Monophyletic Species Groups Research Articles

Systematic revision of the ant subfamily Leptanillinae (Hymenoptera, Formicidae).

The genus-level taxonomy of the ant subfamily Leptanillinae (Hymenoptera: Formicidae) is here revised, with the aim of delimiting genus-level taxa that are reciprocally monophyletic and readily diagnosable based upon all adult forms. This new classification reflects molecular phylogenetics and is informed by joint consideration of both male and worker morphology. Three valid genera are recognized in the Leptanillinae: Opamyrma, Leptanilla (= Scyphodonsyn. nov., Phaulomyrma, Leptomesites, Noonillasyn. nov., Yavnellasyn. nov.), and Protanilla (= Anomalomyrmasyn. nov., Furcotanilla). Leptanilla and Protanilla are further divided into informal, monophyletic species groups. Synoptic diagnoses are provided for all genera and informal supraspecific groupings. In addition, worker-based keys to all described species within the Leptanillinae for which the worker caste is known are provided; and male-based keys to all species for which males are known, plus undescribed male morphospecies for which molecular data are published. The following species are described as new: Protanillawallaceisp. nov., Leptanillaacherontiasp. nov., Leptanillabelantansp. nov., Leptanillabethyloidessp. nov., and Leptanillanajaphallasp. nov.

Revisiting the morphological species groups of West-Palearctic Aphaenogaster ants (Hymenoptera: Formicidae) under a phylogenetic perspective: toward an evolutionary classification

The West-Palearctic region is a diversity hotspot for the ant genus Aphaenogaster. Species in this region are characterized by high morphological variation, which has led to their subdivisioninto different infrageneric groups. The very first classification in three subgenera, dated 1915, was gradually replaced by eight species-groups. To probe the evolutionary consistency of these species-groups, we sequenced 46 species from all eight species-groups and biogeographic sectors of the region, using one mitochondrial (COI) and six nuclear markers (EPICs), and interpreted the results by integrating qualitative morphology. Our results demonstrate the non-monophyly of all formerly recognized subgenera and species-groups, except for the crocea group. We use the phylogeny and morphological characters to propose a new classification of six monophyletic species-groups (crocea, gibbosa, graeca, pallida, sardoa, subterranea). The pallida, subterranea and sardoa (formerly testaceopilosa) groups attain monophyletic status by reassigning a few taxa. The gibbosa group is to be considered exclusively Western-Mediterranean until further assessments of similar Eastern species. The new graeca group is established by including former members of the splendida and subterranea groups, while the polyphyletic cecconii, obsidiana, and splendida groups are dismissed. Notably, the first is not part of the tropical Deromyrma clade as previously thought, while at least two independent clades which require further investigation are composed of species from both the cecconii and splendida groups, suggesting repeated morphological convergences based on similar ecological adaptations. Finally, A. cardenai is confirmed to be a significantly divergent lineage. In addition, three Aphaenogaster species are moved to different genera: Messor asmaae (Sharaf, 2018) comb. nov., Messor isekram (Bernard, 1977) comb. nov., and Pheidole sarae (Sharaf, 2018) comb. nov. Further studies should address the evolutionary relationships between the clades recovered in this study.

Stenamoeba aeronauta n. sp., a new case of sibling species in the order Thecamoebida (Amoebozoa, Discosea)

A new speciesStenamoeba aeronautan. sp.was isolated from a culture of large thecamoebids during laboratory studies. Our study of this species showed almost complete morphological identity with the well-known speciesStenamoeba stenopodia. Despite the morphological similarity and proximity in the phylogenetic tree, significant differences in the sequence of the 18S rRNA gene forced us to recognize it as a new species. Known species ofStenamoebahave noticeable morphological differences, but the discovery of the new speciesshows that cryptic speciation appears in this amoeba genus as well as in many others, likeThecamoebaorVannella. In contrast with many other amoebae genera, the number of available 18S rRNA gene sequences exceeds that of morphologically described isolates. So, it is not yet possible to suggest the application of the names of monophyletic species groups, as it was recently proposed forThecamoebaspecies, since every clade ofStenamoebacontains both sequences of species with known morphology and with unknown ones.Overall, the present study further confirms that probably almost all “classical” morphospecies of amoebae may represent a cluster of a sibling species, showing remarkable differences at the molecular level.

