33 research outputs found

    Some aspects of the moss population development on the Svalbard glaciers

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    Glaciers are rather unusual habitat for mosses, but sometimes they can be suitable for some species due to presence of sufficient moisture and cryoconite substrate in the ablation zone. To date, moss populations were found only on a few glaciers in Alaska, Iceland and Svalbard. An origin and development of moss cushions on ice (so called "glacier mice") are still unclear. In this study, some aspects of the moss population development were explored on ice of the Svalbard glaciers – Bertilbreen (Billefjorden) and Austre Grnfjordbreen (Grnfjorden) in 2012 and 2013. On Bertilbreen, populations of Hygrohypnella polaris (Lindb.) Ignatov & Ignatova and Schistidium abrupticostatum (Bryhn) Ignatova & H.H. Blom were found for the first time. Due to putative morphological features, identification of S. abrupticostatum was confirmed by com-paring ITS1-2 nrDNA sequence data to BLAST searches (megablast). The results indicated a genetic heterogeneity of the population. Although visually moss-free, examination of cryoconite sediments revealed development of new individuals of S. abrupticostatum from filamentous structures consisting of caulonema and rhizoids. The developmental stages of young plants were revealed. Therefore, besides fragmen-tation of existing cushions, cryoconite sediments provided a source of new moss cush-ions in glacier populations. Additionally a few plants of Pohlia cf. wahlenbergii (F. Weber & D. Mohr) Andrews and a gametophyte fragment of Philonotis sp. were found in aggregation of cryoconite. Presence of Paludella squarrosa (Hedw.) Brid. reported for Bertilbreen has not been confirmed. On Austre Grnfjordbreen Bryum cryophilum Mrtensson, Sanionia uncinata (Hedw.) Loeske were found invading into some Hygrohypnella polaris cushions. Each moss polster on ice represents a separate mini-ecosystem that includes successive colonization events

    Taxonomical rearrangements of Solenostomataceae (Marchantiophyta) with description of a new family Endogemmataceae based on trnL-F cpDNA analysis

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    The results of trnL-F cpDNA analysis of the suborder Jungermanniineae allow to re-evaluate relations and taxonomy of the morphologically distinctive species Solenostoma caespiticium. A new monotypic family Endogemmataceae is described. The new combination Endogemma caespiticia is made. Provisionally, the genus Nardia is placed in Gymnomitriaceae.

    Stolonicaulon: A Section-Puzzle within Marsupella (Gymnomitriaceae, Marchantiophyta)

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    Marsupella sect. Stolonicaulon is not speciose and is a commonly neglected section within the genus, which currently includes three species with somewhat similar morphologies (wiry shoots with distanced leaves) and distributions in the mountains of tropical and subtropical regions (SE (Southeast) Asia, the Venezuelan Andes, and the high mountains of SE Brazil). After studying materials that were found to be dissimilar to the “traditional” Marsupella that were collected in the last decade by the authors of this article, it was found that these plants belong to three new-for-science species, and all of these species should be included in Marsupella sect. Stolonicaulon. The newly described species have expanded the boundaries of morphological variability, not only for the section itself, but also for the genus based on two findings: (1) the leaves of Marsupella sect. Stolonicaulon can be either appressed and entire or spaced and deeply divided (thus, the plants could occasionally be similar to Cephaloziella or Anastrophyllum); (2) some species of the section possess regular underleaf production. The first discovery of regular underleaves in Marsupella, as noted in two of the three newly described taxa, is the main morphological novelty described in this paper. The development of regular underleaves is a presumable relict character that brings Marsupella closer to Nardia, which was recently transferred to the Gymnomitriaceae and occupies an isolated position within its own subfamily, Nardioideae

    Exploring the impact of fossil constraints on the divergence time estimates of derived liverworts

