitats are lost.
Background and aims – This paper describes and illustrates a new species of Nectaropetalum (Erythroxylaceae) from the Sanaga River basin in Cameroon. The genus otherwise includes eight species: two in the Democratic Republic of the Congo, five in coastal areas of eastern and southern Africa, and one in Madagascar. Material and methods – The description of the new species is based on the study of 13 gatherings, field observations, and a comparison with available material of its congeners in BR and K. Its conservation status was assessed following the IUCN Red List Categories and Criteria. Key results – The discovery is an important westwards range extension for the genus. Nectaropetalum camerunense sp. nov. most closely resembles N. acuminatum from Tanzania in vegetative characters, but differs by its shorter sepals and short thickened pedicels (vs sessile flowers). A key to the genus Nectaropetalum is presented. The new species is endemic to the middle Sanaga basin in Cameroon, where it occurs gregariously in periodically flooded riverine forests. It is assessed as Endangered following IUCN Red List Categories and Criteria. This brings the total number of Sanaga basin riverine endemics to date to nine, all of which are currently facing significant threats from agriculture and the construction of hydroelectric dams.
Background and aims – During fieldwork in the coastal forest of Liberia, not far east from Monrovia, a mistletoe species was found that was not yet known from this country or from its neighbouring countries. It proved to be a new Emelianthe species that is described here. Material and methods – This paper is based on examination of herbarium collections of the new species and its relatives. The new species was also studied in the field. Standard taxonomic practices were applied. The conservation status of the new species is assessed following the IUCN Red List Categories and Criteria. Key results – After comparing with a revision of African Loranthaceae and Viscaceae, it became clear that the new Liberian mistletoe belongs to the genus Emelianthe . However, the only species in this genus up till now, E. panganensis , is found almost 5000 km to the east in East Africa. The Liberian plant is clearly a second Emelianthe species that differs from E. panganensis by its flower colour (purple, greenish, and white vs mainly pinkish and red), its smaller anthers (ca 8 vs 13–18 mm), and style and filaments not bending during flowering. It is the first Emelianthe species from West Africa, occurring in a relatively small area close to Monrovia in Liberia. The new species is assessed as Endangered (EN).
Background and aims – Understanding the distribution of Amazonian tree species is hindered by sparse occurrence data and strong environmental heterogeneity. Species with wide geographic ranges but restricted habitat occupancy challenge climate-only explanations of distribution patterns. Here, we investigate the environmental drivers shaping the distribution of Ragala ucuquirana-branca (Sapotaceae) and the environmental filters constraining its realized distribution. Material and methods – We compiled 72 occurrence records from herbarium specimens and forest monitoring plots across the Amazon Basin. Species distribution models were developed using an ensemble framework integrating climatic, edaphic, topographic, and land cover variables across multiple algorithms. Model performance was evaluated using threshold-independent and threshold-dependent metrics, and habitat suitability was projected across the Amazon Basin. Key results – Model performance was consistently high, indicating robust discrimination between suitable and unsuitable environments. Soil-related predictors collectively accounted for the largest share of model importance, exceeding climatic and other environmental variables. Soil pH in water emerged as the most influential predictor, followed by water vapor pressure, minimum temperature of the coldest month, and the cation exchange capacity. Although the species exhibits a broad Extent of Occurrence of ca 1.48 million km2, its Area of Occupancy is highly restricted, revealing a spatially aggregated distribution. This pattern, together with severe fragmentation among subpopulations and environmentally constrained suitable habitats, supports a preliminary conservation assessment of Endangered. Suitable habitats are concentrated in Central Amazonia and adjacent portions of Northwestern and Southwestern Amazonia, whereas marginal conditions predominated across Eastern and especially Southeastern Amazonia. Conclusion – The distribution of R. ucuquirana-branca is strongly constrained by edaphic conditions and atmospheric stability rather than by broad climatic gradients alone. This decoupling between geographic range size and effective habitat occupancy highlights ecological specialization and potential vulnerability. More broadly, the study underscores the importance of incorporating soil and atmospheric filters into assessments of species rarity, distribution, and conservation priorities in hyperdiverse tropical forests.