Integrating morphology with phylogenomics to describe four island endemic species of Temnothorax from Sicily and Malta (Hymenoptera, Formicidae)

Temnothorax (Myrmicinae, Crematogastrini) is one of the most diverse Holarctic ant genera, and new taxonomic advancements are still frequent worldwide. The Mediterranean region, a global biodiversity hotspot characterized by a complex geographic history, is home to a substantial portion of its described diversity. Sicily is the region’s largest island and, as ongoing investigations are revealing, it is inhabited by a long-overlooked but highly diverse ant fauna that combines multiple biogeographic influences. We combined qualitative and quantitative morphology of multiple castes with phylogenomic analysis based on ultra-conserved elements (UCEs) to describe four species of Temnothorax endemic to Sicily and the neighboring Maltese Islands (Sicilian Channel). Three of these species, T. marae Alicata, Schifani & Prebus sp. nov., T. poldii Alicata, Schifani & Prebus sp. nov. and T. vivianoi Schifani, Alicata & Prebus sp. nov., are new to science, while a redescription clarifies the identity of T. lagrecai (Baroni Urbani, 1964). These descriptions highlight the current difficulties of delimiting monophyletic Temnothorax species groups based on morphological characters. The intra-insular endemicity patterns we revealed highlight the importance of Mediterranean paleogeography to contemporary ant diversity and distribution in the region.

Integrative systematic revision of a new genus of Eumolpinae (Coleoptera: Chrysomelidae) endemic to New Caledonia: Dematotrichus gen. nov. and its numerous new hairy species

The monophyletic group of species around Dematochroma pilosa Jolivet, Verma & Mille is identified in this work by combining information from mitochondrial DNA data and morphological features. A series of defining traits diagnosing this species assemblage from its closest phylogenetic relatives, including the genera Thasycles Chapuis and Atrichatus Sharp, is used to argue for its taxonomic separation and propose a new genus, named Dematotrichus gen. nov. Both Dematochroma pilosa and Montrouzierella hispida Jolivet, Verma & Mille are transferred to the new genus as D. pilosus (Jolivet, Verma & Mille) comb. nov. and D. hispidus (Jolivet, Verma & Mille) comb. nov., and 11 new species are described: D. capillaris sp. nov., D. capillosus sp. nov., D. comans sp. nov., D. crinitus sp. nov., D. comatulus sp. nov., D. hirtus sp. nov., D. hirsutus sp. nov., D. horridus sp. nov., D. pubescens sp. nov., D. setosus sp. nov. and D. villosus sp. nov. The work includes an identification key for all the species in the new genus. http://zoobank.org/urn:lsid:zoobank.org:urn:lsid:zoobank.org:pub:0A3640A2-28B4-4592-9883-0DDB82BE4DB2

A phylogenomic approach to species delimitation in the mango fruit fly (Bactrocera frauenfeldi) complex: A new synonym of an important pest species with variable morphotypes (Diptera: Tephritidae)

AbstractSpecies that are dispersed across oceanic islands can have strong population structure due to genetic isolation, which makes it difficult to determine realistic and meaningful species boundaries. This becomes especially problematic when pest species are involved, and can result in undetected new invasions. The mango fruit fly, Bactrocera frauenfeldi (Schiner), is currently considered to be one of five morphologically similar members in a monophyletic species group distributed across Southeast Asia, Australasia, and Oceania, including three major pests. We used a phylogenomic approach with highly multiplexed amplicon sequencing to test species limits and evaluate the relationships among species in the B. frauenfeldi species complex and two closely related species. We obtained sequence data from 196 specimens for 395 nuclear DNA loci, totalling 102 kb, of which 2.2 kb were parsimony informative sites. Based on morphology, biogeography, and phylogenetic analyses, we conclude that there are five distinct species in the complex in our phylogeny. Our results show that the morphological differences between B. frauenfeldi and B. albistrigata (de Meijere) are part of a continuum that cannot be phylogenetically separated into monophyletic groups. We therefore synonymize the names of two major pests: B. albistrigata syn. rev. with B. frauenfeldi, making B. frauenfeldi now recognized as a widespread pest across Australasia and Southeast Asia. We evaluated the use of COI for pest recognition and conclude that it cannot reliably distinguish between six of the seven species we studied, thus new molecular approaches will be necessary for effective management and the prevention of incursions.

