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Se describe e ilustra Ouratea chepelii, a la presente conocida en los Andes venezolanos. Se discute su distribución geográfica y datos ecológicos para el género Ouratea en los Andes de Venezuela. Ouratea chepelii parece estar relacionada con O. larae por su distribución fitogeográfica ya que ambas están restringidas a los Andes venezolanos. La primera especie es morfológicamente similar a O. caracasana, que se conoce de la Cordillera de la Costa y se reporta de los Andes, donde aún no se ha confirmado su presencia. Ouratea chepelii se puede distinguir fácilmente por sus inflorescencias paniculadas laterales con racimos basales de 1–3.5 cm de largo, y su carpóforo (torus) rojo brillante, semejando una pirámide alargada e invertida, casi siempre 4–5 angulado con 1–2.5 cm de largo. Actualmente, la nueva especie se conoce sólo de la vertiente norte del Parque Nacional Guaramacal y su zona de amortiguamiento entre 1800 y 2000 msnm. Sólo tres especies de Ouratea, incluyendo O. chepelii, han sido encontradas o reportadas encima de 1000 msnm en los Andes venezolanos, dos de las tres claramente endémicas. Ouratea chepelii found only in the Venezuelan Andes is described and illustrated. Geographical distribution and ecological data are discussed for the genus Ouratea in the Andes of Venezuela. Ouratea chepelii seems to be related to O. larae due to its phyto-geographic distribution since both are restricted to the Venezuelan Andes. The first species is morphologically similar to O. caracasana, which is known from the Coastal Mountains of Venezuela, and is also reported from the Andes, where its presence has not yet been confirmed. Ouratea chepelii can be distinguished easily by its lateral paniculate inflorescences with basal racemes 1–3.5 cm long, and its bright red 1–2.5 cm long carpophore (torus) that is almost always 4–5 angled and resembles an inverted elongated triangular pyramid. At present, the new species is known only from the northern slope of Guaramacal National Park and the park's buffer zone at 1800–2000 m. Only three species of Ouratea, including O. chepelii, have been found or reported to occur above 1000 m in the Venezuelan Andes, two of the three clearly endemic.

Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system.

The red ironwood ( Lophira alata ) is a relic tropical African tree species that is increasingly threatened by human activities driven by its high economic value and its vulnerability is further heightened by climate change. However, the impact of these factors on the population distribution dynamics remains unassessed, creating an urgent conservation need. We leveraged geographic occurrence records from in situ assessments and global repositories, together with environmental predictors and human footprint indices, to evaluate the distribution dynamics of L. alata across its range in Nigeria (West Africa) under current and future (2050 and 2090) climatic scenarios. Results showed that precipitation of the coldest quarter and the human footprint index are the main climatic and non-climatic factors influencing the distribution of L. alata in Nigeria, respectively. The model predicted anthropic landscapes, swamp forests, and tropical lowland forests zones in southern Nigeria as the climatically stable and suitable habitats. Substantial habitat shifts are expected under future climate scenarios, with the greatest shrinkage predicted under the worst-case scenario (SSP5-8.5) by the end of the century. A significant conservation gap exists because the predicted suitable habitats lie mostly outside designated protected areas. Our integrative conservation assessment suggests that the species would likely qualify for an “Endangered” status in Nigeria, indicating a higher regional risk despite evidence of natural succession. Collectively, our study identified the factors affecting the population trend and highlights the urgent need for site-specific conservation measures to prevent potential local extinction of L. alata in Nigeria.

