Liverwort Genus Research Articles

Evidence for Rampant Homoplasy in the Phylogeny of the Epiphyllous Liverwort Genus <I>Cololejeunea</I> (Lejeuneaceae)

Abstract Rampant homoplasy can be a major challenge in the classification of land plants that have limited morphological differences and/or ecological diversity, such as liverworts and mosses. Here we present the first comprehensive molecular phylogeny of the derived liverwort genus Cololejeunea and its close relatives. We used three markers (trnL—F, rbcL, and nrITS) and 116 accessions representing the geographic range as well as the morphological diversity of this predominantly epiphyllous genus. The molecular data support three major lineages: Colura, Myriocoleopsis, and Cololejeunea. Myriocoleopsis species were resolved in a clade with Cololejeunea minutissima. Aphanolejeunea and Chondriolejeunea were both resolved as putative monophyletic groups, and nested in the Cololejeunea clade. Cololejeunea angustiflora was found to be sister to the clade comprising the remaining Cololejeunea species. Currently accepted subgenera of Cololejeunea were paraphyletic or polyphyletic. Six out of 30 species with multi...

Riella bialataTrab. (Riellaceae, Marchantiophyta): A New Addition to the European Liverwort Flora

Riella (Riellaceae, Sphaerocarpales) is a genus of aquatic liverworts with a disjunct worldwide distribution in areas of seasonal Mediterranean-type climates. Its centre of diversity is located in the Mediterranean basin, where about half the species number of the genus is concentrated. In the course of a worldwide revision of the genus Riella, plants from a monoicous species with wingless, not papillose and smooth involucres were found in two distant Iberian localities. These plants showed a geminate dorsal wing, unlike the single wing occurring in the remaining species of the genus. This character unambiguously assigns these populations to R. bialata, a species known to date from a single collection in its Algerian type locality. Riella bialata is thus reported as new to Europe. Fresh materials enabled detailed morphological analyses, and the Iberian materials are extensively described and illustrated herein.

Chemosystematics of the Thai Liverwort Cheilolejeunea (Marchantiophyta, Lejeuneaceae)

Members of the liverwort genus Cheilolejeunea, on the basis of chemical data, have been divided into striatane- (I), trifarane- (II) and δ-lactone- (III) chemotypes. In this paper the sesquiterpenoids occurring in C. ceylanica from Thailand are described and the chemosystematics of Cheilolejeunea species are explored. Species belonging to type I produce striatane-type sesquiterpenoids, which have been found in many species of Lejeuneaceae and thus are considered to be one of the significant chemical markers of this family. However, to the best of our knowledge, the trifarane-type is not detected in any other liverworts. The lactone-type species produce chiroptical δ-lactones, with a milky odor.

Phylogeny and systematic position of Mesoptychia (Lindb.) A. Evans

A phylogenetic analysis of the leafy liverwort genus Mesoptychia (incl. Leiocolea and Hattoriella), using two chloroplast markers, rbcL and rps4, was performed to clarify the circumscription of the genus and to establish its systematic position within the Jungermanniales. Ten species and one variety of Mesoptychia (out of a total of 17 accepted specific names), together with 85 species from 57 genera representing different lineages of Jungermanniales, were sampled. The results support the monophyly of Mesoptychia and its inclusion within the Jungermanniaceae, which itself forms a clade with the Delavayellaceae. Gymnocolea borealis, previously treated under Leiocolea (= Mesoptychia), is nested in the Anastrophyllaceae. The synonymy of Hattoriella with Mesoptychia is phylogenetically confirmed. Four major clades are identified within Mesoptychia and their circumscriptions and distinguishing morphological features are discussed.

Striking autapomorphic evolution in Physotheca J.J.Engel & Gradst. (Marchantiophyta: Lophocoleaceae) blurred its actual relationships with Leptoscyphus Mitt.

The taxonomic status and phylogenetic position of the monotypic liverwort genus Physotheca J.J.Engel & Gradst., including P. autoica J.J.Engel & Gradst. endemic to Ecuador, are inferred from phylogenetic analyses of two cpDNA loci. The results indicate that the genus is nested within Leptoscyphus and the new combination, L. autoicus (J.J.Engel & Gradst.) Vanderp. & Gradst., is made. This indicates, along with an increasing body of evidence, that extreme morphological transformations can obscure the phylogenetic signal present in morphological data.

