Abstract— A new tree species of Ecclinusa (Sapotaceae, Chrysophylloideae) from Central Amazonia is described and illustrated. It occurs in non-flooded upland forests (terra-firme) in the municipalities of Manaus, Presidente Figueiredo, and Rio Preto da Eva in Amazonas state, Brazil. Ecclinusa nervosa sp. nov. resembles E. ulei, E. parviflora, and the sympatric E. guianensis, as these species share overall similar foliage at first sight. However, it differs by the combination of the presence of intersecondary veins (vs. absent in all congeners, except in E. lancifolia) and flowers with a sparse tomentulose indumentum inside the sepals (vs. glabrous inside in all congeners, except in E. ramiflora and E. psilophylla) and shorter styles (≤ 0.7 mm long vs. > 0.7 mm long in the morphologically similar taxa). We compare the new species with similar taxa through diagnostic morphological features, geometric morphometrics, and infrared spectral analyses of dried leaves. Additionally, we provide information on habitat, distribution, phenology, and a preliminary conservation assessment. An identification key for Ecclinusa species from the Brazilian Amazonia is also presented.

Abstract— The objectives of this research were to assess variation in nrDNA internal and external transcribed spacer (ITS and ETS) sequences of the morphologically diverse genus Dieteria and to determine how well the results of phylogenetic analysis corresponded with morphological variation, taxonomy, and geographic distribution. The first of two analyses included 39 samples from throughout the range of the genus and representing 13 of the 16 currently accepted varieties, with ITS and ETS sequences combined to obtain the greatest resolution possible. This analysis produced phylogenies containing three major clades. One of the three consisted of samples from Washington, Oregon, and northern California. The second one included samples from southern California and western Arizona, plus additional ones from northern California, northern Nevada, and southeastern Idaho. The third clade was the largest and consisted of samples from the remaining part of the distribution of Dieteria. Comparison of the results with current taxonomy and morphological characteristics showed little correspondence between the molecular phylogeny and either taxonomy or morphology, suggesting multiple occurrences of convergent evolution. There were some correlations with geographic distributions. Except for the second and third clades’ distributions overlapping in some areas, the distributions of the three were mostly distinct from one another; smaller clades within them were also correlated with distributions. The second analysis included cloned sequences of five additional samples that were shown by initial sequencing efforts to contain many polymorphic nucleotide positions. In the results, the ITS and/or ETS for all five samples were placed in multiple positions some distance apart, indicating that these samples obtained their ITS and/or ETS sequences from distantly related ancestors through hybridization between members of two of the three major clades.

Abstract— A new neotropical genus, Sumacoa, with a single species, S. barbata J. L. Clark & D. A. Neill, is described from the Cordillera del Cóndor, Cordillera Galeras, and eastern slopes of the Andes in Ecuador and is placed in the family Gesneriaceae and tribe Beslerieae. The placement of Sumacoa in the tribe Beslerieae is strongly supported by molecular sequence data generated from analyses of nuclear ribosomal DNA internal transcribed spacer region (ITS). Sequence data were evaluated from 34 taxa representing all genera from the tribes Beslerieae and Napeantheae. Sumacoa is characterized by the following unique combination of relatively uncommon characters in the Gesneriaceae: arborescent habit, a tardily dehiscent globose bivalved capsule, and elongate multicellular trichomes clustered apically in the throat. Sumacoa is endemic to the provinces of Napo and Morona-Santiago and in lower montane cloud forest from the Cordillera del Cóndor and Cordillera Galeras at 1200‐1800 m elevation, as well as one locality on the eastern slopes of the Eastern Cordillera of the Andes. A key and a table are presented for differentiating Sumacoa from other genera. Based on IUCN guidelines, a preliminary conservation status of Vulnerable (VU) is provided for S. barbata.

Abstract— Past glacial periods were highly disruptive to plant species distributions in mid-latitude mountain belts, such as the European Alps, and drove many species to survive in peripheral or nunatak refugia. Progressive glacial retreat during the late Pleistocene and Holocene is thought to have triggered a mass recolonization event in the European Alps. Here, we asked whether this recolonization event has left a spatial legacy in the floristic patterns of the extant Alpine flora, and if so, how strongly this determines floristic patterns in comparison to present-day landscape and climatic drivers. We built on approximately 6 million data points sourced from the Global Biodiversity Information Facility and herbaria to build plant species ranges within a 10 × 10 km grid system laid across the European Alps, and then calculated species assemblage turnover across the grid. Additionally, we used a recent species-level molecular phylogeny encompassing over 80% of the Alpine flora to calculate standardized phylogenetic diversity, phylogenetic endemism, and phylogenetic turnover between grid cells. Using spatial autoregressive and generalised dissimilarity modelling, we showed that all floristic measures vary significantly, albeit weakly, with three key post-glacial variables: climate change velocity, time since deglaciation, and distance from the nearest refugium. Unexpectedly, differences in species’ dispersal ability did not explain these patterns. The post-glacial variables have little explanatory power relative to contemporary climate and landscape drivers. We conclude that post-glacial recolonization of the Alps is largely complete for the flora as a whole, and that the spatial structure of the extant flora is primarily driven by the contemporary environmental conditions.