Homing in on Endogenous Badnaviral Elements: Development of Multiplex PCR-DGGE for Detection and Rapid Identification of Badnavirus Sequences in Yam Germplasm.

Viruses of the genus Badnavirus (family Caulimoviridae) are double-stranded DNA-reverse transcribing (dsDNA-RT) plant viruses and have emerged as serious pathogens of tropical and temperate crops globally. Endogenous badnaviral sequences are found integrated in the genomes of several economically important plant species. Infection due to activation of replication-competent integrated copies of the genera Badnavirus, Petuvirus and Cavemovirus has been described. Such endogenous badnaviral elements pose challenges to the development of nucleic acid-based diagnostic methods for episomal virus infections and decisions on health certification for international movement of germplasm and seed. One major food security crop affected is yam (Dioscorea spp.). A diverse range of Dioscorea bacilliform viruses (DBVs), and endogenous DBV (eDBV) sequences have been found to be widespread in yams cultivated in West Africa and other parts of the world. This study outlines the development of multiplex PCR-dependent denaturing gradient gel electrophoresis (PCR-DGGE) to assist in the detection and analysis of eDBVs, through the example of analysing yam germplasm from Nigeria and Ghana. Primers targeting the three most prevalent DBV monophyletic species groups in West Africa were designed to improve DGGE resolution of complex eDBV sequence fingerprints. Multiplex PCR-DGGE with the addition of a tailor-made DGGE sequence marker enables rapid comparison of endogenous badnaviral sequence diversity across germplasm, as illustrated in this study for eDBV diversity in yam.

Diaphorina pfanderae Aléné and Burckhardt sp. nov. (Hemiptera: Psylloidea: Psyllidae) and its association with ants on Ozoroa pulcherrima (Anacardiaceae)

ABSTRACT Diaphorina (Psyllidae: Diaphorininae) is a large Old World genus with an unusually wide range of host plants. Its most prominent member is undoubtedly the Asian citrus psyllid, Diaphorina citri, one of the most devastating citrus pests in tropical Asia and the New World where it is adventive. Recently, the species also was discovered in Africa where it appears to be spreading quickly. Detection and correct identification is difficult due to the presence of over 50 described and many undescribed native species. Morphological differences between species are small, and there are no diagnosable species groups (with one exception: the Diaphorina amoena group). Here we define a second, putatively monophyletic species group, the Diaphorina albomaculata group, consisting of six Afrotropical species. In two of the species, it was observed that the immatures were tended by ants. One of the members of the D. albomaculata group is Diaphorina pfanderae Aléné and Burckhardt sp. nov., developing on Ozoroa pulcherrima (Anacardiaceae) in West Cameroon. Here, adults and immatures are described and diagnosed with illustrations. Diaphorina pfanderae differs from the other species of the D. albomaculata group in the fore wing pattern and details of the male and female terminalia as well as details of the chaetotaxy in immatures. Keys are provided for the identification of the adults and last-instar immatures of the species of the D. albomaculata group. Immatures of D. pfanderae showed a preference for young leaves, a characteristic shared by other psyllids. The species has always been associated with the three ant species Camponotus congolensis, C. flavomarginatus and Crematogaster sp. (Hymenoptera: Formicidae). The first two species often build soil shelters around the psyllid colonies situated on twigs, stems or leaves of O. pulcherrima. urn:lsid:zoobank.org:pub:4418BAB6-B6B7-459C-B75E-9CDC8971E054

A new species of Proceratophrys Miranda-Ribeiro, 1920 (Anura, Odontophrynidae) of the P. bigibbosa species group from Southern Brazil

