bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogenetic and phylogenetic diversification of the hooded staminode in Marantaceae
Authors: Pischtschan Elke , Ley Alexandra C. , Claßen-Bockhoff Regine 
Published: February 2019

AbstractThe flowers of Marantaceae are known for their unique pollination mechanism mediated by an explosive style movement. The mechanism is based on the highly modified elements of the inner androecial whorl, i.e., the single half‐fertile anther and the fleshy and hooded staminodes. We investigated 67 species across 24 genera to elucidate which parts of the hooded staminode are shared by all species, thus likely under strong selection pressure, and which are allowed to vary. We treated hooded staminodes as character syndromes and grouped them based on gross similarities. We identified characters underlying the similarity and investigated their diversity and developmental pathways. All hooded staminodes correspond in their general morphology, development and vascularisation, suggesting they are homologous. Variable proportions, differential growth and the formation of secondary structures result in a diversity of morphologies. The hooded staminodes can be grouped into ten distinct types. These morphological types are in accordance with the accepted clades of the family indicating their phylogenetic significance. The early diverging clades are characterised by stiff and elaborate staminode structures whereas in more distantly diverging clades simplified forms appear. We conclude that elaborate structures are not essential to maintain the pollination mechanism and thus have been reduced in the course of evolution.
Sectional rearrangement of arborescent clades of Croton (Euphorbiaceae) in South America: Evolution of arillate seeds and a new species, Croton domatifer
Authors: Riina Ricarda , van Ee Benjamin , Wiedenhoeft Alex C. , Cardozo Alfonso , Berry Paul E. 
Published: February 2019

AbstractMost of the arborescent Croton species in the New World were treated by Webster as belonging either to C. sect. Cyclostigma Griseb. or C. sect. Luntia (Neck. ex Raf.) G.L. Webster. The circumscription of C. sect. Cyclostigma has been treated recently. In this paper we focus on C. sect. Luntia, which was subdivided by Webster into two subsections, C. subsect. Matourenses and subsect. Cuneati. Using chloroplast trnL‐F and nuclear ITS DNA sequence data, morphology and a broader sampling of additional Croton lineages, we found that the two subsections are not closely related and form distinct monophyletic groups. Substantial morphological differences support the molecular data. A taxonomic recircumscription of the two subsections, elevated to sectional level, is proposed. A key and taxonomic revision, with new synonyms, is provided for C. sect. Cuneati; together with the description of a new species from the coastal mountains of Venezuela, Croton domatifer. The new species is the only one in the genus known to possess leaf domatia. We infer that species in the Cuneati clade have lost the typical Croton caruncle, and some of them have evolved a different, specialized type of aril. We hypothesize that the arillate seeds are an adaptation to dispersal by fish in the Orinoco and Amazon river basins.
Speciation genetics: Limits and promises
Authors: Karrenberg Sophie 
Published: February 2019

AbstractMany central questions on speciation genetics such as the nature of genetic changes involved and the role of selection in speciation have been under prolonged and intense debate. The development of massively parallel sequencing and increased cooperation among ecological, population and molecular geneticists, offer the promise to find answers to these questions. However, there currently is evidence for the involvement of many different factors and processes in speciation, with their relative importance unresolved. Processes implicated in speciation include not only geographic isolation and structural change through small‐effect mutations, but also regulatory mutations, copy number variation and chromosomal rearrangements, as well as scenarios of divergence‐with‐gene‐flow and evolution through genetic conflict. In this review, I summarize current views and persistent limitations in speciation genetics, explore two promising research approaches in this field and end with an overview on current and expected progress in plant speciation genetics.
A phylogenetic evaluation of Panicum sects. Agrostoidea, Megista, Prionitia and Tenera (Panicoideae, Poaceae): Two new genera, Stephostachys and Sorengia
Authors: Zuloaga Fernando O. , Scataglini M. Amalia , Morrone Osvaldo 
Published: February 2019