Plant-animal interactions occur in a community context of dynamic and complex ecological interactive networks. The understanding of who interacts with whom is a basic information, but the outcomes of interactions among associates are fundamental to draw valid conclusions about the functional structure of the network. Ecological networks studies in general gave little importance to know the true outcomes of interactions and how they may change over time. We evaluate the dynamic of an interaction network between ants and plants with extrafloral nectaries, by verifying the temporal variation in structure and outcomes of mutualism for the plant community (leaf herbivory). To reach this goal, we used two tools: bipartite network analysis and experimental manipulation. The networks exhibited the same general pattern as other mutualistic networks: nestedness, asymmetry and low specialization and this pattern was maintained over time, but with internal changes (species degree, connectance and ant abundance). These changes influenced the protection effectiveness of plants by ants, which varied over time. Our study shows that interaction networks between ants and plants are dynamic over time, and that these alterations affect the outcomes of mutualisms. In addition, our study proposes that the set of single systems that shape ecological networks can be manipulated for a greater understanding of the entire system.

Plastid DNA sequence data have been traditionally widely used in plant phylogenetics because of the high copy number of plastids, their uniparental inheritance, and the blend of coding and non-coding regions with divergent substitution rates that allow the reconstruction of phylogenetic relationships at different taxonomic ranks. In the present study, we evaluate the utility of the plastome for the reconstruction of phylogenetic relationships in the pantropical plant family Ochnaceae (Malpighiales). We used the off-target sequence read fraction of a targeted sequencing study (targeting nuclear loci only) to recover more than 100 kb of the plastid genome from the majority of the more than 200 species of Ochnaceae and all but two genera using de novo and reference-based assembly strategies. Most of the recalcitrant nodes in the family’s backbone were resolved by our plastome-based phylogenetic inference, corroborating the most recent classification system of Ochnaceae and findings from a phylogenomic study based on nuclear loci. Nonetheless, the phylogenetic relationships within the major clades of tribe Ochnineae, which comprise about two thirds of the family’s species diversity, received mostly low support. Generally, the phylogenetic resolution was lowest at the infrageneric level. Overall there was little phylogenetic conflict compared to a recent analysis of nuclear loci. Effects of taxon sampling were invoked as the most likely reason for some of the few well-supported discords. Our study demonstrates the utility of the off-target fraction of a target enrichment study for assembling near-complete plastid genomes for a large proportion of samples.

Vein networks that disobey the global scaling of major vein density with leaf size shed light on functional constraints of vein network formation in dicotyledons. Understanding their evolution, distribution and impact on vein–stomata–climate associations is an important contribution to our global view of vein network organization. Based on vein traits of 55 species of pantropical Ochnaceae, stomata and climatic niche data, and a dated molecular phylogeny, we unveil major structural shifts in vein networks through deep time, relationships between leaf size, vein and stomata traits, and their interplay with climate. Dense 2° veins, reduction of minor veins and the associated breakdown of vein–leaf size scaling evolved multiple times independently in Ochnaceae. In spite of the drastic changes in vein architecture in this venation type, vein and stomatal densities remain correlated. Our study demonstrates that shortening the major vein–stomata distance is economically not less advantageous than by increasing minor vein density, as illustrated by the same degree of coordination between vein and stomatal densities and the similar construction costs across networks with dense 2° veins and those with ‘normally’ spaced 2° veins.

Buzz pollination has been studied for over a century, yet the drivers shaping plant–pollinator interactions at the community level remain poorly understood. Although previous research has identified key functional traits associated with sonication‐foraging behavior and taxonomic relationships among floral visitors, the specific bee traits that promote effective pollination are still unclear. In this study, we investigated which morphological and behavioral characteristics of flower‐visiting bees predict pollination success within a plant community containing multiple buzz‐pollinated species. Focusing on eight co‐occurring, co‐flowering plant species with poricidal anthers, we measured stigma contact (as a proxy for pollination efficiency), visitation rates, flower and whole plant handling time, intertegular span (body size), and pollen extraction mode across different bee species. Our results showed that both morphological and behavioral traits can predict pollination success. Specifically, stigma contact was positively associated with larger body size, suggesting that larger bees are more likely to touch the stigma during visits. In contrast, longer flower and plant handling times were linked to a low likelihood of stigma contacts—traits more commonly observed in smaller bees. Bees that used floral sonication visited more flowers and plants per unit time and contacted stigmas approximately four times more frequently than non‐sonicating bees. However, detailed aspects of sonication behavior—such as the number and duration of buzzes—were not associated with pollination efficiency. These findings suggest that while bees visiting buzz‐pollinated flowers may share similar pollen extraction mechanisms, variation in physical and behavioral traits plays a crucial role in shaping pollination dynamics. We investigated how bee traits influence pollination success in a buzz‐pollinated plant community. Larger body size and floral sonication strongly predicted stigma contact, a proxy for pollination efficiency, while longer handling times were associated with reduced effectiveness. Our findings highlight the importance of both morphological and behavioral variation in shaping pollination outcomes.

