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The stereotyped floral morphology of Neotropical Malpighiaceae species-zygomorphic and calyx with oil glands-is correlated with oil-bee pollination. In contrast, the floral trends of the Paleotropical lineages are actinomorphy and lack of calyx glands, probably due to the absence of oil-collecting bees. The Paleotropical genus Acridocarpus is an exception because of its zygomorphic, gland-bearing flowers. Glands throughout Acridocarpus inflorescences were morphoanatomically evaluated to verify the occurrence of patterns related to species and geographic distribution. Herbarium (25 species) and fresh samples of A. longifolius were processed according to standard anatomical techniques. To verify the presence of glucose and protein, strip tests were applied to the exudate. Fresh samples were fixed and submitted to histochemical tests. Based on the occurrence, number and placement of glands, three distribution patterns were recognized on the bracteole and ten on the calyx. Bract, bracteole and sepal glands have a typical nectary structure with a palisade-like epidermis and vascularized parenchyma. Glands were classified as short-stalked, sessile or immersed. Histochemical tests performed on bract and sepal glands of A. longifolius were positive for proteins, polysaccharides and phenolic compounds, and negative for oil compounds. Glucose and protein were detected in the exudate. These results allow us to recognize the glands in Acridocarpus inflorescences as nectaries. This comprehensive morphoanatomical study helps to clarify the correlation between patterns of floral morphology and secretion consumers, as well as to better understand floral evolution in Malpighiaceae across their dispersal events.

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.

Knowledge of the geographic distribution of plants is essential to underpin the understanding of global biodiversity patterns. Vascular epiphytes are important components of diversity and functionality of Neotropical forests but, unlike their terrestrial counterparts, they are under-represented in large-scale diversity and biogeographic analyses. This is the case for the Atlantic Forest - one of the most diverse and threatened biomes worldwide. We provide the first comprehensive species list of Atlantic Forest vascular epiphytes; their endemism patterns and threatened species occurrence have also been analyzed. A list with 2,256 species of (hemi-)epiphytes - distributed in 240 genera and 33 families - is presented based on the updated Brazilian Flora Checklist. This represents more than 15% of the total vascular plant richness in the Atlantic Forest. Moreover, 256 species are included on the Brazilian Red List. More than 93% of the overall richness is concentrated in ten families, with 73% represented by Orchidaceae and Bromeliaceae species alone. A total of 78% of epiphytic species are endemic to the Atlantic Forest, in contrast to overall vascular plant endemism in this biome estimated at 57%. Among the non-endemics, 13% of epiphytic species also occur either in the Amazon or in the Cerrado - the other two largest biomes of Brazil - and only 8% are found in two or more Brazilian biomes. This pattern of endemism, in addition to available dated phylogenies of some genera, indicate the dominance of recent radiations of epiphytic groups in the Atlantic Forest, showing that the majority of divergences dating from the Pliocene onwards are similar to those that were recently reported for other Neotropical plants.

Hirtella (Chrysobalanaceae) comprises about 107 species and less than 10% of its diversity has been sampled in palynological studies, which have only used light microscopy. To better understand the pollen morphology of the genus, pollen grains of fourteen species were examined: H. angustifolia Schott ex Spreng., H. bahienis Prance, H. bicornis Mart. & Zucc., H. ciliata Mart. & Zucc., H. corymbosa Cham. & Schltdl., H. glandulosa Spreng., H. gracilipes (Hook.f.) Prance, H. insignis Briq. ex Prance, H. martiana Hook.f., H. prancei Asprino & Amorim, H. racemosa Lam., H. santosii Prance, H. sprucei Benth. ex Hook.f., and H. triandra Sw. All of the species occur in the state of Bahia, Brazil, and belong to Hirtella sect. Hirtella. The pollen of Hirtella duckei Huber, an Amazonian species that belongs to Hirtella sect. Myrmecophila, was also analyzed for comparison. The pollen grains were acetolyzed, measured, described, and photomicrographed using light microscopy, and subsamples of acetolyzed material were also analyzed using scanning electron microscopy. The pollen of the studied species presented features similar to those previously reported for Hirtella, such as size, shape, number of apertures, and general features of the exine. Based on the SEM analysis, three ornamentation patterns of the exine (microreticulate-rugulate, rugulate-perforate, and psilate-perforate) are reported for the first time for the genus. Little could be inferred about the taxonomy of Hirtella based on the pollen morphology, and there were no pollen characters for H. duckei that corroborate or refute its separation in a different section from the other species studied. Nevertheless, the present study provides new data about Hirtella that contribute to what is known about the pollen morphology of the genus.

We investigated the timing of origin and past connections between Andean and Atlantic Seasonally Dry Tropical Forests in South America based on the biogeographical history of Amorimia, a genus of Malpighiaceae restricted to South America. We used a time-calibrated phylogenetic tree based on three cpDNA (ndhF, rpl16, trnQ-rps16) and two nrDNA (ETS, ITS) regions including all currently accepted species in Amorimia for ancestral area reconstructions. Our results show that: (1) the ancestor of Amorimia originated in Atlantic dry forests around 22 Ma; (2) ancestors of both Amorimia subgenera arose in southern Brazilian dry forests from 18 to 14 Ma; (3) the remaining lineages in the genera diversified from mid-Miocene to the late-Pliocene; and (4) a history of two expansion events during early and middle Miocene, besides several colonization events in different nuclei of dry forests in South America is suggested.