Backgrounds and aims – Trichanthecium is a grass genus composed of species transferred from Panicum and is positioned in an incertae sedis clade in the tribe Paniceae (“Sacciolepis grex” clade), formed exclusively by C3 taxa. Currently, the genus possesses 52 species occurring in tropical and subtropical America, Africa, and Madagascar. Trichanthecium perrieri is the only species endemic to Madagascar and is morphologically related to another endemic species: Panicum ambositrense. We evaluated the position of P. ambositrense in the “Sacciolepis grex” clade, and applied an integrative approach, combining phylogenetic, anatomical, and morphological analyses to assess whether the species belongs to Trichanthecium. Material and methods – The phylogenetic analyses were conducted using previously published plastid markers (ndhF and rbcL). Anatomical analysis was used to describe the cross-sectional and epidermal leaf anatomy, and the taxonomic treatment was based on herbarium material, focusing on the macromorphological description of the species, micromorphological description of the upper anthecium (with scanning electron microscopy), and taxonomic comparative comments to other species. Key results – The phylogenetic analyses confirmed the position of P. ambositrense within the Trichanthecium clade, in a group with T. aequinerve and T. perrieri. Anatomical analysis indicated that the species has C3 photosynthesis, based on the presence of two sheaths without specialized chloroplasts surrounding the vascular bundles and six to ten mesophylls cells with specialized chloroplasts between consecutive vascular bundles. The taxonomic analysis indicated that P. ambositrense matches the morphological concept of Trichanthecium. Conclusion – A new combination, Trichanthecium ambositrense, is presented along with its morphological description, a distribution map, an illustration, data on its distribution, habitat and phenology, a preliminary conservation status assessment (Vulnerable), and taxonomic comments on related species. The species of Trichanthecium occurring in Madagascar are listed and discussed, and an updated identification key is presented for the Old World species of the genus.
Background and aims – Crassula helmsii is a highly invasive aquatic plant in Europe, subject to international policy measures (EU Regulation 1143/2014). While its vegetative reproduction is well-documented, the role of sexual reproduction and seed ecology remains poorly understood. This study aimed to determine the germination capacity of C. helmsii seeds and revisit its potential for dormancy and seed bank formation. Material and methods – We conducted in vitro germination trials using plant material collected from ten populations in Belgium. Following cold storage (winter conditions), seeds were sown on agar, and germination was tracked. In a comparative trial, flowers from the same populations were sown on a soil substrate, with germination estimated based on the number of seeds per flower—the only method previously used to study the species. Key results – Crassula helmsii populations exhibited high germination rates, with an estimated overall mean of 68.5%. When excluding seeds that proved non-viable, germination was nearly complete (95.7%). The flower-based trial yielded lower germination (13.8%), consistent with earlier results. This lower emergence is likely real, not an artifact, and suggests environmental constraints that are relevant under more realistic germination conditions. Conclusion – Our study demonstrates that C. helmsii populations in Belgium produce numerous viable seeds that germinate readily. Considering additional evidence from the Crassulaceae family, we hypothesize that C. helmsii is self-compatible, positively photoblastic, exhibits physiological dormancy broken by chilling, and is capable of forming persistent seed banks. The species can thus combine asexual (clonal growth and dispersal) and sexual strategies (seed dispersal, dormancy, and seed bank formation). These insights have important implications for the management of this invasive species.