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    In this study, we evaluate the impact of fossil assignments and different models of calibration on divergence time estimates carried out as Bayesian analyses. Estimated ages from preceding studies and liverwort inclusions from Baltic amber are used as constraints on a molecular phylogeny of Cephaloziineae (Jungermanniopsida) obtained from sequences of two chloroplast coding regions: rbcL and psbA. In total, the comparison of 12 different analyses demonstrates that an increased reliability of the chronograms is linked to the number of fossils assigned and to the accuracy of their assignments. Inclusion of fossil constraints leads to older ages of most crown groups, but has no influence on lineage through time plots suggesting a nearly constant accumulation of diversity since the origin of Cephaloziineae in the early to Middle Jurassic. Our results provide a note of caution regarding the interpretation of chronograms derived from DNA sequence variation of extant species based on a single calibration point and/or low accuracy of the assignment of fossils to nodes in the phylogeny

    The Current Diversity and Distribution of the Simple Thalloid Genus <i>Apopellia</i> (Marchantiophyta): Evidence from an Integrative Taxonomic Study

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    An integrative study of expanded sampling of Apopellia species, including the topotype of Apopellia megaspora, made it possible to clarify the taxonomic position and distribution of the species of the genus. The ITS1-2 and trnL-F sequence data were obtained for 36 molecularly tested specimens, including the topotype Apopellia megaspora, that together with data previously deposited in GenBank, support the treatment of Apopellia as a separate genus and A. alpicola as a distinct species, as well as radically change the idea on the distribution of the species of the genus. It is shown that A. megaspora is an American-Asian species with single records in Europe, whereas A. alpicola is a West-American-Eurasian species widespread in western North America and occurring scattered in Eurasia. Both species occur in the mountains of western North America and south Siberia. A. endiviifolia is widespread in Europe, scattered in Asia and so far not confirmed for America. The expanded sampling of Apopellia spp. allows us to clarify the morphological features of the species of the genus, and microphotographs illustrate the more-important morphological features

    Blepharostoma trichophyllum S.L. (Marchantiophyta): The Complex of Sibling Species and Hybrids

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    Blepharostoma trichophyllum was found to be a species collectiva formed by several strongly genetically different species. The taxonomic diversity in the group is the possible result of radiation in early stages; then, these taxa likely survived for a long time in similar environmental conditions, which resulted in stasis. Presently, the existing taxa are similar one to another and may be morphologically distinguished with difficulties. The most taxonomically valuable morphological characteristics include oil bodies and cells in the leaf segment features. The most diverse genotypes (the vast majority of which are treated here as distinct species) were found in amphi-Pacific Asia, which may reflect the evolutionary history of the genus or may be the consequence of more profound sampling in the macro-region in comparison with other parts of the Holarctic

    Hidden Diversity within Tetralophozia filiformis (Marchantiophyta, Anastrophyllaceae) in East Asia

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    Tetralophozia filiformis s.l. is known from a number of localities mostly in amphi-oceanic areas in Northern Hemisphere, including Atlantic Europe, amphi-Pacific Asia, South Siberia, and western North America. The newly obtained collections of this &lsquo;species&rsquo; show strong variation in morphology of the taxon across amphi-Pacific Asia although connected by some &lsquo;intergrading&rsquo; modifications. This implies the genetic diversity within this unit earlier recognized as a single taxon. Authors used molecular-genetic, morphological, and chorological methods to understand if the geographically correlated morphological variation also correlates with genetic differences and if it is possible to distinguish some additional taxa within the series of specimens originating from the various areas in amphi-Pacific Asia. It was found that Tetralophozia filiformis is a complex of at least three morphologically similar species, including one long forgotten name (Chandonanthus pusillus) that should be reinstated as separate species and one taxon (Tetralophozia sibirica) that should be described as new. Tetralophozia filiformis and Chandonanthus pusillus are lectotypified, and the new combination is provided for the latter. The three accepted taxa distinctly differ one from another in distribution patterns, preferable climate characteristics, and genetic distances, besides minor differentiations in morphology. The main morphological distinguishing features are the leaf cell size, height of undivided part in leaf lamina, and leaf dentation characteristics. Taking into account the robust correlation between the climate-based and molecular-genetic-based clusters, one more (fourth) taxon could be probably segregated from Tetralophozia filiformis
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