Showing papers in "Taxon in 2019"

The case for the continued use of the genus name Mimulus for all monkeyflowers

Abstract: Additional co-authors: Jannice Friedman, Dena L Grossenbacher, Liza M Holeski, Christopher T Ivey, Kathleen M Kay, Vanessa A Koelling, Nicholas J Kooyers, Courtney J Murren, Christopher D Muir, Thomas C Nelson, Megan L Peterson, Joshua R Puzey, Michael C Rotter, Jeffrey R Seemann, Jason P Sexton, Seema N Sheth, Matthew A Streisfeld, Andrea L Sweigart, Alex D Twyford, John H Willis, Kevin M Wright, Carrie A Wu, Yao-Wu Yuan

Generic classification of Amaryllidaceae tribe Hippeastreae

Abstract: A robust generic classification for Amaryllidaceae has remained elusive mainly due to the lack of unequivocal diagnostic characters, a consequence of highly canalized variation and a deeply reticulated evolutionary history. A consensus classification is proposed here, based on recent molecular phylogenetic studies, morphological and cytogenetic variation, and accounting for secondary criteria of classification, such as nomenclatural stability. Using the latest sutribal classification of Hippeastreae (Hippeastrinae and Traubiinae) as a foundation, we propose the recognition of six genera, namely Eremolirion gen. nov., Hippeastrum, Phycella s.l., Rhodolirium s.str., Traubia, and Zephyranthes s.l. A subgeneric classification is suggested for Hippeastrum and Zephyranthes to denote putative subclades. In Hippeastrum, we recognize H. subg. Hippeastrum and H. subg. Tocantinia. In Zephyranthes, Z. subg. Eithea, Z. subg. Habranthus, Z. subg. Myostemma (= core Rhodophiala clade), Z. subg. Neorhodophiala subg. nov., and Z. subg. Zephyranthes are recognized. Descriptions, synonymy, taxonomic keys, and new combinations are provided for each genus and subgenus.

Species delimitation in the genus Greenwayodendron based on morphological and genetic markers reveals new species

Abstract: Combining genetic and morphological markers is a powerful approach for species delimitation, much needed in tropical species complexes. Greenwayodendron (Annonaceae) is a widespread genus of trees distributed from West to East African rainforests. Two species and four infra-specific taxa are currently recognized. However, preliminary genetic studies and morphological observations suggested the occurrence of additional species, undescribed to date. We tested species delimitation within Greenwayodendron by combining morphological and population genetics data. First, a visual inspection of about a thousand specimens suggested the existence of seven morphogroups: four of them occur in Central Africa and overlap in Gabon while three others are allopatric, occurring respectively in West Africa, East Africa, and the islands of Sao Tome and Principe. Their morphological differentiation was confirmed by analysis of 27 morphological characters coded from 233 herbarium specimens. Second, after genotyping 800 samples at eight nuclear microsatellites, Bayesian clustering analyses (STRUCTURE) identified four genetic clusters corresponding to the well-sampled morphogroups but failed to separate the three remaining morphogroups represented by few samples. However, we show that this is an inherent limit of the STRUCTURE algorithm, whereas factorial correspondence analysis (FCA) and pairwise FST and RST measures confirmed the genetic differentiation of all morphogroups. We considered that a clear genetic differentiation occurring between sympatric populations advocates for recognizing distinct species following the biological species concept. Our analyses highlight that the current taxonomic treatment of Greenwayodendron underestimates the total number of species. We identified two new species and support separation at the rank of species of two varieties (G. suaveolens subsp. suaveolens var. gabonica, G. suaveolens subsp. suaveolens var. suaveolens) and one subspecies (G. suaveolens subsp. usambaricum). The taxonomic status of specimens collected in Sao Tome and Principe remains inconclusive, partly due to the limited fertile material available. Our study highlights the strength of combining morphological and population genetics data for discovering new taxa. Guidelines for using genetic clustering approaches in species delimitation are provided.