Background and aims – Species delimitation using multilocus coalescent-based methods has provided new insights into evolutionary processes and species boundaries. In this study, we applied a multilocus, multispecies coalescent framework to investigate species limits and estimate divergence times within the Magnolia pacifica complex, a group of endemic species from western and north-western Mexico traditionally classified based on morphological and ecological traits without explicit statistical evaluation. Material and methods – We obtained sequences of three chloroplast intergenic spacers (trnT-trnL, rpl32-trnL, trnH-psbA) and three nuclear genes (LFY, PHYA, AGT1) from 67 individuals representing all six described species and the closely related Magnolia iltisiana. Phylogenetic reconstructions were performed using Bayesian inference and maximum likelihood. Divergence times were estimated using the RelTime-ML algorithm. Species delimitation was conducted under the multispecies coalescent model using Bayesian Phylogenetics and Phylogeography (BPP) with algorithms A10 and A11. Key results – Our analyses confirm the monophyly of the M. pacifica complex within Magnolia sect. Magnolia and integrate M. iltisiana into the complex. Divergence of the complex was dated to 1.27 million years ago. Species delimitation analyses revealed five separately evolving lineages: M. pacifica (including M. talpana), M. iltisiana, M. pugana (including M. granbarrancae), M. tarahumara, and M. vallartensis, and we formally synonymize M. talpana under M. pacifica and M. granbarrancae under M. pugana. Conclusion – Pronounced morphological divergence has, in some cases, occurred within genetically cohesive lineages, highlighting a pattern of incipient differentiation. Our delimitation effectively resolves the M. pacifica species complex, providing a robust phylogenetic hypothesis and a refined taxonomic framework for understanding the diversification of Mexican magnolias and for guiding conservation priorities.
Background and aims – Tendril-climbing vines are widespread within the genus Passiflora, but in P. subg. Astrophea, the basal clade, different growth forms are observed, varying from trees to woody vines, in contrast to the herbaceous climbers of the other subgenera. Considering the shift from woody forms to specialized climbers observed in most derived lineages, this study aims to test the existence of structural characteristics that differentiate stems from P. subg. Astrophea from stems in the other, more derived subgenera. Therefore, we describe the anatomy of the stem of four of the five recognised subgenera of Passiflora, to identify and compare the structural diversity across the genus. Only Tetrapathea, a small subgenus confined to Oceania, was excluded from this study. Material and methods – Basal branches segments of 12 Passiflora species representing four subgenera (P. subg. Astrophea, P. subg. Decaloba, P. subg. Deidamioides, P. subg. Passiflora) were examined using hand sections and methacrylate microtomy with light microscopy. Samples were stained for qualitative and quantitative analysis. Comparisons between quantitative traits (vessel element diameter and length, percentage of cross-sectional area occupied by secondary xylem and sclerenchyma) among subgenera were performed using Kruskal-Wallis tests followed by Mann-Whitney U post hoc tests. Key results – Stem cross-sections showed geometric diversity, varying from circular to deeply winged forms. The characters that distinguish P. subg. Astrophea from the other species are the periderm (present/absent), the percentage of woodiness (16–20/>32), and the percentage of sclerenchyma (3/4–7/>13). Periderm with lignified phellem layers was present in all species of P. subg. Astrophea, while absent in the other subgenera. Species of P. subg. Astrophea exhibited more developed vascular cylinders, with substantially higher proportions of secondary xylem (up to ~46% of the stem cross-section) and larger amount of sclerenchyma (up to ~20%) than species of the other subgenera. Overall P. subg. Passiflora had the largest mean vessel diameters, while the species of P. subg. Astrophea which were either lianas or scandent shrubs had the smallest diameters. Conclusion – The transition from woody forms to specialized climbers in Passiflora is characterized primarily by a reduction of lignified supporting tissues (wood and sclerenchyma) combined to a delay in periderm onset demonstrating a trend towards a lighter stem construction in the tendril-climbers.
Background and aims – In the Espinhaço Range, the campos rupestres harbour many endemic acaulescent Syagrus. Populations assigned to Syagrus evansiana include geographically and ecologically distinct populations. We reassessed the two populations used in the original circumscription of S. evansiana and revealed that they represent distinct species. Material and methods – We compared morphological and anatomical characters from field collections of both populations. The pinnae anatomy was studied using light microscopy of free-hand cross sections. A diagnostic comparison with other members of the S. evansiana complex is provided, together with a distribution map. Key results – Syagrus montana sp. nov. resembles S. evansiana but differs in leaf size, inflorescence architecture, and flower arrangement. Syagrus montana shows flowers only in triads, whereas S. evansiana frequently bears tetrads and pentads. Additional diagnostic traits include indumentum on the pistil of the flowers in pre-anthesis, staminode shape, fruit and endocarp size, and several pinnae anatomy characters. An accessory vascular bundle within the expansion tissue is recorded only in S. evansiana, first recorded for the genus. Conclusion – Morphological and anatomical evidence, together with geographic isolation and habitat differences, supports recognition of Syagrus montana as a new species. Syagrus evansiana possess rare and exclusive morphological and anatomical characters. Our results highlight the need to reassess other poorly studied populations currently assigned as S. evansiana. In addition, the data presented here corroborate the Espinhaço Range and its disjunctions as one of the centres of diversity of Syagrus. The discovery of this new species reinforces the uniqueness of the local flora and its classification as a priority area for conservation.
