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Typification of Leontodon taraxacum L. (≡ Taraxacum officinale F.H. Wigg.) and the generic name Taraxacum: A review and a new typification proposal
Abstract
The previous typification of Leontodon taraxacum L. (≡ Taraxacum officinale F.H. Wigg.) and hence of the generic name Taraxacum is analysed. It is shown that the typification and consequent nomenclatural and interpretation changes have been almost totally ignored by the botanical public and therefore have become a source of ambiguity or confusion, and that the previous lectotype is in serious conflict with the protologue. A new lectotype is designated that is in accordance with the protologue and corresponds to the currently generally adopted reasonably broad interpretation of Taraxacum officinale as a name of an aggregate of agamospermous and sexual common dandelions. The new lectotype is “Dens leonis latiore folio Bauh., In Lusatia, Bohemia, Dania, J. Burser vi.37 (UPS). In order to retain the broad-sense interpretation of the name, the authors do not recommend subsequent epitypification of the name.
... sect. Taraxacum (commonly also called Taraxacum officinale Wigg., see Kirschner & Štěpánek 2011). Dandelions show geographic parthenogenesis where the distribution of apomictic lineages exceeds the distribution of sexually reproducing dandelions towards northern regions. ...
... In the regions without sexual common dandelions, local populations consist of few to numerous distinct apomictic lineages, morphologically and genetically recognizable entities, sometimes referred to as microspecies, under binomials. Hundreds of microspecies within the T.officinale group have been described in Europe (Kirschner & Štěpánek 2011).These apomictic dandelion lineages are often widespread with a distribution that extends from western to eastern Europe, and from the southern Central Europe to Northern Europe. The distribution pattern in the sect. ...
... These crosses produce triploid offspring and some of these are functionally apomicts and can be founder individuals of new apomictic lineages (Tas & Van Dijk 1999). In Europe, hundreds of distinct apomictic lineages which are sometimes referred to as microspecies, have been described (Kirschner & Štěpánek 2011). Here we used the apomictic lineage T. officinale hemicyclum, for brevity hereafter referred to as T. hemicyclum, which was collected in Northeast Finland in spring 2013. ...
... (following Kirschner & Štěpánek, 2011), we filtered our set of accessions from the transect based on morphological characters observed in the greenhouse, as some diagnostic features can be more easily ascertained in flowering plants than in seeding plants without flowers, which is the typical stage of plants during seed collecting in the field. We used the position of outer involucral bracts in the mature inflorescence morphology as a diagnostic character (Kirschner & Štěpánek, 2011), marking those with dispersed or strongly reflexed bracts as T. officinale s.l. This selection was performed with the inflorescences obtained in the long vernalization experiment as nearly all plants reached flowering here. ...
The Urban Heat Island Effect (UHIE) is a globally consistent pressure on biological species living in cities. Adaptation to the UHIE may be necessary for urban wild flora to persist in cities, but experimental evidence is scarce. Here, we report evidence of adaptive evolution in a perennial plant species in response to the UHIE. We collected seeds from common dandelion (Taraxacum officinale) individuals along an urban–rural gradient in the city of Amsterdam (The Netherlands). In common-environment greenhouse experiments, we assessed the effect of elevated temperatures on plant growth and the effect of vernalization treatments on flowering phenology. We found that urban plants accumulate more biomass at higher temperatures and require shorter vernalization periods, corresponding to milder winters, to induce flowering compared to rural plants. Differentiation was also observed between different intra-urban subhabitats, with park plants displaying a higher vernalization requirement than street plants. Our results show genetic differentiation between urban and rural dandelions in temperature-dependent growth and phenology, consistent with adaptive divergence in response to the UHIE. Adaptation to the UHIE may be a potential explanation for the persistence of dandelions in urban environments.
... The analysis of the constructed tree according to the results of the RAPD analysis shows (Fig. 4a) that in general, it coincides with the phylogenetic relationships in the genus Taraxacum. However, T. officinale was in the same cluster with T. hybernum, although these two species belong to different sections (Kirschner and Š těpánek 2011). This suggests that the RAPD analysis is suitable for determining genetic intraspecific and interspecific polymorphism, however, this analysis is rather poor for elucidating the phylogenetic relationships between different species of dandelions. ...