A multi‐character analysis of Struthiopteris leads to the rescue of Spicantopsis (Blechnaceae, Polypodiopsida)

Abstract: The family Blechnaceae is a moderately sized leptosporangiate fern lineage, with 24 genera and around 250 species. Struthiopteris accommodates small to medium-sized, dimorphic, pinnate species. It is composed of six northern species: S. spicant is distributed in western parts of Europe and North America; S. fallax is endemic to Iceland; S. niponica, S. amabilis and S. castanea are endemic to Japan, and S. hancockii occurs in Japan and Taiwan. Due to the lack of a global review and to its highly interesting geographical distribution, this genus merits further study to clarify its taxonomy, species relationships, and distributional pattern. The present study aims to achieve the following goals: (a) identify and describe morphological characters supporting the taxonomy of Struthiopteris; (b) reconstruct a complete phylogeny for the genus; (c) study the biogeographical history of Struthiopteris at a global scale. The morphological study involved the observation of characters ranging from rhizome scales to spores over 164 individuals. Phylogenies were constructed applying ML and BI techniques over 51 newly produced sequences of three chloroplast markers (rbcL, trnL-trnF, psbA-trnH), using the species Blechnidium melanopus and Brainea insignis as closest relatives. For the molecular dating and historical biogeography analyses, we estimated and compared ancestral ranges under several models. Most of the morphological characters led us to discern two groups of species: the S. spicant group (S. spicant, S. fallax, and S. castanea) and the S. niponica group (the remaining species). In our molecular phylogeny, the supposed sister genus Blechnidium always appeared as nested within Struthiopteris, rendering this genus non-monophyletic. The two groups identified by the morphology appeared as monophyletic clades within Struthiopteris, with the clade S. spicant more closely related to Blechnidium than to the clade S. niponica. For all these reasons, we propose to rescue the now-disused genus Spicantopsis for the species belonging to the S. niponica group: indeed, this genus was created c. 100 years ago to reunite the same species S. amabilis, S. niponica, and S. hancockii. Our results suggest that all members of this group of genera (Blechnidium, Struthiopteris, Spicantopsis) emerged in East Asia about 85 mya, at a time when Japan was still part of the mainland. It appears that, for most of their history, the members of these genera have been confined to East Asia, with one dispersal to the Americas by an ancestor within Struthiopteris s.str., and additional dispersals to India and the Philippines by Blechnidium melanopus.

Reestablishment of Protium cordatum (Burseraceae) based on integrative taxonomy

Abstract: Species delimitation remains a challenge worldwide, but especially in biodiversity hotspots such as the Amazon. Here, we use an integrative taxonomic approach that combines data from morphology, phylogenomics, and leaf spectroscopy to clarify the species limits within the Protium heptaphyllum species complex, which includes subsp. cordatum, subsp. heptaphyllum, and subsp. ulei. Molecular phylogeny indicates that populations of subsp. cordatum do not belong to the P. heptaphyllum clade, while morphology and near‐infrared spectroscopy data provide additional support for the recognition of a separate taxon. Protium cordatum (Burseraceae) is reinstated at species rank and described in detail. As circumscribed here, P. cordatum is endemic to white‐sand savannas located in the Faro and Tucuruí Districts, Pará State, Brazil, whereas P. heptaphyllum is a dominant and widespread plant lineage found in Amazonia, the Cerrado, and the Brazilian Atlantic Forest. We present an identification key to P. cordatum and closely related lineages and a detailed taxonomic description of P. cordatum, including habitat and distribution, a list and images of diagnostic features. This study demonstrates the importance of using multiple tools to characterize and distinguish plant species in highly diverse tropical regions.