Background and aims – Psittacanthus is the largest genus of neotropical mistletoes within Loranthaceae, comprising approximately 110 species. With 37 species recorded to date, Colombia stands as the most diverse country for this group of aerial hemiparasites. Despite this richness, a comprehensive national or regional taxonomic revision of these mistletoes is currently lacking. This study aims to update the knowledge of Colombian Psittacanthus diversity by describing a new species and reporting new records for the country. Material and methods – This study is based on an extensive literature review and the examination of herbarium material of Psittacanthus. We examined herbarium specimens using both physical collections and high-resolution digital images. Morphological analyses were conducted using dried and rehydrated samples, following the standardized specialized terminology for neotropical mistletoes. Taxonomic descriptions and diagnoses were developed to establish and test taxonomic hypotheses, ensuring a rigorous comparison between focal taxa and previously described species. Key results – A new species for the Colombian Andes is described, and four new records for the Amazonian and Andean–Amazonian Piedmont of Colombia are reported. Psittacanthus job-kuijtii sp. nov. is described and illustrated herein; this species inhabits the moist lowland forests of the Colombian inter-Andean valleys, which are areas containing exceptional biodiversity. Furthermore, P. amazonicus, P. lamprophyllus, P. pilanthus, and P. zonatus are recorded for the first time for Colombia. The description of this new species and the additional records increase the known diversity of Colombian Psittacanthus to 41 taxa and a total of 111 species for the genus.
Background and aims – Lysimachia peduncularis has not been recorded in China for nearly half a century. Its recent rediscovery in southern Yunnan provides a critical opportunity to update its taxonomic description, clarify its nomenclatural history, and re-evaluate its systematic placement using comprehensive genomic data. Material and methods – We conducted detailed comparative morphological analysis based on newly collected specimens. Molecular phylogenetic relationships were reconstructed using nrITS, three plastid DNA regions (atpF-atpH, trnL-trnF, and rpl32-trnL), and the first reported complete plastome for this species. Key results – Phylogenomic evidence strongly supports L. peduncularis as sister to a clade comprising L. laxa and L. lancifolia, nested firmly within L. subg. Idiophyton. This robust placement revises its traditional classification, which was based solely on morphology. Notably, L. peduncularis exhibits an atypical ratio of filament-to-anther length, departing from the general pattern observed in Lysimachia. While this trait remains a key diagnostic character for the subgenus, its variation in this species underscores the need for caution when using single morphological traits for infrageneric classification. Conclusion – This rediscovery not only confirms the current status of L. peduncularis in China and expands its known distribution but also resolves its phylogenetic position. These findings contribute to a more nuanced understanding of the evolutionary history and character evolution within Lysimachia.
Background and aims – The Philippines harbours 22 recognized species of Amorphophallus, with 20 endemic taxa; however, their phylogenetic relationships remain poorly understood owing to limited molecular data. This study explored the monophyly and phylogenetic placement of Philippine Amorphophallus using molecular markers. Material and methods – Two plastid markers (rbcL and matK) and nuclear ribosomal DNA (ITS1) were sequenced for 26 Philippine Amorphophallus specimens. Maximum Likelihood and Bayesian inference analyses were performed on individual and combined datasets comprising 471 GenBank sequences representing 158 Amorphophallus species and three outgroups, and 63 Philippine Amorphophallus sequences generated in this study. Key results – Philippine Amorphophallus is polyphyletic, with species distributed across different clades. A strongly supported Paeoniifolius-Manta clade was recovered, including several Philippine taxa (A. paeoniifolius, A. rostratus, A. samarensis, and A. urceolatus) characterized by sessile spadices and verruculate petioles. Two Palawan accessions (A. natolii and A. cf. natolii) grouped within A. subgenus Metandrium, distinctly separated from other Philippine species. Conclusion – Results imply two independent colonization events from northern and southern biogeographical routes of Southeast Asia and Borneo. Unresolved polytomies indicate the need for phylogenomic studies. This first comprehensive molecular phylogeny of Philippine Amorphophallus provides a foundation for systematic revisions, biogeography, and recognition of latent diversity in this megadiverse archipelago.