Successful domestication and introduction into culture of new forms of rubber-bearing dandelions require not only determination of the content and quality of rubber in them, but also accurate species identification and genetic certification of valuable lines and forms. The objects of our study were three samples of Taraxacum kok-saghyz Rodin KAZ08-023, L2, Sary Jaz, brown-seeded and pink-seeded forms of Taraxacum hybernum Stev., as well as along one sample of Taraxacum brevicorniculatum Korol., Taraxacum glaucanthum (Ledeb.) DC., and Taraxacum officinale L. The aim of our work was to search of RAPD, ISSR, and SSR markers for the unambiguous identification of all studied dandelion forms. The RAPD primers OPD-07 and FS-10 are best suited for the detection of interspecific polymorphism, while the RAPD primers FS-10, OPC-05 and OPC-08 can be used for the detection of intraspecific dandelion polymorphism. The ISSR primers HB10, ISSR17, and ISSR36 were most effective for detecting interspecific polymorphism. For identification of the brown-seeded and pink-seeded forms of T. hybernum, primers HB10 and ISSR38 can be used. Primers HB10 and ISSR14 are best suited for identifying the three studied kok-saghyz samples. SSR primers TKS0091, TKS0097, TKS0107, and TKS0110 are suitable for SSR identification of pink-seeded and brown-seeded forms of T. hybernum. Only locus TKS0111 is suitable for unambiguous SSR identification of all three studied kok-saghyz samples.
... In the regions without sexual common dandelions, local populations consist of few to numerous distinct apomictic lineages, morphologically and genetically recognizable entities, sometimes referred to as microspecies, under binomials. Hundreds of microspecies within the T.officinale group have been described in Europe (Kirschner & Štěpánek, 2011). ...
DNA methylation is one of the mechanisms underlying epigenetic modifications. DNA methylations can be environmentally induced and such induced modifications can at times be transmitted to successive generations. However, it remains speculative how common such environmentally induced transgenerational DNA methylation changes are and if they persist for more than one offspring generation. We exposed multiple accessions of two different apomictic dandelion lineages of the Taraxacum officinale group (Taraxacum alatum and T. hemicyclum) to drought and salicylic acid (SA) treatment. Using methylation-sensitive amplified fragment length polymorphism markers (MS-AFLPs) we screened anonymous methylation changes at CCGG restriction sites throughout the genome after stress treatments and assessed the heritability of induced changes for two subsequent unexposed offspring generations. Irrespective of the initial stress treatment, a clear buildup of heritable DNA methylation variation was observed across three generations, indicating a considerable background rate of herit-able epimutations. Less evidence was detected for environmental effects. Drought stress showed some evidence for accession-specific methylation changes, but only in the exposed generation and not in their offspring. By contrast, SA treatment caused an increased rate of methylation change in offspring of treated plants. These changes were seemingly undirected resulting in increased transgenerational epigenetic variation between offspring individuals, but not in predictable epigenetic variants. While the functional consequences of these MS-AFLP-detected DNA methylation changes remain to be demonstrated, our study shows that (1) stress-induced transgenerational DNA methylation modification in dandelions is genotype and context-specific; and (2) inherited environmental DNA methylation effects are mostly undirected and not targeted to specific loci.
... Taraxacum ). This practice, however, is not correct, as used taxon names do not always represent the types, based on which sections were described and defined, and thus should not be used instead of a sectional name (e.g., Richards, 1985;Kirschner & Štěpánek, 1987Kirschner & Štěpánek, , 2011. Microspecies refers to morphologically homogenous narrow units with (to some extant) a defined distribution and clonal reproduction. ...