Tramps, narrow endemics and morphologically cryptic species in the epiphyllous liverwort Diplasiolejeunea

Diplasiolejeunea is a pantropical, epiphytic genus of leafy liverworts that occurs from the lowlands to more than 4000m altitude. Phylogenetic analyses of a molecular dataset consisting of three markers (nuclear ribosomal ITS region, plastidic trnL-F region and rbcL gene) and 122 accessions (plus two outgroups, Colura and Cololejeunea) indicate that the evolutionary diversity of Diplasiolejeunea is underestimated by current morphology-based classification. Four morphologically semi-cryptic species have been recovered. The molecular phylogenies support a deep split into a Neotropical and a Paleotropical clade, the latter structured into Australasian, Asian and Afromadacascan lineages. Presented results confirm the ranges of two pantropical species (D. cavifolia, D. rudolphiana), provide evidence for dispersal from the Neotropics into the Paleotropics, indicate speciation along altitudinal gradients and demonstrate extensive morphological homoplasy. We propose a revised supraspecific classification of Diplasiolejeunea into a predominantly Paleotropical subgenus Physolejeunea and predominantly Neotropical subgenera Austrolejeuneopsis and Diplasiolejeunea, the former containing mainly epiphytic species, the latter mainly epiphylls. Several clades are supported by combinations of morphological character states, and could be assigned to sections at some later point. This is the first comprehensive phylogeny of a largely epiphyllous genus of liverworts.

Two lectotypifications in British and Irish Herbertus

The liverwort genus Herbertus has been the focus of morphological and molecular research at the Royal Botanic Garden Edinburgh over the past few years, and using the novel technique of DNA barcodin...

The leafy liverwort Frullania (Jungermanniopsida) in the Cretaceous amber forest of Myanmar

Examination of two pieces of amber from the mid-Cretaceous of Myanmar revealed seven inclusions of leafy liverworts that we assign to the extinct Frullania cretacea Hentschel et al. 2009. These inclusions show a suite of characters that were not visible in the type specimen of F. cretacea. The new gametophytes consistently display rectangular to ovate underleaves that have two long-ciliate apical teeth in addition to 0–2 blunt lateral teeth. A narrow stylus is present on at least some leaves. The lobules usually form water sacs that are 1.2–2.3 times longer than wide, and are arranged at some distance from the stem. The observed combination of character states is not present in extant crown group lineages of Frullania. A syninclusion in one of the amber pieces is interpreted as a detached gynoecium of a second Cretaceous Frullania species and is described as F. baerlocheri, sp. nov. The subgynoecial underleaves of the syninclusion are suborbicular in shape, and allow for a separation of this species from F. cretacea. The described amber inclusions are the oldest representatives of an extant genus of leafy liverworts known so far.

Checklist of the Liverworts and Hornworts of New Caledonia1

The present checklist of the liverworts and hornworts of New Caledonia is a sequel to the recent catalogue of the mosses and accepts 464 species and 18 infraspecific taxa, in 104 genera and 39 families. In addition, 32 species are doubtful records of New Caledonia and 52 species are excluded. The hepatic flora of New Caledonia is more similar to that of Indomalesia than of Australasia, which may be explained by the predominantly tropical climate of New Caledonia. The composition of the flora is considered the result of a long history of dispersal and speciation events since 37 Ma. Endemism of liverworts and hornworts of New Caledonia is between 13% (confirmed endemics, treated in recent revision or monographs) and 39% (confirmed and potential endemics). The latter figure is the same as for mosses. One genus of liverworts, Meinungeria (Lepidoziaceae), is endemic to New Caledonia. Cheilolejeunea xanthocarpa, Mastigolejeunea indica and Microlejeunea lunulatiloba are reported as new to New Caledonia. The new name Cololejeunea aurantia (Tixier) Thouvenot comb. nov. (for Jovetastella aurantia Tixier) is proposed. Mastigobryum integristipulum Steph. ex Paris and Mastigobryum luxurians Steph. ex Paris are new synonyms of Bazzania vittata (Gottsche) Trevis., Chiloscyphus longifissus Steph. ex Paris is reduced to a synonym of Heteroscyphus grandiflorus (Steph.) Hürl. and Eulejeunea aloba Steph. ex Paris is referred to Lejeunea alobifolia HA. Mill.