Background and aims – Madagascar harbours high numbers of threatened orchid species, making it critical for orchid conservation. The Itremo Massif Protected Area (Itremo Massif PA), a Key Biodiversity Area in the Central Highlands, comprises diverse habitats essential for orchid survival. Previously, only 30% of the 83 orchid species recorded in the Itremo Massif PA had been assessed for the IUCN Red List. This research documents and analyses their habitats and threats to propose conservation approaches. Material and methods – We compiled a dataset of orchid species native to the Itremo Massif PA, including information on endemicity, conservation status, habitats, and threats from IUCN Red List assessments and field observations. A species-by-habitat matrix was constructed, and species composition across habitats was analysed using a β-diversity framework. Overall β-diversity (βSOR) was partitioned into species turnover and nestedness components. We also evaluated the proportion of threatened orchid species (Critically Endangered – CR, Endangered – EN and Vulnerable – VU) associated with the primary habitats and threats in the PA. Key results – Of the 83 orchid species native to the Itremo Massif PA, 64% (53 spp.) are endemic to Madagascar and 41% (34 spp.) are threatened (1 CR, 16 EN, 17 VU). Species composition varies markedly between habitats (βSOR = 0.83), primarily driven by species turnover (0.66). Bare soil and rock host the most orchid species (60%, 50 spp.). Bare soil and rock and grassland share the most species (14%, 12 spp.), while humid forest contains the most species restricted to a single habitat (16%, 13 spp.). Orchids are primarily threatened by mining and quarrying, increased fire intensity/frequency, logging and wood harvesting, and shifting agriculture. Conclusion – Conservation should prioritise humid forest for its unique orchid species, and bare soil and rock for their richness in endemic and threatened species. Grassland also represents essential habitat for terrestrial orchids. Further research on population dynamics, pollination, and fungal interactions is needed to better assess extinction risk and manage conservation.
Background and aims – The relationships between insect species and plant functional traits are complex but vital in their ecosystem structure and functioning. Our study examined functional traits of Crambe tataria to assess their influence on insect abundance and community composition. Material and methods – The study was carried out in April–May 2024 and 2025 at four locations in Iași and Vaslui counties, Romania. We investigated the presence of insects on C. tataria inflorescences and their relationship to plant functional traits. To understand the relationships between plant functional traits (plant height and inflorescence circumference) and insect abundance, we applied a Kendall’s rank correlation test. The vegetation was classified using agglomerative hierarchical clustering, while insect community clustering was based on Euclidean distances and complete linkage. Key results – A total of 36 insect taxa were identified on C. tataria, including 30 taxa identified to species level and six identified only to the genus level. The predominant trophic group was represented by phytophagous insects. Rare or conservation-relevant species, such as Clanoptilus affinis and Lixus canescens, were also recorded. A positive correlation was found between plant height and the number of Cercopis sanguinolenta. The number of C. sanguinolenta, Eurydema ornata, and Bibio hortulanus significantly increased with inflorescence circumference. Cluster analyses (108 plots) revealed three plant associations and three distinct insect communities, mainly phytophagous or pollen-feeding. Alpha-diversity indices varied between locations: Horlești presented the highest richness, Miroslava and Vulturi presented moderate diversity, while Glodeni had lower diversity. The PERMANOVA test showed that plant height and inflorescence circumference in C. tataria significantly influenced the composition of the insect community, explaining 34.5% of the observed variation. Conclusion – Plant height and inflorescence circumference of C. tataria were significantly correlated with the abundance of some phytophagous insect species, particularly Cercopis sanguinolenta, Eurydema ornata, and Bibio hortulanus.