Gametophytic apomixis (asexual seed formation without syngamy of female and male gametes) is a highly interesting mechanism for researchers in plant biotechnology, genetics, evolutionary biology, and taxonomy. Apomixis evolved repeatedly and independently in the evolution of multiple genera. It is an effective reproduction barrier and, consequently, conserved apomictic genotypes may become overrepresented in nature. Apomictic plants may easily colonize free niches with only one or a few individuals and outcompete outcrossing plants. In spite of the indisputable pros of asexual reproduction, apomixis also has several cons. One of the most commonly mentioned is the accumulation of deleterious mutations in asexual lineages and decreased genetic variation. However, apomicts in general can be genetically highly diverse. The most common sources of this variation are the accumulation of mutations, hybridization with sexual plants, and facultative apomixis. Facultative apomicts are highly variable in their level of residual sexuality, which increases their genotypic and phenotypic variation. Even in the case of obligate apomicts, gene flow is possible due to functional male meiosis and the production of viable pollen grains by apomicts. Apomixis occurs in plant genera in which hybridization together with polyploidization play an important role in diversification and causes severe problems in taxonomy. How to accommodate apomictic taxa in taxonomic treatments, and understanding what should and what should not be referred to as a species are intriguing questions. This review aims to provide an overview of the main characteristics of “apomictic genera” and the approaches used to treat apomictic taxa within these genera. To achieve this aim, the review was divided into several parts. Firstly, the distinctive features of apomictic reproduction and apomictic taxa are described together with issues related to the taxonomic evaluation of apomictic taxa. The second part discusses approaches in the known apomictic genera, and the final part presents the authors’ view on important points, which need to be taken into account in the classification of apomictic taxa.
... The problem of understanding the chemical complexity of the genus Taraxacum is caused also by the complex taxonomy of the genus and the fact that the name T. officinale refers to various sexual and agamospermous species from the sect. Taraxacum [6]. These species may be both diploid and polyploid and the studied material is not sufficiently characterized from the point of view of taxonomy (cf. ...
Two isomers, (Z)- and (E)-palmityl 4-hydroxycinnamate [hexadecyl(2Z)-3-(4-hydroxyphenyl)prop-2-enoate and hexadecyl(2E)-3-(4-hydroxyphenyl)prop-2-enoate] were isolated for the first time from ligulate flowers of Taraxacum linearisquameum Soest (sect. Taraxacum). The highest amount of these compounds
was detected in pollen grains; 0.26 mg/100 mg DW of the (E)-isomer and 0.096 mg/100 mg DW of the (Z)-isomer. The structures of these compounds were elucidated by a combination of HPLC-ESI-Qtof-MS and 1D and 2D NMR spectroscopy. Their presence was confirmed in other species of Taraxacum, but they were not found in the male - sterile triploid agamospermous taxon T. parnassicum.
Keywords: Taraxacum, (Z)- and (E)-Palmityl 4-hydroxycinnamate, Ligulate flowers, NMR spectroscopy.
... For example, the name Taraxacum officianale F.H. Wigg shares the same type specimen as the name Leontodon taraxacum L. The two names therefore, refer to the same taxon. (Kirschner and Štěpánek 2011) The binomial name of scientific names result in a change in syntax when a taxon is moved to a different genus or if a name is not published according to formal nomenclatural rules. (Blackwelder 1967 ...
Scientific names serve to label biodiversity information: information related to species. Names, and their underlying taxonomic definitions, however, are unstable and ambiguous. This negatively impacts the utility of names as identifiers and as effective indexing tools in biological informatics where names are commonly utilized for searching, retrieving and integrating information about species. Semiotics provides a general model for describing the relationship between taxon names and taxon concepts. It distinguishes syntactics, which governs relationships among names, from semantics, which represents the relations between those labels and the taxa to which they refer. In the semiotic context, changes in semantics (i.e., taxonomic circumscription) do not consistently result in a corresponding and reflective change in syntax. Further, when syntactic changes do occur, they may be in response to semantic changes or in response to syntactic rules. This lack of consistency in the cardinal relationship between names and taxa places limits on how scientific names may be used in biological informatics in initially anchoring, and in the subsequent retrieval and integration, of relevant biodiversity information. Precision and recall are two measures of relevance. In biological taxonomy, recall is negatively impacted by changes or ambiguity in syntax while precision is negatively impacted when there are changes or ambiguity in semantics. Because changes in syntax are not correlated with changes in semantics, scientific names may be used, singly or conflated into synonymous sets, to improve recall in pattern recognition or search and retrieval. Names cannot be used, however, to improve precision. This is because changes in syntax do not uniquely identify changes in circumscription.
These observations place limits on the utility of scientific names within biological informatics applications that rely on names as identifiers for taxa. Taxonomic systems and services used to organize and integrate information about taxa must accommodate the inherent semantic ambiguity of scientific names. The capture and articulation of circumscription differences (i.e., multiple taxon concepts) within such systems must be accompanied with distinct concept identifiers that can be employed in association with, or in replacement of, traditional scientific names.
... Taraxacum; syn T. sect. Ruderalia (Kirschner and Štěpánek 2011)]. The apomictic sample was represented by various apomictic taxa from the T. sect. ...
