Fiorella Fernanda Mazine

Suprageneric phylogenetics of Myrteae, the generically richest tribe in Myrtaceae (Myrtales)

To clarify relationships within the predominantly Neotropical and exclusively fleshy-fruited Myrteae (49 genera and c. 2,500 species), we provide a phylogenetic hypothesis for evolutionary relationships between 31 of these genera by analyzing nuclear ITS and ETS ribosomal DNA, and plastid psbA-trnH and matK DNA sequences from 75 Myrteae species and 13 outgroup taxa using parsimony and Bayesian inference. Four morphological characters are epitomized on the resulting trees, and biogeographical analyses are also performed. Myrteae are monophyletic, comprising seven clades plus two isolated taxa of unclear relationships. Morphological characters exhibit homoplasy, although in combination are useful for clade diagnosis. Biogeographical analyses are inconclusive regarding the ancestral area of the tribe, but South American colonization before northern radiation via the Andes appears likely. The largest genera, Eugenia and Myrcia s.1., have western and south-eastern South American origins, respectively.

A preliminary phylogenetic analysis of Eugenia (Myrtaceae: Myrteae), with a focus on Neotropical species

Summary. A first phylogenetic hypothesis of Neotropical Eugenia, including associated genera and species from Africa and the Pacific was produced using DNA sequence data from the nuclear (ITS, ETS) and plastid (psbA-trnH) genomes. This analysis aimed to investigate the validity of the currently recognised infrageneric groups within Eugenia as well as suites of supporting morphological characters, to determine relationships between groups and produce a framework for future taxonomic research. A total of 70 samples were analysed and the resulting topology confirms the inclusion of Neotropical genera Calycorectes, Hexachlamys, Phyllocalyx and Stenocalyx in Eugenia to preserve the monophyly of Eugenia. Within Eugenia s.l., nine clades are identified as morphologically diagnosable groups and are assigned to two genera (Eugenia and Myrcianthes). Their morphological synapomorphies are discussed. Some lineages identified by previous classifications are also supported. Preliminary phylogenetic results presented here combined with morphology point towards the need for a new subgeneric classification for Eugenia.

Myrteae phylogeny, calibration, biogeography and diversification patterns: Increased understanding in the most species rich tribe of Myrtaceae.

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.

Circumscription and synopsis of Eugenia section Speciosae Bünger & Mazine (Myrtaceae)

Abstract A new section of Eugenia (Myrtaceae) is described, segregate from Eugenia sect. Phyllocalyx. Phylogenetic studies suggest that Eugenia sect. Phyllocalyx as traditionally delimited is paraphyletic. To maintain the monophyly of each of the sections in Eugenia s.l., we herein opt to circumscribe a new section and recognize six taxa in sect. Speciosae, which has a distribution mostly in southeastern Brazil and northern South America. Nomenclatural notes are made and a taxonomic key is provided for the species of the section.

Three new species of Eugenia sect. Racemosae (Myrtaceae) from the cerrados of the state of Mato Grosso, Brazil

Three new species of Eugenia sect. Racemosae (Myrtaceae) from cerrado vegetation of central region in Brazil are described and illustrated. They are: Eugenia hatschbachii Mazine, Eugenia mattogrossensis Mazine and Eugenia glabrescens Mazine. Data on the geographic distribution and habitat are given for the new taxa.

Eugenia goiapabana (Myrtaceae), a New Species from Espirito Santo, Brazil

Abstract Eugenia goiapabana Sobral & Mazine, a new species of Myrtaceae from Espírito Santo, eastern Brazil, is described, illustrated, and has its conservation status evaluated. The new species morphologically resembles E. bocainensis Mattos, from which it differs by its glabrous, acute leaves, racemiform inflorescences, and glabrous calyx lobes.

Two new species of Eugenia sect. Phyllocalyx (Myrtaceae) from Brazil

Summary. Two new endangered Brazilian species of Eugenia are described and illustrated, E. magnisepala and E. salacifolia. Eugenia magnisepala, collected in Matas de Cipó (liana forests) in the northeastern state of Bahia, is recognisable by its larger calyx lobes, membranaceous blades and costate ovary, traits not shared with the morphologically similar species E. itacarensis, E. involucrata, E. macrobracteolata and E. regia. Eugenia salacifolia was collected in seasonal Atlantic forests of the state of Minas Gerais and is similar to E. macrantha, from which it can be distinguished by its auxotelic inflorescences and larger and persistent bracteoles and calyx lobes.