97 research outputs found

    Ascogrammitis lehnertii (Polypodiaceae): a new and dominant understory-species from a diverse community of grammitid ferns in the Andes of Ecuador

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    In the scope of pantropical studies aimed at understanding how the diversity of grammitid ferns (Polypodiaceae) has evolved and is maintained, we studied a diverse grammitid community in treeline elfin forests in eight study plots of 400 m2 each at 3200 m on Cerro Toledo, Loja, southern Ecuador.Werecorded a total of 7986 individuals of 16 grammitid species. Ascogrammitis lehnertii is here described as a newspecies.We also recorded Mycopteris leucosticta, a species previously believed to be restricted to the Choc®o region of Ecuador. We found that the grammitid species were segregated by habitat into trunk-base and trunk specialists, which suggests that species coexistence in these diverse epiphytic communities is at least partly linked to habitat segregation. Ascogrammitis lehnertii and M. leucosticta were the second and third most abundant species, respectively, and both were mostly trunk-base species. The new species A. lehnertii differs from its congeners by the combination of its relatively broad lamina, (2–)3–4 cmwide, fertile leaves bearing 2mmlong reddish setae in and near the sori, and by bearing proliferous roots from which new plants emerge. Phylogenetic analyses of atpß, rbcL, rps4, trnG-trnR, andtrnL-trnFDNAmolecular sequences, usingmaximum likelihood, place A. lehnertii as sister to A. cuencana with strong support. Despite previous intensive collection efforts in Loja for the past 30 yr, all but one of the collections of this new species were made in the last three years. The discovery of A. lehnertii and the new record of M. leucosticta highlight the patchy distribution of some species in the Andes and the value of surveying

    Alansmia , a new genus of grammitid ferns (Polypodiaceae) segregated from Terpsichore

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    Alansmia, a new genus of grammitid ferns is described and combinations are made for the 26 species known to belong to it. Alansmia is supported by five morphological synapomorphies: setae present on the rhizomes, cells of the rhizome scales turgid, both surfaces of the rhizome scales ciliate, laminae membranaceous, and sporangial capsules setose. Other diagnostic characters include pendent fronds with indeterminate growth, concolorous, orange to castaneous rhizome scales with ciliate or sometimes glandular margins, hydathodes often cretaceous, and setae simple, paired or stellate. The group also exhibits the uncommon characteristic of producing both trilete and apparently monolete spores, sometimes on the same plant. New combinations are made for Alansmia alfaroi, A. bradeana, A. canescens, A. concinna, A. contacta, A. cultrata, A. dependens, A. diaphana, A. elastica, A. glandulifera, A. heteromorpha, A. immixta, A. kirkii, A. lanigera, A. laxa, A. longa, A. monosora, A. reclinata, A. semilunaris, A. senilis, A. smithii, A. spathulata, A. stella var. stella, A. stella var. flava, A. turrialbae, A. variabilis, A. xanthotrichia. Lectotypifications are made for Alansmia concina, A. variabilis, Polypodium ciliare, P. flexile, and P. ovalescens. The genus is named in honor of pteridologist Alan R. Smit

    The relationship between chlorophyllous spores and mycorrhizal associations in ferns: evidence from an evolutionary approach

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    Premise: Approximately 14% of all fern species have physiologically active chlorophyllous spores that are much more short-lived than the more common and dormant achlorophyllous spores. Most chlorophyllous-spored species (70%) are epiphytes and account for almost 37% of all epiphytic ferns. Chlorophyllous-spored ferns are also overrepresented among fern species in habitats with waterlogged soils, of which nearly 60% have chlorophyllous spores. Ferns in these disparate habitat types also have a low incidence of mycorrhizal associations. We therefore hypothesized that autotrophic chlorophyllous spores represent an adaptation of ferns to habitats with scarce mycorrhizal associations. Methods: We evaluated the coevolution of chlorophyllous spores and mycorrhizal associations in ferns and their relation to habitat type using phylogenetic comparative methods. Results: Although we did not find support for the coevolution of spore type and mycorrhizal associations, we did find that chlorophyllous spores and the absence of mycorrhizal associations have coevolved with epiphytic and waterlogged habitats. Transition rates to epiphytic and waterlogged habitats were significantly higher in species with chlorophyllous spores compared to achlorophyllous lineages. Conclusions: Spore type and mycorrhizal associations appear to play important roles in the radiation of ferns into different habitat types. Future work should focus on clarifying the functional significance of these associations. Keywords: arbuscular mycorrhizae; chlorophyllous spores; correlated evolution; dark septate endophytes; epiphytes; grammitid; green spores; pteridophyte