The aim of the paper is to determine what happens
with plasmodesmata when mucilage is secreted into the periplasmic
space in plant cells. Ultrastructural analysis of the
periendothelial zone mucilage cells was performed on examples
of the ovule tissues of several sexual and apomictic
Taraxacum species. The cytoplasm of the periendothelial zone
cells was dense, filled by numerous organelles and profiles of
rough endoplasmic reticulum and active Golgi dictyosomes
with vesicles that contained fibrillar material. At the beginning
of the differentiation process of the periendothelial zone, the
cells were connected by primary plasmodesmata. However,
during the differentiation and the thickening of the cell walls
(mucilage deposition), the plasmodesmata become elongated
and associated with cytoplasmic bridges. The cytoplasmic
bridges may connect the protoplast to the plasmodesmata
through the mucilage layers in order to maintain cell-to-cell
communication during the differentiation of the
periendothelial zone cells.
... The common dandelion, Taraxacum officinale, is a widespread perennial plant species that is dispersed through seeds. For the description of the taxon T. officinale, formerly grouped in the sections Vulgaria and Ruderalia, see Kirschner & St ep anek (2011). In spring 2011, we collected seeds from apomictic dandelions in ten areas (which we refer to as populations) along a south-north transect from Luxembourg to central Sweden (Fig. 1). ...
Epigenetic modifications, such as DNA methylation variation, can generate heritable phenotypic variation independent of the underlying genetic code. However, epigenetic variation in natural plant populations is poorly documented and little understood. Here, we test if northward range expansion of obligate apomicts of the common dandelion (Taraxacum officinale) is associated with DNA methylation variation. We characterized and compared patterns of genetic and DNA-methylation variation in greenhouse-reared offspring of T. officinale that were collected along a latitudinal transect of northward range expansion in Europe. Genetic AFLP and epigenetic MS-AFLP markers revealed high levels of local diversity and modest but significant heritable differentiation between sampling locations and between the Southern, Central and Northern regions of the transect. Patterns of genetic and epigenetic variation were significantly correlated, reflecting the genetic control over epigenetic variation and/or the accumulation of lineage-specific spontaneous epimutations, which may be selectively neutral. In addition, we identified a small component of DNA methylation differentiation along the transect that is independent of genetic variation. This epigenetic differentiation might reflect environment-specific induction or, in case the DNA methylation variation affects relevant traits and fitness, selection of heritable DNA methylation variants. Such generated epigenetic variants might contribute to the adaptive capacity of individual asexual lineages under changing environments. Our results highlight the potential of heritable DNA methylation variation to contribute to population differentiation along ecological gradients. Further studies are needed using higher-resolution methods to understand the functional significance of such natural occurring epigenetic differentiation. This article is protected by copyright. All rights reserved.
... Las determinaciones taxonómicas fueron realizadas en el Departamento de Etnobotánica y Botánica Económica del Museo de Historia Natural de la UNMSM consultando bibliografía especializada (Tovar, 1957;Tovar, 1960;Gentry, 1993;Sagástegui & Leiva, 1993;Tovar, 1993;Beltrán, 1994;Albán, 1998;Beltrán et al., 1998;Renvoize, 1998;Tovar, 1998;Brack, 1999;Judd et al., 1999;Tovar & Oscanoa, 2002;Ayala, 2003;La Torre et al., 2003;La Torre et al., 2004;Pennington et al., 2004;Cano et al., 2005;Cano et al., 2006;Reynel et al., 2006;Scholz, 2006;Schmidt, 2008;Gutiérrez, 2009;Chemisquy et al., 2010;Castañeda, 2011;Kirschner & Stěpánek, 2011;Ostolaza, 2011;Refulio et al., 2012) (Peterson et al., 2001;Soreng et al., 2003;Zuloaga et al., 2003;Stančík & Peterson, 2007). Se empleó la forma estandarizada de citación de autores considerada en IPNI (2011). ...