Abstract The monophyletic Proceratophrys bigibbosa species group has a stable taxonomic history. Despite the increasing number of Proceratophrys described in the last decades, the P. bigibbosa group, for a long time, has consisted of four species distributed in south of South America; except for P. palustris that occurs in southeastern Brazil. Herein, based on concordant evidence of morphology and mtDNA barcoding, we describe a new species of Proceratophrys for specimens assigned to the P. bigibbosa group collected in Tibagi municipality, Paraná state, Brazil. The new species is diagnosed by its small size, snout rounded in dorsal view, palpebral ridge with small and rounded tubercles, small postocular swellings, presence of a line of small and round tubercles on dorso-lateral region of body, and dorsal region covered by small, sparse, and rounded tubercles. We also highlight the potential occurrence of the new species in other areas along the Campos Gerais of Paraná, given the strong association of the species with this vegetational formation in South Brazil.

Phylogeny and evolution of habitat preference in Goniurosaurus (Squamata: Eublepharidae) and their correlation with karst and granite-stream-adapted ecomorphologies in species groups from Vietnam

Abstract Maximum likelihood (ML) and Bayesian inference (BI) analyses using two mitochondrial (16S and cyt b) and two nuclear (CMOS and RAG1) genes and 103 specimens recovered the first phylogenies of all 23 extant species of Goniurosaurus. The analyses strongly supported the recognition of four monophyletic species groups with identical inter-specific relationships within the kuroiwae, lichtenfelderi, and yingdeensis groups but discordant topologies at some nodes within the luii group. Both analyses recovered a polyphyletic G. luii with respect to G. kadoorieorum, and owing to the lack of diagnostic characters in the latter, it is considered a junior synonym of G. luii. A stochastic character mapping analysis of karst versus non-karst habitat preference suggested that karstic landscapes may have played a major role in the evolution and diversification of Goniurosaurus. A karst habitat preference is marginally supported as the most probable ancestral condition for Goniurosaurus as well as for the kuroiwae, luii, and yingdeensis groups. However, a non-karst habitat preference is marginally supported as the most probable ancestral condition for the lichtenfelderi group. Multivariate and univariate ecomorphological analyses of the karst-adapted G. catbaensis, G. huuliensis, and G. luii of the luii group and the granite-stream-adapted G. lichtenfelderii of the lichtenfelderi group demonstrated that their markedly statistically different body shapes may be an adaptive response that contributes to habitat partitioning in areas of northern Vietnam where they are nearly sympatric.

THE VIOLETS OF THE BRAZILIAN SAVANNA: A REVISION OF THE POMBALIA LANATA COMPLEX (VIOLACEAE), WITH DESCRIPTIONS OF TWO NEW SPECIES

Pombalia Vand. (Violaceae) is represented in the Cerrado by a well-supported monophyletic group of species known as the Pombalia lanata complex, characterised by some unique vegetative and reproductive features within the genus. This group includes six species – Pombalia cristalina, P. insignis, P. lanata, P. poaya, P. strigoides and P. velutina – the first two of which are new to science. Pombalia lanata shows the widest geographical distribution throughout the Central Brazilian Plateau and the Espinhaço Range in Minas Gerais state, with a disjunction in Misiones Province, Argentina. Because most species in this group are narrow endemics, we evaluated the conservation status of all taxa. An identification key for the species, descriptions, illustrations, maps of geographical distribution and nomenclatural notes are also provided.