    The Color of Childhood: The Role of the Child/Human Binary in the Production of Anti-Black Racism

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    The binary between the figure of the child and the fully human being is invoked with regularity in analyses of race, yet its centrality to the conception of race has never been fully explored. For most commentators, the figure of the child operates as a metaphoric or rhetorical trope, a non-essential strategic tool in the perpetuation of White supremacy. As I show in the following, the child/human binary does not present a contingent or merely rhetorical construction but, rather, a central feature of racialization. Where Black peoples are situated as objects of violence it is often precisely because Blackness has been identified with childhood and childhood is historically identified as the archetypal site of naturalized violence and servitude. I proceed by offering a historical account of how Black peoples came to inherit the subordination and dehumanization of European childhood and how White youth were subsequently spared through their partial categorization as adults

    Target Sequence Capture of Nuclear-Encoded Genes for Phylogenetic Analysis in Ferns

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    Premise of the Study Until recently, most phylogenetic studies of ferns were based on chloroplast genes. Evolutionary inferences based on these data can be incomplete because the characters are from a single linkage group and are uniparentally inherited. These limitations are particularly acute in studies of hybridization, which is prevalent in ferns; fern hybrids are common and ferns are able to hybridize across highly diverged lineages, up to 60 million years since divergence in one documented case. However, it not yet clear what effect such hybridization has on fern evolution, in part due to a paucity of available biparentally inherited (nuclear‐encoded) markers. Methods We designed oligonucleotide baits to capture 25 targeted, low‐copy nuclear markers from a sample of 24 species spanning extant fern diversity. Results Most loci were successfully sequenced from most accessions. Although the baits were designed from exon (transcript) data, we successfully captured intron sequences that should be useful for more focused phylogenetic studies. We present phylogenetic analyses of the new target sequence capture data and integrate these into a previous transcript‐based data set. Discussion We make our bait sequences available to the community as a resource for further studies of fern phylogeny

    Two New Species of Pleopeltis (Polypodiaceae) from Andean South America

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    Volume: 97Start Page: 107End Page: 11

    Typification and Identity of Adiantum tetragonum (Pteridaceae)

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    Volume: 95Start Page: 89End Page: 9

    Developing an INTO-wide Professional Development Program for University Partners

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    At INTO North America’s first partners’ conference in Washington, DC in October of 2017, one of the topics that generated broad interest among partner institutions was how to create opportunities to share best practices for faculty members teaching international students. Now that academic year 2017-18 has come to a close, it is time to revisit this issue and bring the partners together to discuss how our INTO Centers and their Academic leadership and instructors can play a role in this important aspect of faculty development. Because of their disciplinary training and often their own personal experiences, center instructors are uniquely positioned to design and deliver educational programs in partnership with the offices on campuses that provide pedagogical development opportunities for faculty members (Centers for Teaching and Learning, Teaching Excellence, etc.). Creating a faculty development program that is a collaboration between INTO’s Centers, center instructors, university faculty and universities’ Centers for Teaching and Learning addresses a significant need on partner campuses and adds to INTO’s reputation as an innovative leader in the area of international student recruitment and education. In addition, this program would raise the visibility of INTO Centers on partner campuses and further integrate them into the core of their universities. It also reinforces the practical value of attendance at future partner conferences. For university partners, such a program could help to address an important issue using existing resources at little to no additional cost. One initial step will be to ask attendees what is currently happening on their campuses with respect to faculty development. It would be helpful if attendees would review resources on their campuses before the conference so that they can share resources at the meeting. The panelists also seek to gauge the interest of center and academic directors on this topic and if they find sufficient interest, they can work together to develop a fuller proposal that will be presented to INTO and at least 2-3 partners universities interested in piloting the project. The group will explore convening a meeting of center leads and the Directors of Centers for Teaching and Learning on the pilot campuses and ask them to develop a flexible curriculum that could be easily adapted to the needs and culture of each campus
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