Myrteae (c. 2500 species; 51 genera) is the largest tribe of Myrtaceae and an ecologically important groups of angiosperms in the Neotropics. Systematic relationships in Myrteae are complex, hindering conservation initiatives and jeopardizing evolutionary modelling. A well-supported and robust phylogenetic hypothesis was here targeted towards a comprehensive understanding of the relationships within the tribe. The resultant topology was used as a base for key evolutionary analyses such as age estimation, historical biogeography and diversification rate patterns. One nuclear (ITS) and seven chloroplast (psbA-trnH, matK, ndhF, trnl-trnF, trnQ-rps16, rpl16 and rpl32-trnL) DNA regions for 115 taxa representing 46 out of the 51 genera in the tribe were accessed and analysed using maximum likelihood and Bayesian inference tools for phylogenetic reconstruction. Dates of diversification events were estimated and contrasted using two distinct fossil sets (macro and pollen) in BEAST. The subsequent dated phylogenies were compared and analysed for biogeographical patterns using BioGeoBEARS and diversification rates using BAMM. Myrteae phylogeny presents strong statistical support for three major clades within the tribe: Australasian group, Myrtus group and Main Neotropical Lineage. Dating results from calibration using macrofossil are an average of 20 million years older and show an early Paleocene origin of Myrteae, against a mid-Eocene one from the pollen fossil calibration. Biogeographic analysis shows the origin of Myrteae in Zealandia in both calibration approaches, followed by a widespread distribution throughout the still-linked Gondwana continents and diversification of Neotropical endemic lineages by later vicariance. Best configuration shift indicates three points of acceleration in diversification rates, all of them occurring in the Main Neotropical Lineage. Based on the reconstructed topology, several new taxonomic placements were recovered, including: the relative position of Myrtus communis, the placement of the Blepharocalyx group, the absence of generic endemism in the Caribbean, and the paraphyletism of the former Pimenta group. Distinct calibration approaches affect biogeography interpretation, increasing the number of necessary long distance dispersal events in the topology with older nodes. It is hypothesised that biological intrinsic factors such as modifications of embryo type and polyploidy might have played a role in accelerating shifts of diversification rates in Neotropical lineages. Future perspectives include formal subtribal classification, standardization of fossil calibration approaches and better links between diversification shifts and trait evolution.

Eugenia, comprising ca. 1100 species, is the largest genus of Neotropical Myrtaceae. Eugenia sect. Umbellatae (formerly referred to as “clade 9”) is the most speciose lineage of Eugenia. This study aims to better delimit E. sect. Umbellatae, to identify and understand relationships between manageable subgroups of this large clade for future discrete systematic studies and to explain biogeographical patterns in the genus. In total, 103 samples were used in this study. These include representatives of the nine clades of the “Eugenia group” with a particular focus on Eugenia clade 9, representing the morphological and geographical diversity found in the genus. Phylogenetic reconstructions were performed using maximum likelihood (ML) and Bayesian inference (BI) for the combined dataset, using the markers ITS, rpl16, psbA–trnH, rpl32–trnL, trnQ–rps16. The resultant tree was fossil calibrated and used for historical biogeographical analysis using DEC implemented in RASP. The mid Oligocene is the most likely period in which the crown node of Eugenia s.l. diversified. The earliest Eugenia appear to be associated with dry biomes and to have arisen from non–tropical southern South America, as did ancestors of the earliest American Myrteae. Eugenia subg. Pseudeugenia also most likely diversified in dry biomes, while E. subg. Hexachlamys and E. subg. Eugenia are likely to have diverged in the Atlantic Forests biome. Eugenia sect. Umbellatae is morphologically very variable; some clades can be circumscribed based on morphology while some remain morphologically undiagnosable. The study presented here provides discussion of the earliest origins of Eugenia and its response to climate–driven changes in the Neotropics as humid, forest biomes became more widespread in the Miocene. In addition, important practical conclusions are drawn regarding relationships within Eugenia. Three clades are newly classified as subgenera: E. subg. Pseudeugenia (including species of E. sect. Pseudeugenia); E. subg. Hexachlamys (including E. sect. Hexachlamys) and E. subg. Eugenia (including E. sect. Umbellatae,E. sect. Jossinia,E. sect. Phyllocalyx,E. sect. Pilothecium,E. sect. Racemosae,E. sect. Schizocalomyrtus, E. sect. Speciosae and Eugenia sect. Excelsae). Two previously unidentified clades are published as E. sect. Excelsae and recognized as E. sect. Jossinia, the latter consisting entirely of Old World species.

Eugenia currently comprises c. 1050 species and is the largest angiosperm genus in Brazil. Recent morphological and taxonomic revision of Eugenia s.l. in light of current phylogenetic knowledge necessitates a new infra-generic classification. This study, based on available systematic data, circumscribes Eugenia in its current sense and provides detailed descriptions and illustration of the resulting nine infra-generic sections: Eugenia sects. Eugenia, Calycorectes, Hexachlamys, Phyllocalyx, Pilothecium, Pseudeugenia, Racemosae, Speciosae and the largest, Umbellatae that contains two thirds of the species in the genus. Relationships between Eugenia and Old World genera currently accepted as synonyms of Eugenia (Jossinia, Monimiastrum, Myrtopsis and Chloromyrtus) are also discussed. The paper presents a wide range of changes at the sectional level resulting in five new sectional synonyms, two new combinations, a lectotypification and one name of new status. An identification key to the sections is provided.

The data recorded by the German naturalist von Martius represent a rich, unexplored source of information about the traditional uses of Brazilian plants.

No abstract

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

Floral evolution in Eugenia depends on heterochronic patterns rather than changes in complexity to promote flexibility in floral strategies. The successful early establishment of Myrteae, previously mainly linked to the key innovation of fleshy fruit, may also have benefitted from changes in flower structure.

Five species of Eugenia are described, illustrated and compared with related species. Eugenia anisomischa, from the state of Bahia, is morphologically related to Eugenia candolleana, from which it differs by the pilose leaves and flowers; Eugenia cerradensis, from the states of Goiás and Mato Grosso, E. pantanalensis, from the states of Mato Grosso and Mato Grosso do Sul, and E. tingui, from the state of Rio Grande do Norte, are morphologically related to E. stictopetala, differing largely by its indumentum, larger flowers and wider leaves, respectively; E. zigzag, from the state of Bahia, is distinct from all other Brazilian species by its zigzag branching pattern.