AbstractThe taxonomic features of species of Panicum, previously classified in Panicum subg. Agrostoidea and Phanopyrum including sects. Megista, Tenera, Prionitia and Agrostoidea, are reviewed and compared with subg. Panicum and other taxa of Paniceae. All taxa, previously considered in these subgenera and sections, are now included in the new genera Stephostachys and Sorengia, which are based on morphological and molecular characters. Stephostachys includes one species, S. mertensii (Roth) Zuloaga & Morrone, ranging from Mexico to Argentina, while Sorengia comprises seven species, S. anceps (Michx.) Zuloaga & Morrone, S. caricoides (Nees ex Trin.) Zuloaga & Morrone, Sorengia longifolia (Torr.) Zuloaga & Morrone S. petersonii (Hitchc. & Ekman) Zuloaga & Morrone, S. prionitis (Nees) Zuloaga & Morrone, S. stenodes (Griseb.) Zuloaga & Morrone, and S. tenera (Beyr. ex Trin.) Zuloaga & Morrone, distributed from the United States to Bolivia and Brazil. Affinities of the new genera with other genera of Paniceae are discussed. Lectotypes are designated for Panicum caricoides var. glabriusculum Döll, P. caricoides var. pilosum Döll, P. prionitis Nees, P. prionitis var. varium Kuntze, and P. stenodes Griseb.
Latin diagnoses: An unnecessary impediment — A response to Jørgensen
Authors: Figueiredo Estrela , Moore Gerry , Smith Gideon F. 
Published: February 2019

AbstractWe conclude that the arguments put forward by Jørgensen in his response to our recent proposal to abandon botanical Latin as the mandatory language in which to provide a description or diagnosis when a new species is described, in fact serve to confirm that this requirement must now be removed from the International Code of Botanical Nomenclature.
A molecular phylogeny and a new classification ofPyrola(Pyroleae, Ericaceae)
Authors: Liu Zhen-Wen , Zhou Jing , Liu En-De , Peng Hua 
Published: February 2019

AbstractThe northern temperate genus Pyrola L. is the largest and arguably the most taxonomically complex element in the tribe Pyroleae (Ericaceae). Here we present a molecular phylogenetic study with extensive sampling comprising 26 ingroup and 7 closely related taxa. The results, based on parsimony and Bayesian analyses of nuclear (ITS) and chloroplast (atpB‐rbcL, trnS‐trnG, trnL‐trnF) DNA sequences, add substantially to our understanding of relationships within this diverse group and call for taxonomic changes. Pyrola is confirmed as a monophyletic group with two redefined sections and six series: P. sect. Pyrola (P. ser. Pyrola, ser. Ellipticae and ser. Rugosae) and P. sect. Scotophylla (P. ser. Japonicae, ser. Scotophyllae and ser. Chloranthae). Members of each respective section and series share similar morphological traits and/or geographical distributions. For the potential hybrids P. media and P. faurieana, the maternal donor was identified by their close affinity to P. minor in the chloroplast trees whereas the paternal donor remained unclear.
Just what is a genus? Comparing levels of postzygotic isolation to test alternative taxonomic hypotheses in Orchidaceae subtribe Orchidinae
Authors: Scopece Giovanni , Cozzolino Salvatore , Bateman Richard M. 
Published: February 2019

AbstractAn exceptionally wide range of systematic data has been accumulated on subtribe Orchidinae, which dominates the European orchid flora. Despite (or perhaps because of) this wealth of information, delimitation of genera within the subtribe continues to prompt extensive debate among taxonomists. Here, we use the controversial genus Orchis s.l. as a case‐study to explore the broader issues that surround the definition and circumscription of genera, and suggest a new approach to selecting among competing formal classifications that focuses on the biological cohesion of the resulting taxa. Levels of postzygotic reproductive isolation, assessed as differential embryo mortality through extensive artificial crosses between species, are compared with three taxonomic treatments: a pre‐cladistic morphological classification permitting polyphyly; a cladistic classification generated by applying monophyly to Internal Transcribed Spacer sequences; and a 'post‐cladistic' classification that aimed to compromise between morphological and molecular differences and permitted paraphyly. The monophyletic cladistic classification is by far the most consistent with levels of postzygotic isolation through embryo mortality. Reproductive isolation, sequence divergence and morphological similarity can all usefully be quantitatively compared with formal classifications, though floral morphology in orchids offers a high risk of rapid co‐evolutionary divergence with pollinator guilds, often generating spurious monospecific 'genera'. Best practice in taxonomy reflects reciprocal illumination between key biological datasets and formal classifications, pursued in a rigorous framework of precise definitions of taxa and well‐founded evolutionary‐phylogenetic concepts.
The application of cophylogenic tools to gene sets
Authors: Baum Bernard R. , Johnson Douglas A. 
Published: February 2019