Abstract— Melocactus (L.) Link & Otto (Cactaceae) is a widely distributed genus in the Neotropical region and has fascinated the botanical community since the 15th century due to its unique appearance. Even though this genus has been studied for centuries, its diversification, phylogenetic relationships, and species delimitation have not been evaluated using comprehensive taxon sampling and genetic data. Here, we inferred maximum likelihood and coalescent phylogenies using the Cactaceae591 genomic dataset and investigated the ancestral range and potential environmental variables associated with Melocactus diversification. Ancestral character reconstructions were performed using edaphic and climatic data. A well-resolved Melocactus phylogeny was estimated, allowing the redefinition of informal infrageneric groups and the taxonomic rearrangement of some taxa. Melocactus diversification occurred during the Pleistocene, mainly in the Caatinga ecoregion. The ancestral character reconstructions suggest that the observed species relationships and distribution patterns in Melocactus result from the interplay of climatic and edaphic factors, highlighting a complex evolutionary history for the genus.

Abstract— This study reconstructs the molecular phylogeny and biogeographical history of Stizophyllum (Bignonieae, Bignoniaceae), a small genus of Neotropical lianas, distributed from southern Brazil to Central America. We sampled 33 individuals representing the breadth of morphological variation and geographical distribution of the three species recognized to date, i.e., Stizophyllum inaequilaterum, Stizophyllum perforatum, and Stizophyllum riparium. Bayesian and maximum likelihood approaches led to congruent topologies. A putative new species from Amazonia collected in the Brazilian state of Pará, Stizophyllum coriaceum, sp. nov., was recovered as sister to the remaining species of the genus, confirming that it represents a distinct taxon. Furthermore, all Stizophyllum riparium from Central America emerged as a separate clade, leading to the reestablishment of Stizophyllum punctifolium. These findings corroborate a broader circumscription of Stizophyllum perforatum (including all Stizophyllum from the Brazilian Atlantic Forest and Dry Diagonal) and a narrower circumscription of Stizophyllum inaequilaterum (restricted to Western Amazonia and Central America), while indicating that Stizophyllum riparium is not monophyletic and best divided into two taxa: Stizophyllum riparium and Stizophyllum punctifolium. The molecular phylogenetic findings are corroborated by morphological data, and the appropriate taxonomic changes are proposed. In sum, a broader Stizophyllum, with five species is recognized, and an updated synopsis of the genus is presented. Divergence time estimates indicate that the stem node of Stizophyllum originated during the late Eocene, while most of the diversification within the genus occurred much later during the Miocene and Pliocene, periods of intense geological activity in South America. Ancestral area reconstructions inferred Lowland Amazonia as the most likely distribution of the MRCA of Stizophyllum. Five dispersal events and three local extinction events led to the current distribution of the genus.

Abstract— The landscape of western North America has dramatically transformed since the Miocene to become increasingly heterogeneous, in turn promoting the evolution of many rapidly radiating angiosperm lineages. Phylogenetic relationships of these recently and rapidly radiating groups are difficult to resolve as there is little genetic variation among species and a high degree of noise from incomplete lineage sorting and hybridization. Mentzelia section Bartonia (51 species; Loasaceae) exemplifies this problem well. The clade has been investigated with Sanger sequencing, RADSeq, and genome skimming methods, however, most species relationships remain elusive due to low genetic variability. To better infer species relationships, we applied a hybrid enrichment approach with the Angiosperms353 probe set and implemented a novel bioinformatics workflow that aimed to maximize phylogenetic signal and minimize noise from low-quality sequences, paralogy, and incomplete lineage sorting. Our phylogenomic approach increased phylogenetic resolution of species relationships compared to previous studies based on nrDNA loci. Although a few species relationships still lack strong support, our results indicate that our methods were effective in phylogenetic inference of this recently and rapidly evolving lineage from western North America. To better characterize major groups in the Section, we propose the formal designation of three subsections: Decapetala, Multicaulis, and Multiflora.

Abstract— Neea contracta, a new species known only from central Amazonia, in Brazil, is described. In addition to morphological characteristics, we use spectral data associated with discriminant analyses as further evidence of the distinctiveness of this species. Besides the description, we provide a distribution map and notes on the taxonomy of N. contracta, a comparative table distinguishing N. contracta from morphologically similar species, and an updated key to the 18 species of Neea known for Amazonas State, Brazil.

Abstract— This paper presents a taxonomic revision of the genus Abutilon in India, supported by detailed seed morphology. Twelve species and two varieties are recognized from India and each described with their synonymy, nomenclature notes, illustrations, habitat specificity, geographical distribution, phenology, and specimens observed in various herbaria across India. A comprehensive key is provided for the identification of species and varieties. Lectotypes are designated for nine names including a second-step lectotype for A. fruticosum. Infraspecific taxa are reevaluated, resulting in the synonymization of A. bidentatum var. major, A. fruticosum var. chrysocarpa, and A. hirtum var. heterotrichum with their respective species. A. indicum subsp. guineense is reinstated as distinct species and A. pakistanicum is determined to be an excluded species. Throughout the study, seed micro-morphology is identified as a crucial tool for discriminating taxa at the interspecific and infraspecific levels. The previously proposed infraspecific classification of A. indicum is invalidated in this study which is corroborated by morphology and distribution of the taxa. This study provides the first comprehensive taxonomic account of the genus Abutilon in India with discussion on fruit dehiscence.