Evolution of sexual systems, dispersal strategies and habitat selection in the liverwort genus Radula

• Shifts in sexual systems are among the most common and important transitions in plants and are correlated with a suite of life-history traits. The evolution of sexual systems and their relationships to gametophyte size, sexual and asexual reproduction, and epiphytism are examined here in the liverwort genus Radula. • The sequence of trait acquisition and the phylogenetic correlations between those traits was investigated using comparative methods. • Shifts in sexual systems recurrently occurred from dioecy to monoecy within facultative epiphyte lineages. Production of specialized asexual gemmae was correlated to neither dioecy nor strict epiphytism. • The significant correlations among life-history traits related to sexual systems and habitat conditions suggest the existence of evolutionary trade-offs. Obligate epiphytes do not produce gemmae more frequently than facultative epiphytes and disperse by whole gametophyte fragments, presumably to avoid the sensitive protonemal stage in a habitat prone to rapid changes in moisture availability. As dispersal ranges correlate with diaspore size, this reinforces the notion that epiphytes experience strong dispersal limitations. Our results thus provide the evolutionary complement to metapopulation, metacommunity and experimental studies demonstrating trade-offs between dispersal distance, establishment ability, and life-history strategy, which may be central to the evolution of reproductive strategies in bryophytes.

Chemosystematics of Porella (Marchantiophyta, Porellaceae)

The taxonomy of the liverwort genus Porella based on plant morphology has been regarded as difficult. Recent DNA-based studies have brought new insights into the systematics of these liverworts and have uncovered some novel relationships that allowed the resolution of controversial treatments based on morphology. One of the outstanding features of these plants, in addition to their form, is their chemical composition, which is characterized by great diversity of secondary metabolites. In this paper the sesqui- and diterpenoids occurring in Porella species are described and their chemosystematic relevance is explored. On the basis of chemical data, the Porella species have been divided into six chemotypes: the drimane- (I), sacculatane- (II), pinguisane-sacculatane- (III), guaiane-germacrane- (IV), pinguisane- (V) and africane- (VI) types. Species belonging to type I are characterized by their hot taste, whereas the other chemotypes are comprised of non-pungent species. Consideration of recent DNA data shows striking correlations between molecular groups and their terpenoid chemistry. The chemical data suggest that the P. vernicosa complex (chemotype I) deserves recognition as a separate section of Porella and that terpenoids are important chemosystematic markers in the family Porellaceae.

On the morphology, systematics and phylogeny of Noteroclada (Noterocladaceae, Marchantiophyta)

Noteroclada Taylor ex Hook. & Wilson has long been recognized as a unique leafy taxon having affinities to the north temperate, simple thalloid liverwort genus, Pellia Raddi. Although a suite of diagnostic characters clearly separate it from Fossombronia Raddi and other leafy, anacrogynous taxa, considerable confusion regarding its identity exists in historical treatments. There are unresolved questions in regards to the extent and significance of morphological variation within the genus, the number of species that should be recognized, the geographic range that it occupies and its position in liverwort phylogeny. Morphological, experimental and molecular techniques are employed to address these questions. These studies show that there are two forms of perennating tubers, which are geographically partitioned, that plants are always monoicous, that sporophytes are enclosed by a shoot calyptra and Fossombronia-like caulocalyx and that sporeling ontogeny is different from that of Pellia. Molecular analyses show some genetic variation within Noteroclada, but both morphological and molecular data support the recognition of but a single species, N. confluens Taylor ex Hook. & Wilson. It is confirmed that there are no reliable specimens of Noteroclada from Africa, Australasia or the Kerguelen sector and that the genus has two centers of distribution in Latin America, with disjunct populations in the Falkland Islands, South Georgia, Tristan da Cunha and Gough Island. Significant ontogenetic differences between Noteroclada and Pellia support their placement in separate monogeneric families of the Pelliales.