Phylogenetic reconstruction of the genus Tephrocactus (Cactaceae) based on molecular, morphological, and cytogenetical data

Abstract: Fil: Las Penas, Maria Laura. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto Multidisciplinario de Biologia Vegetal. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Instituto Multidisciplinario de Biologia Vegetal; Argentina. Universidad Nacional de Cordoba; Argentina

Genetic and morphological data reveal new insights into the taxonomy of Campanula versicolor s.l. (Campanulaceae)

Abstract: Campanula versicolor is a constituent of the Campanula pyramidalis complex, distributed in the central and southern Balkan Peninsula with a small disjunct range in SE Italy. The taxonomy of the broadly defined C. versicolor was controversial in the past due to high morphological variability of the populations across the range. We used microsatellite DNA data along with morphometric analyses on an extensive population sampling covering the entire range to reconstruct the relationships among populations of the intricate C. versicolor s.l. Based on the results three distinct entities can be distinguished, circumscribed here on the subspecies level, with newly established combinations: C. versicolor subsp. versicolor, C. versicolor subsp. korabensis and C. versicolor subsp. tenorei. We propose a new taxonomic treatment of C. versicolor s.l. with description, distribution and habitat data for each of the subspecies and a key for their identification.

Resolving intergeneric relationships in the aervoid clade and the backbone of Ptilotus (Amaranthaceae): Evidence from whole plastid genomes and morphology

Abstract: The informally named “aervoid clade” in Amaranthaceae includes ~134 species in five genera: Ptilotus (~120 spp.), Aerva (11 spp.) and the monotypic Nothosaerva, Omegandra, and Kelita. The relationships of the small aervoid genera to the large genus Ptilotus, and relationships between major clades within Ptilotus, are poorly resolved. The aims of this study were to: (1) elucidate relationships between genera and within Ptilotus using a phylogenomic approach; (2) identify morphological characters within each genus to help delimit generic boundaries; and (3) provide an updated taxonomic framework for the aervoids. A well-supported coding DNA sequence (CDS) phylogeny was constructed for 36 aervoid and 5 outgroup species based on 69 gene sequences derived from assembled whole-plastid genomes. The CDS tree was used to constrain relationships on a larger phylogeny based on Sanger-sequenced ITS and matK for 135 taxa, comprising near-comprehensive sampling within the aervoids. Both datasets were analysed using maximum likelihood and Bayesian inference. Morphological characters were assessed from herbarium specimens. Our study demonstrates that Aerva is polyphyletic; this is resolved by reinstating Ouret and erecting a new genus, Paraerva. Kelita is found to be deeply nested within Ptilotus and is formally synonymised. The well-resolved phylogeny of Ptilotus presented here will inform future studies in biogeography and character evolution. A taxonomic treatment is provided for all aervoid genera, and new combinations are made.

Molecular phylogeny of the large South American genus Eriosyce (Notocacteae, Cactaceae): Generic delimitation and proposed changes in infrageneric and species ranks

Abstract: Eriosyce is one of most species‐rich genera within Notocacteae (Cactaceae) harboring a variety of stem and flower morphologies, and fruits with basal abscission. The lack of a well‐sampled molecular phylogeny contributes to the current taxonomic instability of the genus, where its circumscription and infrageneric classification has been questioned. Specimens of Eriosyce (63 taxa) plus 19 outgroups were analyzed through sequencing three plastid noncoding introns (rpl32‐trnL, trnL‐trnF, trnH‐psbA), one plastid gene (ycf1), and one nuclear gene (PHYC). Individual markers and concatenated matrices were analyzed using maximum likelihood and Bayesian approaches. Phylogenetic analyses strongly support the monophyly of Eriosyce s.l. Furthermore, seven clades within Eriosyce s.l. were defined based on supported branches, although one of them was weakly supported. Our results suggest that some past taxonomic proposals have low phylogenetic support and should no longer be used, e.g., based on their scattered positions in the phylogenetic reconstruction, several infraspecific taxa appear unrelated to the typical form of the species in which they had been placed. We present a phylogeny‐informed infrageneric classification of the genus Eriosyce, and new combinations are proposed to update the nomenclature of species and sections.