Background and aims - Cinchona species, the botanical source of quinine, remain essential for treating severe malaria and support rural livelihoods in eastern Democratic Republic of the Congo. Yet, increasing climate stress and land degradation threaten its future habitat suitability. This study assessed current and mid-century habitat suitability for Cinchona in North and South Kivu provinces and prioritised areas for conservation and replanting. Material and methods - Potential distributions were modelled with MaxEnt using 125 validated occurrences and ten environmental predictors (five bioclimatic, three topographic, two edaphic). To limit multicollinearity, we pre-selected variables with |r| < 0.7 and VIF < 10. Future projections used 2050s CMIP6 climates under SSP2-4.5 and SSP5-8.5. Key results - Model performance was high. Thermal variability together with elevation most strongly explained suitability, indicating a preference for moderate thermal regimes at 1,400-2,300 m. Under current climate, high suitability covers 4.13% of the study area, moderate 6.49%, low 27.67%, and 61.71% is unsuitable. By the 2050s, high suitability contracts to 1.27% (SSP2-4.5) and 1.07% (SSP5-8.5), while unsuitable area expands to 81.72% and 83.90%, respectively. High-suitability zones cluster along the eastern escarpment, notably Lubero, O & iuml;cha, Kabare, Walungu, and Butembo, whereas lowland territories such as Shabunda and Fizi become largely unsuitable. Conclusion - Our results delineate micro-refugia for in situ protection, guide climate-resilient replanting toward highlands, and indicate where ex situ measures and assisted restoration will be needed under future climate conditions.
Background and aims – While some plants achieve reproductive success through wind or deceptive pollination strategies, many animal-pollinated species depend on mutualistic interactions with pollinators, supported by floral cues, rewards, and microstructural adaptations. Despite the diversity within Araceae, pollination ecology remains poorly characterized for most species. Material and methods – To address this gap, this study investigates the flowering biology and pollination dynamics of Apoballis mutata, with particular focus on pistillate, transitional, and staminate phases of anthesis, followed by infructescence development and seed dispersal. Seeds germination trials were conducted on cotton wool in sealed Petri dishes, and fruit set was quantified from pistillate flower and berry counts. Scanning Electron Microscopy (SEM) was used to examine staminate floral structures and pollen distribution on pollinators. Key results – Three legitimate pollinators were identified, Colocasiomyia sp. 2 aff. bogneri, C. sp. 34 aff. bogneri, and C. sp. 17 aff. bogneri, along with two non-pollinating insect visitors, forming a co-occurring assemblage. Echinate pollen consistently adhered to the bodies of Colocasiomyia flies, confirming their role as effective pollinators. Unlike trapping system observed in some aroids, spathe movements in A. mutata regulated pollinator behaviour, allowing repeated visits and efficient pollen transfer. Pollinator diversity declined from the pistillate to staminate phases, with C. sp. 2 aff. bogneri remaining dominant, particularly in creamy green-spathed inflorescences. Overall fruit set exceeded 90%, with creamy melon-red spathes achieving 77.90% and creamy green spathes surpassing 100%. Conclusion – These findings reveal a specialized, non-trapping pollination system in A. mutata, enhancing understanding of its mutualistic relationship with Colocasiomyia flies and contributing new insights into the pollination ecology of Araceae.