AbstractSeveral studies of host‐parasite evolution have used gene trees developed for each partner as a means to detect the influence of one on the evolution of the other, a process known as cophylogeny. We now extend this concept and present a process to test whether two genes or gene regions within the same species have coevolved in order to assess their further utility in the same phylogenetic analysis. The process entails well‐established methods; firstly based upon a given set of sequence data, inference of best‐fit evolutionary models and associated parameters through to gene tree building by maximum likelihood. This is followed by a "ParaFit" analysis of pairwise combination of genes or gene regions. The pairwise combinations that pass the test of cophylogeny may then be horizontally concatenated for phylogenetic inference of the set of taxa under study. The complete mathematical properties of this process presently remain unexplored; however, we demonstrate the utility of such an analysis prior to phylogenetic inference using examples from available datasets.
Graphis is two genera: A remarkable case of parallel evolution in lichenized Ascomycota
Authors: Plata Eimy Rivas , Hernández M. Jesús E. , Lücking Robert , Staiger Bettina , Kalb Klaus , Cáceres Marcela E.S. 
Published: February 2019

AbstractMolecular phylogenetic analysis of the mitochondrial small subunit and nuclear large subunit ribosomal DNA revealed that the lichen genus Graphis sensu Staiger represents two separate lineages. Graphis s.str. comprises the species of the G. scripta and G. subserpentina groups (‘Eugraphis’), as well as the G. striatula group sensu Lücking. For the segregate genus, the name Allographa Chevall. is available, and this genus includes the G. acharii, G. dussii, G. marginata, G. nuda, and G. symplecta groups. The separation of both lineages is supported by principal component analysis species ordination based on phenotype characters, although the G. dussii and G. subserpentina groups appear phenotypically intermediate. Species formerly placed in Hemithecium subg. Hemithecium sensu Staiger were shown to belong to at least four lineages, one nested within Graphis (H. implicatum), one within Allographa (H. chlorocarpum), one sister to Allographa (H. rufopallidum), and one nested within the Phaeographis clade (H. plicosum). Allographa is genetically close to the bulk of lirellate Graphidaceae (Diorygma, Glyphis, Pallidogramme, Phaeographis, Platygramme, Platythecium, Sarcographa, Thalloloma, Thecaria), whereas Graphis s.str. exhibits unique genetic apomorphies and takes a more isolated position.
Extensive gene flow blurs species boundaries among Veronica barrelieri, V. orchidea and V. spicata (Plantaginaceae) in southeastern Europe
Authors: Bardy Katharina E. , Schönswetter Peter , Schneeweiss Gerald M. , Fischer Manfred A. , Albach Dirk C. 
Published: February 2019

AbstractLittle is known about the contribution of interspecific hybridization, a frequent phenomenon in plants, to the high plant diversity in southeastern Europe, one of the continent’s diversity hot spots. A good system to study the relevance of hybridization for biodiversity in this region is Veronica subg. Pseudolysimachium sect. Pseudolysimachion (Plantaginaceae). Depending on the presumed frequency of hybridization, existing taxonomic concepts in this group range from distinguishing only morphological races without explicit taxonomic status to recognizing several species each with a series of intraspecific taxa. Using genetic (plastid sequences and AFLP fingerprints), ploidy‐level and morphometric data, three core groups, pertaining to the currently recognized species V. barrelieri, V. orchidea, and V. spicata, were identified. All three species are, however, connected by numerous and gradual genotypic transitions and show rampant discrepancies between genetic and morphometric‐taxonomic assignments. Complete homogenization of the three core groups is probably prevented by geographic isolation, ecological divergence and ploidy differences. Misinterpretation of hybrid swarms as separate taxa and the mosaic distribution of different indumentum types have led to a gross overestimation of taxonomic diversity of V. sect. Pseudolysimachion in southeastern Europe. Taxonomically, this might be accommodated by reducing V. barrelieri, V. orchidea and V. spicata to subspecific rank and abandoning recognition at least of those subspecies and varieties included in our study.
The generic concept of Lotononis (Crotalarieae, Fabaceae): Reinstatement of the genera Euchlora, Leobordea and Listia and the new genus Ezoloba
Authors: Boatwright James S. , Wink Michael , van Wyk Ben-Erik 
Published: February 2019