Phylogenetic partitioning of the third-largest vertebrate genus in the world, Cyrtodactylus Gray, 1827 (Reptilia; Squamata; Gekkonidae) and its relevance to taxonomy and conservation

The gekkonid genus Cyrtodactylus is the third most speciose vertebrate genus in the world, containing well over 300 species that collectively range from South Asia to Melanesia across some of the most diverse landscapes and imperiled habitats on the planet. A genus-wide phylogeny of the group has never been presented because researchers working on different groups were using different genetic markers to construct phylogenies that could not be integrated. We present here Maximum likelihood and Bayesian inference mitochondrial and mito-nuclear phylogenies incorporating of 310 species that include dozens of species that had never been included in a genus-wide analysis. Based on the mitochondrial phylogeny, we partition Cyrtodactylus into 31 well-supported monophyletic species groups which, if used as recommended herein, will increase the information content of future integrative taxonomic analyses that continue to add new species to this genus at an ever-increasing annual rate. Data presented here reiterate the outcome of several previous studies indicating that Cyrtodactylus comprises an unprecedented number of narrow-range endemics restricted to single mountain tops, small islands, or karst formations that still remain unprotected. This phylogeny can provide a platform for various comparative ecological studies that can be integrated with conservation management programs across the broad diversity of landscapes and habitats occupied by this genus. Additionally, these data indicate that the true number of Cyrtodactylus remains substantially underrepresented.

Phylogenetic partitioning of the third-largest vertebrate genus in the world, Cyrtodactylus Gray, 1827 (Reptilia; Squamata; Gekkonidae) and its relevance to taxonomy and conservation

The gekkonid genus Cyrtodactylus is the third most speciose vertebrate genus in the world, containing well over 300 species that collectively range from South Asia to Melanesia across some of the most diverse landscapes and imperiled habitats on the planet. A genus-wide phylogeny of the group has never been presented because researchers working on different groups were using different genetic markers to construct phylogenies that could not be integrated. We present here Maximum likelihood and Bayesian inference mitochondrial and mito-nuclear phylogenies incorporating of 310 species that include dozens of species that had never been included in a genus-wide analysis. Based on the mitochondrial phylogeny, we partition Cyrtodactylus into 31 well-supported monophyletic species groups which, if used as recommended herein, will increase the information content of future integrative taxonomic analyses that continue to add new species to this genus at an ever-increasing annual rate. Data presented here reiterate the outcome of several previous studies indicating that Cyrtodactylus comprises an unprecedented number of narrow-range endemics restricted to single mountain tops, small islands, or karst formations that still remain unprotected. This phylogeny can provide a platform for various comparative ecological studies that can be integrated with conservation management programs across the broad diversity of landscapes and habitats occupied by this genus. Additionally, these data indicate that the true number of Cyrtodactylus remains substantially underrepresented.

Unravelling taxonomic ambiguity of the Mastacembelidae in the Mekong Delta (Vietnam) through DNA barcoding and morphological approaches

Morphological-based species identification can be problematic for a comparative worldwide survey if taxonomic keys are limited and inconsistent, as illustrated in the family Mastacembelidae. This study combined DNA barcoding and morphological methods to test species identification of Mastacembelidae in the Mekong Delta with emphasis on taxonomic ambiguity of the precise identification of the fish locally known as chach bong. Fish specimens were collected from fishermen in different regions of the delta. Five presumed species within two genera were recorded. Samples were morphologically measured for morphometric and meristic traits. Representative samples of each species were sequenced at the cytochrome c oxidase subunit I (COI) gene. The number of dorsal fin spines and general morphological appearance are distinguishable among the five presumed species. However, morphometric measurements overlapped between Macrognathus semiocellatus and Macrognathus siamensis. K2P distances based on COI sequences among species were high, ranging from 12.4% to 18.7%. All individuals were separated into monophyletic groups of species, clustered into Mastacembelus and two Macrognathus lineages. Chach bong should be recognized as Mastacembelus favus and not Mastacembelus armatus as previously classified. No Mastacembelus armatus was recorded in the Mekong Delta. GenBank sequences of Mastacembelus armatus formed a sister relationship to Mastacembelus favus although both have the same range of number of dorsal fin spines and similar reticulated patterns on the body. Misidentification between these two species has been widely recorded in international databases of species taxonomy and DNA barcodes. Nonetheless, their genetic distance (12.4%) is higher than conspecific distances of samples from other regions, indicating the two species can be differentiated by DNA barcoding.

Acroeimeria lineri (McAllister, Upton, Freed, 1988) Paperna and Landsberg, 1989 in Mediterranean Geckos (Hemidactylus turcicus): Oocyst Morphometrics, Endogenous Developmental Stages, and Molecular Sequencing Support its Placement into Acroeimeria.