Background and aims – The Paleotropical tribe Vanguerieae (Rubiaceae) is centred in Africa and Madagascar. In Madagascar, many of its ca 150 species are functionally dioecious, belonging to the small genus Bullockia and two large genera, Pyrostria (~90 species) and Peponidium (~50 species). These species estimates include many undescribed species, two of which are formally described here. Material and methods – A Bayesian inference of ITS sequence data from Vanguerieae was performed to pinpoint the generic placement of the new taxa. Morphological studies were conducted based on standard methods of herbarium taxonomy. The new species are described in detail, illustrated, and compared to morphological similar species. Distribution maps are presented and the preliminary conservation status of the new taxa was evaluated using IUCN criteria. Key results – Two new species of Malagasy Vanguerieae are described. ITS data place one in the genus Peponidium and one in the genus Pyrostria. Peponidium calciphilum sp. nov. is endemic to the Tsingy of Ankarana in northern Madagascar, while Pyrostria multilocellata sp. nov. is restricted to the spiny thickets in dry southern and southwestern Madagascar. Both species occur on limestone and in dry vegetation types, have 4-merous, functionally dioecious flowers, and bilocular fruits. Peponidium calciphilum sp. nov. is characterized by ovate, sessile leaves with cordate bases, well-developed subulate stipules, glabrous shoots, ovaries, and calyces, distinct tufts of hairs at the tips of the calyx lobes, and vaulted corolla lobes with well-developed appendages. Pyrostria multilocellata sp. nov. is characterized by very small, strongly coriaceous to almost succulent leaves, single-flowered male and female inflorescences, minute flowers, and multilocellate anthers in the male flowers. Peponidium calciphilum sp. nov. is considered as Endangered, whereas Pyrostria multilocellata sp. nov. is estimated to be Near Threatened.
Background and aims – The newly described species Arcytophyllum leymebambense sp. nov. (Rubiaceae) from the Amazonas department of northern Peru represents an isolated lineage within the monophyletic genus Arcytophyllum. This study aims to describe its distinctive morphological features and ecological context, assess its phylogenetic position, and discuss its implications for the diversification of the genus in the Andes. Material and methods – Morphological observations were conducted on herbarium specimens and field collections from the type locality. Phylogenetic analyses were performed using nuclear and plastid DNA sequences from the tribe Spermacoceae, with particular emphasis on Arcytophyllum. Key results – Arcytophyllum leymebambense sp. nov. is morphologically distinct from its congeners by its acuminate leaf and sepal apices, hirsute-lanuginose seeds, and the presence of protective hooks surrounding the ovary. It inhabits humid, high-elevation grasslands known as “Jalca,” where it coexists with a diverse assemblage of montane species. The species appears to be endemic to the region and is currently known from only three populations. Its restricted distribution, combined with potential threats such as overgrazing and fire, supports a preliminary conservation assessment as Critically Endangered (CR). Conclusion – The discovery of Arcytophyllum leymebambense sp. nov. highlights the underestimated diversity of Andean Rubiaceae and provides evidence that Andean species form a grade within the diversification of Arcytophyllum. This pattern suggests a historical northward expansion of the lineage into the high mountains of Panama and Costa Rica.
Background and aims – Oldenlandia is a taxonomically complex and polyphyletic genus with approximately 160 pantropical species distributed across more than ten clades. In an ongoing integrative review of South American representatives, distinct morphological and ecological variation was detected among specimens previously assigned to O. filicaulis. This prompted the recognition and description of a new species, which is circumscribed here based on multiple lines of evidence. Material and methods – Eighty herbarium specimens were analysed. Classical taxonomic techniques were employed, including type revision, and different databases were consulted. A principal component analysis based on 19 climatic and nine edaphic variables was conducted, together with the comparative analysis of micromorphological floral, carpological, and pollen characteristics was performed using optical and scanning electron microscopy. Line drawings, geographical records mapping, and a preliminary conservation assessment were also carried out. Key results – The analysed specimens have a set of unique characteristics when compared with O. filicaulis, such as floral merosity, variation in the shape and size of calyx and corolla lobes, type and distribution of corolla indumentum, presence of a pubescent style (vs glabrous), number of pollen apertures, and variation in sexine ornamentation. Distribution patterns also differ: O. filicaulis occurs in Bahia, Ceará, and Piauí, whereas the differentiated specimens are recorded exclusively in the high-altitude rupestrian grasslands in Bahia. Conclusion – The combined evidence supports the recognition of a new species. Further molecular phylogenetic studies are needed to clarify its placement within Spermacoceae and its relationships to other species of the genus, especially the South American taxa. This new species discovery reinforces the extraordinary diversity and endemism of the Brazilian rupestrian grasslands. An identification key for all Oldenlandia species occurring in Brazil is provided.