Se presenta un trabajo detallado sobre las especies de plantas silvestres que los pobladores de Pisha utilizan como alimento para los animales domésticos, incluyendo datos sobre nombres vernáculos, origen de las plantas, tipos de animales que las consumen, partes consumidas, formas de suministro, hábito, distribución por formaciones vegetales y categorías de uso. El material botánico fue recolectado a través de caminatas etnobotánicas y el registro de los datos culturales se realizó a través del método de enlistado libre y entrevistas semiestructuradas a 102 informantes locales. Se registraron un total 117 especies con 114 nombres vernáculos, comprendidas en 98 géneros y 34 familias. Las familias reportadas con mayor frecuencia de uso fueron las Poaceae (19.5%) y Asteraceae (17.8%). El 70.1% de las plantas tienen hábito herbáceo, el 26.5% arbustivo, el 2.6% arbóreo y el 0.9% subarbustivo. 109 especies (66.9%) son consumidas por el ganado, 50 (30.7%) por animales menores y 4 (2.4%) por aves. 28 especies tienen uso exclusivo como alimento para animales, para las demás especies se registraron usos adicionales como medicinal, alimenticio, combustible, social, ambiental, tóxica y etnoveterinario.
... Taraxacum; syn T. sect. Ruderalia (Kirschner and Štěpánek 2011)]. The apomictic sample was represented by various apomictic taxa from the T. sect. ...
With the exception of the sunflower, little information concerning the micropyle ultrastructure of the family Asteraceae is available. The aim of our study was to compare the micropyle structure in amphimictic and apomictic dandelions. Ultrastructural studies using buds and flowers during anthesis have been done on the micropyle of the sexual and apomictic Taraxacum. In all of the species that were examined, the micropylar canal was completely filled with ovule transmitting tissue and the matrix that was produced by these cells. The ovule transmitting tissue was connected to the ovarian transmitting tissue. The micropyle was asymmetrical because the integument epidermis that forms the transmitting tissue was only on the funicular side. There was a cuticle between the obturator cells and epidermal cells on the other side of integument. The micropylar transmitting tissue cells and theirs matrix reached the synergid apex. The cytoplasm of the transmitting tissue cells was especially rich in rough endoplasmic reticulum (ER), dictyosomes, and mitochondria. No major differences were detected between the micropyle structure of the amphimictic and apomictic species; thus, a structural reduction of obturator does not exist. The ovule transmitting tissue is still active in apomictic dandelions despite the presence of the embryo and endosperm. Differences and similarities between the micropyle structure in the Asteraceae that have been studied to date are discussed.
... This approach avoids the ploidy confound and can test the hypothesis that a GPG strategy facilitates range expansion. In this study, we compare asexual lineages of Taraxacum officinale (common dandelions, Kirschner & St ep anek 2011) sampled along a geographic transect of historical range expansion. Taraxacum officinale has a well-described pattern of geographic parthenogenesis in Europe: sexual plants are self-incompatible diploids that occur in south-central Europe, whereas triploid asexuals co-occur with sexuals in south-central Europe but extend much further northwards into Scandinavia ( Mogie & Ford 1988;Menken, Smit & Nijs 1995;van Dijk 2003). ...
Phenotypic plasticity and broad ecological tolerance are hypothesized as important traits in the range expansion of asexual species, because individual asexual lineages have to face spatial and temporal environmental variation with limited opportunity for genetic adaptation. The hypothesis that asexual lineages are general‐purpose genotypes (GPG) has been previously tested, with mixed results, in species that have both sexual and asexual variants. Such comparisons can be confounded with intraspecific ploidy level differences that are often observed between the two reproductive types.
Avoiding the confounding effects of ploidy differences, we test whether northward range expansion selects for a GPG strategy in asexual lineages of the common dandelion ( Taraxacum officinale ), a species that shows geographic parthenogenesis. We compared the biomass of asexual lineages that were collected along a geographic transect from close to the asexuals’ area of origin (central Europe, where asexuals descend from sexual ancestors in mixed populations) towards their northern distribution edge (Northern Europe, where only asexual lineages occur) in three different experimental environments: optimal, drought and shaded conditions.
The geometric mean performance across test environments did not differ significantly between plants from different regions along the transect. However, southern lineages typically showed larger differences in biomass between different test environments, mainly caused by a relatively high performance in the optimal environment. Northern and mid‐latitude lineages showed more even performance across the different environments.
Synthesis . Our results suggest that phenotypic plasticity is important in the asexual range expansion of Taraxacum officinale and that range shifting in this species is accompanied by a change in phenotypic plasticity strategy from lineages with high ability to increase biomass in optimal growing conditions (master‐of‐some strategy) to lineages that maintain more constant performance in different environments (GPG or jack‐of‐all‐trades strategy) from core to range edge.