The new name Ouratea cataniapoensis (Ochnaceae) is proposed to replace the illegitimate homonym O. megaphylla. Chorological and taxonomic notes about these taxa also are provided.

Species delimitation remains a crucial issue for widespread plants occurring across forest-savanna ecotone such as Lophira (Ochnaceae). Most taxonomists recognize two parapatric African tree species, widely distributed and morphologically similar but occurring in contrasted habitats: L. lanceolata in the Sudanian dry forests and savannahs and L. alata in the dense Guineo-Congolian forests. Both species co-occur along a ca. 3000 km long forest-savanna mosaic belt, constituting ideal models for investigating hybridization patterns and the impact of past glacial periods on the genetic structures in two types of ecosystems. We genotyped 10 nuclear microsatellites for 803 individuals sampled across the distribution range of Lophira. Both species exhibit similar levels of genetic diversity [He = 0.52 (L. alata); 0.44 (L. lanceolata)] and are well differentiated, consistent with taxonomic delimitation (FST = 0.36; RST = 0.49), refuting the hypothesis that they might constitute ecotypes rather than distinct species. Furthermore, L. alata displayed two deeply differentiated clusters (FST = 0.37; RST = 0.53) distributed in parapatry, one endemic to Western Gabon while another cluster extended over the remaining species range, suggests that L. alata is made of two cryptic species. We showed that rare hybrids occur in some contact zones between these three species, leaving a weak signal of introgression between L. lanceolata and the northern cluster of L. alata. At the intra-specific level, the latter species also show weak genetic structuring between Upper and Lower Guinea and the intensity did not differ strikingly between rainforest and savanna ecosystems. The discovery of a new species of Lophira with a narrow distribution in West Gabon where it is intensively exploited for its timber requires to evaluate its conservation status.

Ochnaceae DC. includes more than 600 species that exhibit potential values for environmental ecology, ornamental, pharmaceutical, and timber industries. Although studies on phylogeny and phytochemicals have been intensively conducted, chloroplast genome data of Ochnaceae species have not been fully explored. In this study, the next-generation sequencing method was used to sequence the chloroplast genomes of Ochna integerrima and Ochna serrulata which were 157 329 and 157 835 bp in length, respectively. These chloroplast genomes had a quadripartite structure and contained 78 protein-coding genes, 30 tRNAs, and 4 rRNAs. Comparative analysis revealed 8 hypervariable regions, including trnK_UUU-trnQ_UUG, rpoB-psbM, trnS_GGA-rps4, accD-psaI, rpl33-rps18, rpl14-rpl16, ndhF-trnL_UAG, and rps15-ycf1 among 6 Ochnaceae taxa. Additionally, there were shared and unique repeats among 6 examined chloroplast genomes. The notable changes were the loss of rpl32 in Ochna species and the deletion of rps16 exon 2 in O. integerrima compared to other taxa. This study is the first comprehensive comparative genomic analysis of complete chloroplast genomes of Ochna species and related taxa in Ochnaceae. Consequently, the current study provides initial results for further research on genomic evolution, population genetics, and developing molecular markers in Ochnaceae and related taxa.