AbstractLotononis is a large and taxonomically complex genus of the tribe Crotalarieae, with the majority of its species occurring within southern Africa. In this study, sequence and morphological data of the rare Lotononis macrocarpa was added to existing data matrices for the Crotalarieae and these were re‐analyzed using both parsimony and model‐based (Bayesian) analyses. Molecular systematic data (nrITS and rbcL) indicated that Lotononis is polyphyletic, with Lotononis sect. Euchlora as sister to Bolusia and Crotalaria and with L. macrocarpa close to the ‘Cape’ group of the Crotalarieae. As a result, the genus Euchlora is here reinstated and the new genus Ezoloba is described herein to accommodate the anomalous L. macrocarpa. Ezoloba is distinct in its 5+5 anther configuration, exceptionally large fruit, paired stipules, minutely serrate bracts and the presence of bracteoles. Within the remaining species of Lotononis, both combined and separate analyses of the morphological and sequence datasets revealed three strongly supported clades corresponding largely to clades recovered in previous cladistic analyses based on morphological, chemical and cytological data. These are here recognised at the generic level as Lotononis s.str., Leobordea and Listia and the necessary new name combinations are formalised. Characters supporting these generic re‐alignments are discussed and a key to the 16 genera now recognized in the tribe Crotalarieae is presented.
Blastocaulon (Eriocaulaceae), a synonym of Paepalanthus: Morphological and molecular evidence
Authors: de Andrade Maria José Gomes , Giulietti Ana Maria , Harley Raymond Mervyn , van den Berg Cássio 
Published: February 2019

AbstractGeneric circumscription in Eriocaulaceae has been based primarily on one to few floral characters and phylogenetic relationships within the family have only recently been explored in detail. Here, we present a morphological and phylogenetic study of Blastocaulon and Paepalanthus ser. Leptocephali, based on individual and combined datasets of the psbA‐trnH plastid region and nuclear ITS. All results rejected the monophyly of Blastocaulon. Based on results and previous analyses, we propose the synonymization of Blastocaulon under Paepalanthus, the only morphological distinction between the two genera being the number of pollen‐sacs. Reduction of pollen‐sac number has occurred more than once in the evolution of Eriocaulaceae.
Who amends the International Code of Botanical Nomenclature? A response to Applequist & al. (2010)
Authors: Smith Gideon F. , Figueiredo Estrela , Moore Gerry 
Published: February 2019

AbstractWe maintain that a review of the way in which votes that can be cast to influence the amendment of the International Code of Botanical Nomenclature (ICBN) are allocated is overdue. Although there will no doubt be resistance to proposed changes that may emanate from such a review, a more representative system of vote allocation to herbaria, among other things, will considerably enhance the credibility and robustness of the voting system. A rebuttal addressing two criteria we suggest as examples of what could be used as part of a review to make the voting system more representative was recently published by Applequist & al. It is regrettable that in the face of unambiguous statistics that show the inadequacy of the current ICBN amendment voting system, the need for change is not embraced with due urgency. A fear of power sharing and decentralization may well be the root cause.
Genome scans reveal high levels of gene flow in HawaiianPittosporum
Authors: Bacon Christine D. , Allan Gerard J. , Zimmer Elizabeth A. , Wagner Warren L. 
Published: February 2019

AbstractSpecies radiations in the Hawaiian Islands have resulted in closely related yet morphologically and often ecologically distinct species, many of which have highly restricted distributions. Eleven species ofPittosporum, (Pittosporaceae) are recognized in the Hawaiian Islands, yet it remains unclear whether the morphological variation within HawaiianPittosporumis due to hybridization, genetic polymorphism, phenotypic plasticity, or some combination of these processes. In this study of HawaiianPittosporumwe used a genome‐wide approach employing 626 Amplified Fragment Length Polymorphisms (AFLPs) to test species boundaries and elucidate gene flow within and among species. Parsimony trees were constructed to identify clades of individuals that correspond to species, island affinity, and/or sexual system. Network analysis was used to identify the number of lineages in the dataset; results showed a lack of resolution due to reticulation. Based on Bayesian assignment tests, HawaiianPittosporumexhibited high levels of gene flow. The interspecific allelic exchange and reticulation caused non‐hierarchical relationships between species and a lack of reproductive isolation rendered species boundaries permeable. This study highlights the impact of hybridization on species persistence and conservation as well as on general patterns of Hawaiian biota.
Phylogenetic signal of orbicules at family level: Rubiaceae as case study
Authors: Verstraete Brecht , Groeninckx Inge , Smets Erik , Huysmans Suzy 
Published: February 2019