... En la región rioplatense se hallan 2 especies (Cabrera, 1963(Cabrera, , 1971(Cabrera, , 1974Ariza Espinar & Urtubey, 1998;iBoda, 2013 Obs. T. laevigatum y T. officinale pueden considerarse agregados de "microespecies" o razas apomícticas estrechamente relacionadas (Brouillet, 2006;Kirschner & Štěpánek, 2011). Aquí se mantiene la denominación adoptada en nuestro país (Ariza Espinar & Urtubey, 1998;iBoda, 2013 Hierbas de 5-30 cm alt. ...
... In fact, several wounds have been successfully re-surfaced by culturing autogenic keratinocytes cells678. The extensive uses of chives (Allium schoenoprasum), introduced sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale) range from culinary for flavouring dishes to medical purposes, such as antitussives, antiseptics, antifungals, antispasmodics, and anti-inflammatories, amongst other properties9101112. These pharmaceutical uses are associated with the rich amount of polyphenols which are found in these plants [13,14]. ...
The phenolic extract of chives flowers (Allium schoenoprasum, Liliaceae), introduced Sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale, Asteraceae) were characterised by High Performance Liquid Chromatography and incorporated in different concentrations onto atelocollagen thin films. In order to assess the biological impact of these phenolic compounds on cell viability, human immortalised non-tumorigenic keratinocyte cell line was seeded on the thin films and cell proliferation was determined by using an MTT assay. In addition, their antimicrobial activity was estimated by using an agar diffusion test. Data indicated the concomitance between cell viability and concentration of polyphenols. These findings suggest that these phenolic-endowed atelocollagen films might be suitable for tissue engineering applications, on account of the combined activity of polyphenols and collagen.
... Ruderalia Kirschner, H. Oellg. et Štěpánek, see also Kirschner and Štěpánek 2011). The North American members of this section are introduced and agamospermous. ...
Cultivation of the Russian dandelion (Taraxacum koksaghyz) as a rubber producing crop was abandoned more than 50 years ago. Recently the interest in the Russian dandelion has renewed, due to the increasing demand for natural rubber, health problems associated with Hevea rubber and the potential vulnerability of the Hevea production system. Morphological examination and genetic analyses demonstrated that all available ex situ germplasm collections of T. koksaghyz belonged to a single triploid apomictic clone that was misidentified as T. koksaghyz. Morphological, taxonomic and AFLP analyses show that this clone belongs to T. brevicorniculatum a species commonly co-occurring with wild populations of T. koksaghyz in the southeastern Kazakhstan. The type specimen of T. brevicorniculatum is no longer extant and we provide a detailed description and typification, and the characteristics that distinguish it from T. koksaghyz. The investigation of literature reports and herbarium collections indicates that T. koksaghyz seed batches in the past were often contaminated with T. brevicorniculatum. We discuss the possible reasons for the worldwide replacement of T. koksaghyz by a single T. brevicorniculatum clone. New introductions in ex situ collections are urgently needed.
... Ruderalia Kirschner, H. Oellg. et Štěpánek, see also Kirschner and Štěpánek 2011). The North American members of this section are introduced and agamospermous. ...
... T. sect. Ruderalia) [51,52]. The first group comprises a complex of six morphologically closely related accessions (T. ...
Dandelions (genus Taraxacum) comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds) in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe) were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP) markers. Our results indicated that significant genetic similarity existed within accessions with low numbers of genotypes. Genotypic variability was high among accessions but low within accessions. Clustering methods discriminated individuals into nine groups corresponding to their phenotypes. Furthermore, two groups of apomictic genotypes were observed, which suggests that they had different asexual histories. A matrix compatibility test suggests that most of the variability within accession groups was mutational in origin. However, the presence of recombination was also detected. The accumulation of mutations in asexual clones leads to the establishment of a network of clone mates. However, this study suggests that the clones primarily originated from the hybridisation between sexual and apomicts.
... The problem of understanding the chemical complexity of the genus Taraxacum is caused also by the complex taxonomy of the genus and the fact that the name T. officinale refers to various sexual and agamospermous species from the sect. Taraxacum [6]. These species may be both diploid and polyploid and the studied material is not sufficiently characterized from the point of view of taxonomy (cf. ...