Discussing homology relationships among secretory structures remains a relatively underexplored area in botanical research. These structures are widely dispersed within Malpighiales, one of the largest orders of eudicots. Within Malpighiales, both extranuptial and nuptial nectaries are present, and they do not seem homoplastic or share evolutionary connections. Particularly in Malpighiaceae, extensive research has focused on the ecological interactions mediated by glands. Botanists largely agree that elaiophores in sepals of Neotropical Malpighiaceae have evolved from extrafloral nectaries on leaves. However, the evolutionary origin of elaiophores has yet to be thoroughly examined, particularly in comparison to outgroups. This study provides empirical evidence on the ontogeny of elaiophores and investigates their evolutionary origins and homology relationships across different lineages of Malpighiales using comparative anatomy. Our findings suggest that elaiophores are likely homologous to extranuptial nectaries found in sepals of other Malpighiales lineages, originating from nectaries on leaves. This discussion is a starting point for future studies exploring the evolution of nectaries found in flowers, whether extranuptial or nuptial, and their potential origins from nectaries in vegetative organs such as leaves. Understanding these relationships could shed light on the selective pressures influencing floral morphologies.

Targeted capture of nuclear genes increasingly contributes to unravelling phylogenetic relationships that hitherto remained unresolved because of limitations of traditional Sanger sequencing. In particular, the study of tropical plant families has been compromised because they often rely on highly degraded DNA obtained from herbarium specimens. One such example is the pantropical Ochnaceae, which comprises 33 genera and approximately 550 species, occurring mostly in savannas and moist tropical forests. Here, we developed a set of baits covering about 660,000 bp from 275 nuclear genes used for the targeted enrichment based on all but one genus and more than 250 species. Using this novel dataset, we resolved the phylogenetic backbone of Ochnaceae, including that of Ochninae, and we established new relationships. Most importantly, our findings highlight that the neotropical and palaeotropical taxa of Sauvagesia form independent clades, requiring the re-erection of formerly separate genera. Ouratea and Ochna (both Ochninae), by far the most species-rich genera and represented by 120 and 41 species, respectively, came out as monophyletic. In contrast, the third-most species-rich genus, Campylospermum, is polyphyletic in two distinct clades. Ouratea, the only neotropical genus of Ochninae, was sister to the five palaeotropical genera of this subtribe. The bait kit developed in this study proved to be particularly useful for unravelling relationships within Ochninae, which includes about two-thirds of the species diversity in the family.

Aim The main goals were to assess the distributional concordance among taxa of the xeric clade of Pitcairnioideae (Bromeliaceae) to establish biogeographical units (i.e. endemic areas), and to use the results to identify conservation priorities. Location Geographical data were analysed between parallels −1° and −47° S and meridians 35°6′ and 80°1′ W, which includes the Andean region, the Chacoan subregion and the South American Transition Zone, and three global hotspots (Atlantic Forest, Cerrado and Tropical Andes). Methods Two methods were employed, parsimony analysis of endemicity (PAE) and endemicity analysis (EA), to search for the biogeographical congruence between endemic areas for 220 species. Two grid cell sizes (2° and 3°) and three criteria were employed to delimit the areas of endemism. Results The results of the PAE demonstrated eight candidate areas of endemism when applying a grid cell size of 2° and six areas of endemism with 3°. The EA optimization method, using a grid size of 2°, recovered six (consensus 75%) and four (consensus 5%) areas, and a size of 3° recovered eight (consensus 75%) and three (consensus 5%) areas. Based on consistent results of the three combined criteria and the congruence of areas of endemism, we delimited three biogeographical areas of endemism for the clade in the Chacoan subregion of South America. The following areas in Brazil were delimited: (1) south-eastern Minas Gerais, (2) north-eastern Minas Gerais, and (3) north-Eastern Goiás. Main conclusions Endemic species with congruent occurrence patterns were identified to propose primary biogeographical homologies and to highlight areas that should be prioritized for conservation of species in the xeric clade of Pitcairnioideae. Furthermore, we suggest that evolutionary and historical processes (adaptive radiation; glacial and interglacial period in the Quaternary), as well as ecological factors, could have induced the high diversification rates for this clade in South America.

Couepia is a monophyletic and exclusively Neotropical genus of Chrysobalanaceae, occurring mainly in lowland tropical forests. In eastern Brazil, Bahia is the state with the highest species richness for both the genus and family, with significant diversity in the coastal Atlantic Forest. Here we report the discovery of Couepia oxossii from Atlantic Forest, which was initially misidentified as Couepia pernambucensis. The new species is described and illustrated, and comments on its morphological traits and conservation status are also provided.

Tovomita comprises approximately 50 species that are mainly distributed in moist forests of the Neotropics. In Brazil there are 34 species, which occur in the Amazon region and along the Atlantic coast. We here describe and illustrate the Tovomita species from the Brazilian Atlantic Forest, as well as characterize the leaf morphology of these taxa. Leaves were cleared and their venation was analyzed to look for diagnostic characters related to architecture and the relationship between the secondary and intersecondary veins. Eleven species of Tovomita were recorded, which have distributions ranging from the state of Rio Grande do Norte to the state of Rio de Janeiro. An identification key, based on the analysis, and distribution maps are provided. Tovomita salimenae, a new and vulnerable species endemic to the state of Minas Gerais, is described and two synonyms and nine lectotypifications are proposed. This work also revealed that seven species have larger distributions than previously thought and two species are critically endangered (T. iaspidis and T. megantha). The most relevant characters used to identify the studied species were exudate color, venation pattern, and bud shape.