A novel phylogenetic infrageneric classification of Baccharis (Asteraceae: Astereae), a highly diversified American genus

Abstract: We present the hitherto most comprehensive phylogenetic hypothesis for Baccharis. Our results confirm that subtribe Baccharidinae is a monogeneric group and support a broad circumscription of Baccharis as monophyletic with the inclusion of all genera that have been previously segregated from it (Baccharidastrum, Baccharidiopsis, Heterothalamulopsis, Heterothalamus, Lanugothamnus). We provide comprehensive lists of accepted and synonymized infrageneric taxa. Seven main lineages are recognized, which we treat as subgenera. Subgenera Baccharis and Molina roughly match previous circumscriptions, while subgenera Pteronioides and Stephananthus are merged with Molina. In total, we propose that Baccharis comprises 440 species classified into 7 subgenera and 47 sections, while 22 sections are considered synonyms. The phylogeny provided constitutes the basis for further exploration of the evolutionary processes that have allowed the group to attain its wide geographic distribution, morphological variation, variable sexual reproductive strategies, and complex chemical contents.

Molecular-based assessments of tribal and generic limits and relationships in Rubiaceae (Gentianales): Polyphyly of Pomazoteae and paraphyly of Ophiorrhizeae and Ophiorrhiza

Abstract: Circumscriptions of the Australasian tribes Ophiorrhizeae and Pomazoteae (Rubiaceae) as well as their generic relationships and limits have long remained unsettled. These tribes were originally del ...

Phylogeny of the Neotropical legume genera Zygia and Marmaroxylon and close relatives

Abstract: The Neotropical legume genera Zygia and Marmaroxylon have traditionally been considered closely related and are sometimes treated as congeners. They have been referred to the mimosoid tribe Ingeae ...

RAD sequencing rejects a long‐distance disjunction in Stellaria (Caryophyllaceae) and yields support for a new southern Rocky Mountains endemic

Abstract: Whereas the eastern North American–eastern Asian floristic connection represents one of the most widely studied biogeographical relationships in flowering plant evolution, connections between western North America and Asia have been comparatively rarely investigated, especially through genetic approaches. Stellaria irrigua is one of several plants that has been treated as an exceptionally dramatic example of a disjunction between floristically similar, high alpine biotas of the southern Rocky Mountains and south-central Siberia. We here employ numerous new field collections and ddRADseq data to test the hypothesis that S. irrigua—a species that has been known for over 180 years—represents a long-distance disjunction between the southern Rocky Mountains and central Asia. Extensive fieldwork, review and perusal of herbarium materials, and phylogenomic analyses indicate that S. irrigua is broadly distributed across an amphi-Beringian arc extending from southern and central Asia, east through Beringia, and south throughout mountainous regions of western North America. Sampled Asian populations formed two clades, and North American individuals all formed a clade embedded within this broader Asian lineage. Stellaria irrigua is, however, rendered non-monophyletic by a lineage that is embedded within the North American populations and is ecologically and morphologically distinctive from S. irrigua. The identity of this newly recognized lineage, which was in prior works attributed to S. irrigua, has been confused since plants of the former were first collected in the San Juan Mountains of Colorado in the late 1800s under Arenaria and Alsine. We provide a new name for this taxon, Stellaria sanjuanensis, a charismatic starwort of dry alpine scree slopes of the southern Rocky Mountains. Additionally, two lectotypes are designated, one holotype and one isotype are identified, and two new synonymies are proposed, to help stabilize the taxonomy and nomenclature of this long-confused species complex. A key to the starworts of the southern Rocky Mountains is also provided, and Stellaria alsine is reported as new to the region.