Between June 2016 and June 2019, we surveyed 62 Mediterranean geckos, Hemidactylus turcicus, from Abu Rawash, Giza, Egypt, for the presence of endoparasites. In June 2016, we found 3 individuals to be infected with Eimeria lineri. We studied the morphology and inner structures of its sporulated oocysts, and the locations of its intestinal endogenous stages. We also extracted genomic DNA from these sporulated oocysts and successfully sequenced a 632-bp fragment of the 18S rRNA gene. Phylogenetic analyses using this partial sequence allowed us to support previous studies that assigned E. lineri to the genus Acroeimeria. Our consensus sequence was used to query similar 18S rDNA sequences from GenBank, and 14 sequences were selected. The phylogenetic analysis inferred by maximum likelihood and Bayesian inference methods gave similar results, as both separated the sequences into 2 clades: (1) a monophyletic group of Goussia species (from fish); and (2) a strongly supported clade that separated 4 Choleoeimeria species from a polyphyletic group of species that clustered A. lineri with 3 other Acroeimeria species and 3 Eimeria species from lizards, including Eimeria tiliquae from Tiliqua rugosa (Gray, 1825), Eimeria tokayae from Gecko gecko (L., 1758), and Eimeria eutropidis from Eutropis macularia (Blyth, 1853). Our study supports the placement of E. lineri into the Acroeimeria and contributes additional life history information toward understanding the evolutionary origin of the Eimeria-like species that have sporocysts without Stieda bodies in their oocysts and that infect saurian reptiles. We also support the concept that several traits (morphological, endogenous, and gene sequences) are both necessary and important for authors to include when making generic reassignments within the eimeriid coccidia.

Phylogenetic analysis of the winter and southernmost scorpion genus Urophonius (Bothriuridae), with the description of two new Patagonian species

The first phylogenetic analysis of genus Urophonius is performed based on morphological characters. Three monophyletic species groups are recovered. Species of the granulatus species group and Urophonius mondacai have summer or spring activity patterns. The exochus and brachycentrus species groups form a monophyletic group with a winter activity pattern, which is so far unique in scorpions from temperate and cold areas. Additionally, two new Patagonian species of Urophonius are described, one from Argentina and one from Chile. Finally, we discuss the southernmost distributions of scorpions in continental Patagonia. We suggest that the southern limit of the group could be related not only with a decrease in temperature, but also with an increase of precipitation.

Phylogeny and species delimitation in Silene sect. Arenosae (Caryophyllaceae): a new section.

A putatively monophyletic group of annual Silene species is revised taxonomically and described as the new section S. sect. Arenosae. The species of this section were previously treated as a part of a widely circumscribed and polyphyletic S. sect. Rigidulae. Silene sect. Arenosae as circumscribed here consists of nine species. Members of the section show a predominantly E Mediterranean to SW Asian distribution pattern from Turkey southward to Egypt and eastward to Iran and Pakistan, although most of the species have a limited distribution range. The species of S. sect. Arenosae are characterized by narrowly lanceolate calyx teeth, which are often highly polymorphic, and lanceolate to oblanceolate (non-spathulate) basal leaves. The provided taxonomic revision is based on morphological characters and supported by phylogenetic analyses of two nuclear loci (nrITS and an intron of the RPB2 gene) and one chloroplast locus (the intron of the rps16 gene). The species descriptions are formalized using a novel implementation of the Prometheus Description Model.