Phylogeny of the leafy liverwort Ptilidium: Cryptic speciation and shared haplotypes between the Northern and Southern Hemispheres

The small, phylogenetically isolated liverwort genus Ptilidium has been regarded as of cool-Gondwanic origin with the bipolar, terrestrial Ptilidium ciliare giving rise to the Northern Hemisphere epiphytes Ptilidium pulcherrimum and Ptilidium californicum. This hypothesis is examined using a dataset including three chloroplast DNA regions from 134 Ptilidium accessions and one accession each of its closest relatives Trichocoleopsis and Neotrichocolea. Maximum likelihood and parsimony analyses point to a close relationship between P. ciliare and P. pulcherrimum, whereas P. californicum is placed sister to the remainder of the genus, separated by a long branch. Haplotype analysis and our phylogeny indicate the presence of Southern Hemisphere haplotypes of P. ciliare in the Northern Hemisphere, and shared haplotypes of P. ciliare and P. pulcherrimum between Europe and North America. Based on our findings, we reject the Gondwana-scenario and propose recent long distance dispersal as an explanation for the bipolar disjunct range. Ptilidium ciliare is resolved as paraphyletic with P. pulcherrimum nested within it. An isolated Ptilidium lineage with the morphology of P. ciliare from the Himalaya region likely represents a hitherto unrecognized cryptic species. Ptilidium pulcherrimum splits into a Japanese clade and a clade with accessions from Europe and North America.

New insights in the evolution of the liverwort family Aneuraceae (Metzgeriales, Marchantiophyta), with emphasis on the genus Lobatiriccardia

AbstractPhylogenetic analyses using two fast evolving plastid markers (rps4, trnL‐F) reveal the occurrence of the Australasiatic liverwort genus Lobatiriccardia in the Neotropics. Two new species, Lobatiriccardia oberwinkleri and L. verdoornioides are reported from Ecuador. Phylogenetic reconstructions support Lobatiriccardia and Aneura as monophyletic sister groups and do not place Verdoornia as the first branching Aneuracean taxon but rather sister to Aneura and Lobatiriccardia, which is consistent with mycothallus development in Aneuraceae. Subsequently, Aneuraceae, as treated here, include Aneura, Lobati‐ riccardia, Riccardia, and Verdoornia. Although high levels of genetic structure can be observed among members of the Aneura pinguis complex, current species delimitations are questionable, and detailed analyses of cryptic speciation and biogeographic patterns are needed to understand the evolution of Aneura, with particular attention paid to the non‐photosynthetic species Aneura mirabilis. Ancestral state reconstructions suggest an evolutionary trend of female gametangia, and subsequently the sporophyte, moving from a central position on the dorsal side of the thallus (Verdoornia) to a marginal position between thallus lobes (Lobatiriccardia) to a more ventral (quasi latero‐ventral) position under the thallus margin (Aneura).

The ghosts of Gondwana and Laurasia in modern liverwort distributions

Recent advances in phylogenetics and, in particular, molecular dating, indicate that transoceanic dispersal has played an important role in shaping plant and animal distributions, obscuring any effect of tectonic history. Taxonomic sampling in biogeographic studies is, however, systematically biased towards vertebrates and higher plants and the possibility remains that a much stronger signature of ancient vicariance might be evident among other organisms, particularly among basal land plants. Here, an explicit Bayesian model-based approach was used to investigate global-scale biogeographic patterns among liverwort genera and to determine whether the patterns identified are consistent with the expectations of vicariance or dispersal scenarios. The distribution of each genus was mapped onto the phylograms describing the floristic affinities among areas in order to define the synapomorphic transitions supporting the observed groupings. The probabilities of change in a branch were calculated by implementing the Markov model of BayesTraits. The consistent ambiguity in ancestral state reconstructions returned by the unconstrained, two-rate model indicated that the overall signal in the data was weak, leading us to test the performance of competing, explicit models. The analyses resolved clades of geographic areas that are mostly consistent with the kingdoms traditionally identified for plants and animals, but with strikingly lower rates of endemism. The major split observed in the phylograms is into almost entirely Laurasian and Gondwanan clades. Other patterns recovered by the analyses, including Wallace's line and the South Atlantic Disjunction, have also traditionally been interpreted in terms of vicariance. These observations contrast with the idea that, in spore-dispersed organisms like bryophytes and pteridophytes, dispersal obscures evidence of vicariance. However, some discrepancies between the liverwort trees and expectations from a continental drift scenario were observed, such as the sister-group relationship of the Australian and New Zealand floras, which is supported by the co-occurrence of many genera, often endemic to these two areas. Together with an interpretation of the results within a phylogenetic context, our analyses suggest that patterns, which are at first sight consistent with an ancient vicariance hypothesis, may, in fact, conceal a complex mixture of relictual distributions and more recent, asymmetrical dispersal events. Our results provide a framework for testing specific evolutionary hypotheses concerning the extremely low levels of endemism in bryophytes and in particular, the significance of dispersal and cryptic diversification.