IAPT chromosome data 31

Abstract: Karol Marhold (ed.), Jaromír Kučera (ed.), Camila Aguiar-Melo, Erton Mendonça de Almeida, Lânia Isis Ferreira Alves, Tatyana V. An’kova, Fernanda Bered, Kallyne Bonifácio, Luana Carvalho, Franco E. Chiarini, Joel M.P. Cordeiro, Mihai Costea, Julio Rubén Daviña, Aleksandr L. Ebel, Allan Falconi-Souto, Cattleya M.P. Felix, Leonardo P. Felix, Aveliano Fernández, Miguel Ángel García, Ignacio García-Ruiz, André dos Santos Bragança Gil, Marcelo Guerra, Luiza Domingues Hirsch, Ana Isabel Honfi, Eliane Kaltchuk-Santos, Sandra Knapp, Rohit Kumar, Vandna Kumari, Juliana Lovo, Reinaldo F.P. Lucena, Enoque Medeiros-Neto, Ana Paula Moraes, Rodrigo Garcia Silva Nascimento, José Achilles Lima Neves, Felipe Nollet, Regina Célia de Oliveira, Andrés Orejuela, Marisa Toniolo Pozzobon, Anna Verena Reutemann, André Rodolfo de Oliveira Ribeiro, Gabriel Hugo Rua, Angeline M.S. Santos, Anádria Stéphanie da Silva, Rosemere Silva, Ronimeire Torres da Silva, Vijay Kumar Singhal, Tatiana T. Souza-Chies, Saša Stefanović, José Francisco Montenegro Valls, Cassiano A.D. Welker & Elena Yu. Zykova

Phylogenetic and morphometric analysis of Plantago section Coronopus (Plantaginaceae)

Abstract: Plantago sect. Coronopus contains our two focal species (P. coronopus L., P. crassifolia Forssk.), both with an overall conspicuous bi‐hemispheric distribution range (Mediterranean and Middle Eastern regions in the Northern Hemisphere and South Africa in the Southern Hemisphere). We have evaluated up to 27 morphological characters from 96 herbarium specimens representing five out of seven species of that section that are currently recognised using principal coordinate analysis, linear discriminant analyses, agglomerative clustering, and classification tree analyses, in order to test the current taxonomic concepts of our two focal species. Furthermore, we used 54 individuals representing six out of those seven species of P. sect. Coronopus to construct molecular phylogenetic hypotheses by sequencing nuclear ribosomal DNA from the internal transcribed spacer region (ITS), the plastid trnL‐F region, the plastid intergenic spacer region trnH‐psbA and adopting maximum likelihood and Bayesian inference analyses. In the Northern Hemisphere, an Irano‐Arabian clade initially identified as P. coronopus and shown as distinct in both morphological and phylogenetical terms fits a wider circumscription of P. crypsoides Boiss. due to lack of the prominent short and thick inflorescence scape following Boissier's description. The morphological differences between P. crassifolia from the Mediterranean region and P. crassifolia from South Africa (often named P. carnosa Lam.) were marginal, yet the molecular phylogenetic analyses of both nuclear and plastid markers clearly separated these evolutionary entities. Therefore, we re‐instated the name P. carnosa as the correct name for South African P. crassifolia. Plantago carnosa differs from P. crassifolia by the combination of having stronger woody rootstocks, which are more often branched, by broader leaves (≥1.6 mm wide) and the fact that specimens more often turn brown when dried. Our dataset provides the best sampled phylogenetic hypothesis for P. sect. (and subg.) Coronopus to date, and reveals discordance between nuclear and plastid genealogies within P. sect. Maritima, which requires further investigation.

Origin and evolution of Atriplex (Amaranthaceae s.l.) in the Americas: Unexpected insights from South American species

Abstract: Fil: Brignone, Nicolas Fernando. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Botanica Darwinion. Academia Nacional de Ciencias Exactas, Fisicas y Naturales. Instituto de Botanica Darwinion; Argentina

How photographs can be a complement of herbarium vouchers: A proposal of standardization

Abstract: Challenges in the collection of vouchers, either because of the physical properties of the material (species difficult to collect or to press, e.g., palms, cycads, toxic plants, and cacti) or because drying may have a negative effect on taxonomic characters (e.g., colour), recommend the use of photographs to complement herbarium specimens. In a series of cases (enumerated in the present contribution), however, it may be impossible to collect material and, thus, photographs may be the only option to document the presence of a plant in a given locality. We propose in this paper some guidelines for the standardization of photographs intended for deposit in herbaria.