AbstractOrbicules are tiny a‐cellular sporopollenin structures that occur in the anthers of many angiosperms together with the pollen grains. Although their occurrence is common, little is known about their function and systematic usefulness. With regard to orbicules, Rubiaceae (Gentianales) are the most intensively studied plant family and therefore an ideal case to present the evolution and phylogenetic signal of orbicule characters at family level. The occurrence and morphology of orbicules was investigated in 64 species of Rubiaceae using scanning electron microscopy. Five relevant orbicule features (presence/absence, abundance, size, shape, ornamentation) were optimized onto a custom‐made phylogeny of the family. By optimizing the five orbicule characters some evolutionary trends can be observed. The previously suggested trend in angiosperms towards orbicule absence in more derived taxa is confirmed for Rubiaceae. Orbicules appear to have been independently lost at least nine times within the family, with two subsequent reversals. Small orbicules represent the plesiomorphic character state for the family. A trend from spherical towards irregular orbicules is observed, while ornamented orbicules occur only in derived lineages. Orbicule characters are constant at generic level and in most cases at tribal level, and therefore have potential for systematics. The presence of orbicules is correlated with the occurrence of a non‐amoeboid tapetum.
Erroneous identities ofPotamogetonhybrids corrected by molecular analysis of plants from type clones
Authors: Kaplan Zdenek , Fehrer Judith 
Published: February 2019

AbstractHybridization is one of the main sources of taxonomic complexity inPotamogeton. In spite of long and intensive research, the total hybrid diversity and distribution of many hybrids are still insufficiently known. Identities of two currently recognized hybrids were tested using molecular analyses of plants from the original clones growing at the type localities of their correct names. Additive characters in direct sequencing of the ITS region and the placement of cloned sequences in a Bayesian consensus tree were used to identify the exact identity of these hybrids.Potamogeton ×lanceolatifoliusis widely recognized as a hybridP. gramineus×P. polygonifolius. However, the molecular analyses and cytological investigation identified this Swedish hybrid asP. gramineus×P. nodosusalthoughP. nodosuscurrently does not occur in the whole of Scandinavia. This hybrid provides some insight into the former distribution area ofP. nodosusas affected by past climatic changes. The recently detectedP. ×vepsicuswas originally described asP. alpinus×P. natansbut the molecular investigation revealed that its correct identity isP. natans×P. praelongus. In both cases, the actual identities could hardly have been unequivocally deduced from the morphology of the hybrids. The existence of these hybrid combinations is here confirmed for the first time. The maternally inherited chloroplastrpl20-5'rps12sequences were used to identify the female parental species. The name “P. ×argutulus”, previously, but erroneously, used for a hybridP. gramineus×P. nodosus, is typified and reduced to the synonymy ofP. gramineus.
Nomenclature and typification of names of genera and subdivisions of genera in theCypereae(Cyperaceae): 3. Names in segregate genera ofCyperus
Authors: Reynders Marc , Huygh Wim , Larridon Isabel , Muasya A. Muthama , Govaerts Rafaël , Simpson David A. , Goetghebeur Paul A. 
Published: February 2019

AbstractRecent molecular studies reveal thatCyperus, the core genus ofCypereae(Cyperaceae), includes several segregate genera. This paper presents a survey of all published names of subdivisions of these segregate genera ofCyperus. It is the third paper in a series of papers on the nomenclature of names of genera and subdivisions of genera inCypereae. Most names of subdivisions of genera inCypereaewere published in Kyllinga, Mariscus and Pycreus. Types are indicated, being designated where needed, and names are evaluated for their priority and legitimacy. The complex taxonomy of these genera resulted in the accumulation of 79 subdivisional names of which 20 are not validly published and two are illegitimate.
Neotypifications of Linnaean names in Hybanthus (Violaceae)
Authors: de Paula-Souza Juliana 
Published: February 2019

AbstractCurrent studies in South American Violaceae detected the necessity of neotypes for Viola calceolaria L. (≡ Hybanthus calceolaria (L.) Oken) and Viola oppositifolia L. (≡ Hybanthus oppositifolius (L.) Taub.), names of species originally described in Loefling’s Iter Hispanicum, but without validly published names.