Molecular, phytochemical and morphological characterization of the liverwort genus Radula in Portugal (mainland, Madeira, Azores)

Relationships of the eight species of the liverwort genus Radula occurring in Portugal (mainland, the Madeira and Azores archipelagos), including the Macaronesian endemics R. jonesii and R. wichurae, were evaluated based on molecular, phytochemical and morphological–anatomical data. Maximum parsimony and Bayesian analyses were performed with sequences from three plastid DNA markers (trnS GGA-rps4 spacer, rps4 gene, trnL UAA intron), volatile oil compounds, as well as qualitative morphological–anatomical characters. In addition, the molecular data were subjected to maximum likelihood analysis. The eight taxa, R. aquilegia, R. carringtonii, R. complanata, R. holtii, R. jonesii, R. lindenbergiana, R. nudicaulis and R. wichurae, can be clearly distinguished from each other, either by molecular data alone or by combination of characters from all three data sets. Radula aquilegia is monophyletic according to the molecular data, but shows considerable, yet undescribed intraspecific morphological and phytochemical variability. Recognition of R. complanata and R. lindenbergiana as separate species, previously based solely on the paroecious vs. dioecious sexual condition, is moderately supported by the molecular phylogenetic analyses and strongly supported by the phytochemical data. The Radula species, narrowly distributed in Macaronesia and Atlantic Europe, probably have two different origins. For Radula holtii and R. nudicaulis, connections with Radula species from the Neotropics are indicated. The other species, among them the two Macaronesian endemics, are closely related with the R. complanata/R. lindenbergiana complex, which is widely distributed in the northern hemisphere.

Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats

New structural, nutritional, and stable carbon isotope data may resolve a long-standing mystery-the biological affinities of the fossil Prototaxites, the largest organism on land during the Late Silurian to Late Devonian (420-370 Ma). The tree trunk-shaped specimens, of varying dimensions but consistent tubular anatomy, first formed prior to vascular plant dominance. Hence, Prototaxites has been proposed to represent giant algae, fungi, or lichens, despite incompatible biochemical and anatomical observations. Our comparative analyses instead indicate that Prototaxites formed from partially degraded, wind-, gravity-, or water-rolled mats of mixotrophic liverworts having fungal and cyanobacterial associates, much like the modern liverwort genus Marchantia. We propose that the fossil body is largely derived from abundant, highly degradation-resistant, tubular rhizoids of marchantioid liverworts, intermixed with tubular microbial elements. Our concept explains previously puzzling fossil features and is consistent with evidence for liverworts and microbial associates in Ordovician-Devonian deposits, extensive ancient and modern marchantioid mats, and modern associations of liverworts with cyanobacteria and diverse types of fungi. Our interpretation indicates that liverworts were important components of Devonian ecosystems, that some macrofossils and microfossils previously attributed to "nematophytes" actually represent remains of ancient liverworts, and that mixotrophy and microbial associations were features of early land plants.

The taxonomy of the leafy liverwort genus Leptoscyphus (Lophocoleaceae) revisited

AbstractA revised classification of the liverwort genus Leptoscyphus (Lophocoleaceae) is presented on the basis of previous phylogenetic analyses as well as morphological examination of recent plant material and type specimens. The three subgenera that have traditionally been recognized based on morphological grounds, namely Leptoscyphus subg. Anomylia, L. subg. Physoscyphus, and L. subg. Leptoscyphus, are well retrieved by the phylogeny. Two new subgenera, L. subg. Spinoscyphus and L. subg. Australoleptoscyphus, are created for L. cleefii and L. spectabilis and the southern South Hemisphere species, respectively. Three new species, namely L. gradsteinii, L. lambinonii, and L. sotiauxii, are described here based on molecular and morphological evidence. The new combination L. porphyrius subsp. azoricus is made. Lectotypes are designated for Chiloscyphus australis, C. huidobroanus, Jungermannia amphibolia, J. pallidovirens, J. physocalyx, Lophocolea belmorana, L. diversifolia, L. excipulata, and Mylia azorica.