Symposium 2: How adverse caregiving conditions affect offspring developmental trajectories: Evidence from longitudinal studies

The evolution of flight triggered the rise of pterygote insects, but secondary flightlessness has evolved numerous times and is often associated with reduced gene flow among populations and patterns of diversification. With 85 species most of which are wing reduced, the ground beetle genus Trechus in the European Alps may be one such example. Here, we reconstructed a molecular phylogeny using 72 of these species based on mitochondrial and nuclear DNA sequences as a basis for reconstructing their evolutionary history. We rearranged the species into 20 monophyletic species groups, of which five are novel and 15 were already established but with different species allocated. Wing measurements revealed a strong tendency for wing reduction but also variation within and among species, with the few fully-winged species distributed across multiple species groups containing also wing-reduced species. Using character mapping and phylogenetic independent contrasts, we found that neither distribution area, body size, pigmentation, elevational zone, nor hygrophily explained wing status in our sample. Assessing five completely sampled clades, we inferred that each of their ancestors had most likely already been wing reduced. We discuss putative scenarios explaining this pattern and the presence of wing polymorphism across the phylogeny. One plausible scenario would be an already wing-reduced last common ancestor of all Trechus species and multiple regains of full wing length via back mutation and/or hybridisation. Alternatively and possibly more likely, the ancestors were either fully winged, with subsequent rapid and repeated wing reduction explaining the current wing-status pattern, or polymorphic, with long-term polymorphism or reselection acting on standing genetic variation explaining the recent fully-winged species. Either way, Trechus ground beetles are a promising, taxonomically and ecologically diverse system for studying the evolution of flightlessness. Areas for future research include morphological assessment of flight muscles, functional analysis of flight capability, and exploration of the mechanistic and genetic bases of wing and flight evolution.

Extensive plastid-nuclear discordance in a recent radiation ofNicotianasectionSuaveolentes(Solanaceae)

AbstractNicotiana section Suaveolentes is the largest section of Nicotiana and is a monophyletic group of allotetraploid species. Most of the species are endemic to Australia, but three species occur on islands in the South Pacific as far east as French Polynesia and one species is native to Namibia. Here, we present phylogenetic results based on genome skimming, with near-complete taxon sampling and multiple accessions sampled for several species. These represent the first phylogenetic results for the section that include most recognized taxa, using wild-sourced material wherever possible. Despite known chromosome number and genome size changes in the section, there is little divergence in the ribosomal DNA operon (26S, 18.S and 5.8S plus associated spacers) and plastid genomes, with little to no taxonomic signal in plastome phylogenetic results and clear plastid-nuclear discordance. These results contrast with strong morphological differentiation (both floral and vegetative) between most of the core Australian taxa and obvious differences in ecological preferences. Together, these initial results portray Nicotiana section Suaveolentes as experiencing recent and ongoing radiation in the arid zone of Australia.

A new section, Lactifluus section Neotropicus (Russulaceae), and two new Lactifluus species from the Atlantic Forest, Brazil

Lactifluus is a monophyletic genus of ectomycorrhizal fungi with about 200 described species classified in four subgenera: L. subg. Gymnocarpus, L. subg. Lactariopsis, L. subg. Lactifluus, and L. subg. Pseudogymnocarpus. Currently L. subg. Lactariopsis is considered monophyletic with approximately 57 species described and classified in four sections: Albati, Edules, Lactariopsis, and Russulopsidei. There are few species of L. subg. Lactariopsis described from the Neotropical region, however local mycologists commonly collect specimens of this subgenus during their mycological surveys. The goals of the present study are to evaluate the phylogenetic and morphological relationships of the species from L. subg. Lactariopsis found in Brazil, to contribute to the knowledge of Lactifluus in Neotropical ecosystems by describing a new section in this subgenus and two new species from Brazil, and to document L. neotropicus as a new record from Brazil. Based on morphological and phylogenetic evidence we propose Lactifluus sect. Neotropicus as a new section and Lactifluus catarinensis and L. marielleae as two new species in this section. We provide a key to the species of L. sect. Neotropicus, which is shown to be a monophyletic group of Neotropical species within L. subg. Lactariopsis. The most striking characteristic of several species in L. subg. Lactariopsis is the secondary angiocarpic development, not present in the other subgenera. Species with a secondary veil can be found in two lineages that diversified more recently than the rest of the genus: L. sect. Lactariopsis and L. sect. Neotropicus. Species that show morphological affinities with the two new species in L. sect. Neotropicus described here are commonly found and we expect a greater diversity to be revealed of this section in the Neotropical region.