New England liverworts for the general public Mary SG. Lincoln . 2008. Liverworts of New England: A guide for the amateur naturalist. Memoirs of the New York Botanical Garden 99: 1–161. The New York Botanical Garden Press. Bronx, NY. [ISBN 978-0-89327-478-8]. Price US$45. Available from: www.nybgpress.org.

Popular identification guides to bryophytes are not at all common, although their numbers are increasing given the ease of capturing decent images with digital cameras. This book is the first of its kind for North America in that it includes many color photographs and treats all species of liverworts found in a multistate region. I do not know Mary S. G. Lincoln, but I suspect that as an amateur bryologist herself, this book was born out of a labor of love. As stated in the introduction, the book is ‘‘a nontechnical introduction to the liverworts and hornworts of New England.’’ The descriptions of species ‘‘emphasize characters that can be seen with a strong hand lens or a dissecting microscope.’’ Though aimed squarely at the beginner, all species of liverworts and hornworts currently or historically known for New England (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont) are included. I noted only the omission of Pedinophyllum interruptum known from Connecticut and Massachusetts. The hardcover is richly illustrated with attractive photographs of liverworts. While not specifically designed as a field guide, the duplication of the main ‘‘illustrated key to hornworts and liverworts’’ inside the front cover is convenient for field use. Sections preceding the main treatments provide a brief history of regional hepaticology, describe the New England landscape, give an overview of the distributions compiled and explain basic morphology and life cycle characteristics. Given the growing interest in bryophyte conservation, the paragraph on rare and endangered species of liverworts is misleading. It includes the following statement (p. 7): ‘‘Because liverworts are so infrequently studied, no one can really say that a particular species is rare or endangered, either worldwide or in a particular area.’’ The statement is later contradicted in the treatment of species where some are described as ‘‘rare.’’ There are three appendices: a traditional dichotomous key to 24 ‘‘common and easily identified’’ species; a list of ‘‘leafy liverwort genera arranged by size’’ and a list of ‘‘liverworts characteristic of specialized habitats.’’ A glossary of 90 terms, a bibliography and an index to scientific names are included. The main body of the book (pp. 12–142) consists of 15 sections (A–O), each a logical group identified by the two-paged ‘‘illustrated key.’’ For example, section A presents ‘‘complex thalloid liverworts with elevated receptacles,’’ and section I ‘‘leafy liverworts with lobed leaves and succubous insertion.’’ Each section begins with a key diagram to

RANGE DISJUNCTIONS, SPECIATION, AND MORPHOLOGICAL TRANSFORMATION RATES IN THE LIVERWORT GENUSLEPTOSCYPHUS

Bryophytes and angiosperms exhibit similar intercontinental disjunct distributions that have traditionally been explained by continental drift. Such disjunct distributions are, however, typically observed at the species level in bryophytes, whereas they occur at much higher taxonomic level in angiosperms. The corollary of this observation is that morphological evolution in bryophytes is exceedingly slow. These hypotheses can now be explicitly tested with the advent of molecular dating. In this article, we show that the trans-Atlantic disjunctions observed in the mostly tropical liverwort genus Leptoscyphus date back to 5.5 Myr, thus largely postdating the opening of the South Atlantic. The temporal calibration of the phylogeny allows us to estimate for the first time the absolute timing of morphological evolution in bryophytes. The time frame necessary for shifts to occur between character states was estimated on average at ca. 4.05+/-1.86 Myr. As opposed to the traditional view that bryophyte evolution has been triggered by episodic shifts in habitat conditions, our analyses furthermore suggest that morphological and molecular divergence gradually accumulated in the genus, which contrasts with the rapid diversification documented in some tropical trees.