(Z)- and (E)-2-β-D-glucopyranosyloxy-4-methoxycinnamic acids (GM-CA) belong to the main compounds of water-alcoholic extracts of Chamomilla recutita. The quantities of GMCA and apigenin in anthodia (flower heads) of diploid and tetraploid C. recutita cultivars were studied. The ploidy of a plant does not significantly influence the percentage of GMCA, in contrast to the total GMCA content in anthodia of diploid and tetraploid cultivars. Progenies of selected tetraploid plants with significantly high (9.95 mg/g) and low (5.47 mg/g) contents of GMCA were also evaluated. The higher and lower values of GMCA were conserved in the progeny generation, with significant differences in GMCA content found between the two groups of progenies.
Les groupes apomictiques, définis par leurs espèces non sexuées ou agamo-espèces, sont souvent consi-dérés comme les plus difficiles de la flore. En France, ce problème concerne principalement des genres appartenant aux Asteraceae (Hiera-cium L., Pilosella Vaill., Taraxacum F.H. Wigg.), aux Ranunculaceae (sur-tout dans le groupe de Ranunculus auricomus L.) et aux Rosaceae (Alche-milla L., Cotoneaster Medik., Poten-tilla L., Rubus L., Sorbus L.). Cette dernière famille possède aussi le genre Rosa L. sect. Caninae DC. et ses kleptons 1 (MErCiEr in Tison et al., 2014), un cauchemar taxonomique en comparaison duquel les apomic-tiques proprement dits ont la com-plexité d'un exercice de calcul de CE2. D'autres familles comprennent de tels groupes, mais, à l'échelle de la France tout au moins, ces derniers restent relativement abordables en raison de leur faible nombre de taxons (Dryopteridaceae : Dryopteris Adans. ; Liliaceae : Gagea salisb. ; Or-chidaceae : Gymnadenia r. Br. ; etc.). La présente note concerne les genres Hieracium (excluant Pilosella) et Taraxacum qui illustrent bien les questions taxonomiques liées à l'apomixie proprement dite. Malgré leur mauvaise réputation, ces deux genres ont l'avantage de représen-ter la forme la plus simple du phé-nomène, avec des agamo-espèces, certes nombreuses, mais n'échan-geant théoriquement pas de gènes, de sorte que les seuls problèmes qu'elles posent sont leur recense-ment et leur caractérisation. Les choses sont moins schématiques chez Pilosella ou Rubus qui mêlent apomixie et multiplication sexuée et montrent parfois toutes les formes de passages entre hybrides occa-sionnels et agamo-espèces.
Dandelion (Taraxacum) in European and Asian phytotherapy The genus Taraxacum (family Asteraceae) belongs to the largest and most complicated apomictic complexes. So far, over 2,800 species classified in 60 sections have been described. The natural range of the genus is almost cosmopolitan, with monk seals found on every continent except Antarctica, but their distribution is very uneven. The largest centers of Taraxacum diversity are in Central Asia and Southern Europe. Species belonging to the genus Taraxacum have long been used as food. Young leaves are eaten raw in salads, and dried as an addition to teas or used as spices. Dried roots are used to prepare teas and a coffee substitute, while the flowers and infl orescences are used to produce syrups, wines and are added to beers and soft drinks. Above all, however, dandelions are valued herbal plants since ancient times, used in traditional European, Chinese and Indian medicine to treat liver diseases, kidney stones, stomach diseases, abdominal pain, diarrhea, cough, bladder diseases, gout, edema, and even cancerous. In the modern, very rich scientific literature, the medicinal properties of dandelions have been partially confirmed, but the results are often ambiguous and in some cases contradictory.
The Urban Heat Island Effect (UHIE) is a globally consistent pressure on species living in cities. Rapid adaptation to the UHIE may be necessary for urban wild flora to persist in cities, but experimental evidence is lacking. Here, we report the first evidence of genetic differentiation in a plant species in response to the UHIE. We collected seeds from common dandelion ( Taraxacum officinale ) individuals along an urban-rural gradient in the city of Amsterdam (The Netherlands). In common-environment greenhouse experiments, we assessed the effect of elevated temperatures on plant growth and the effect of vernalisation treatments on flowering phenology. We found that urban plants accumulate more biomass at higher temperatures and require shorter vernalisation to induce flowering compared to rural plants. Differentiation was also observed between different intra-urban subhabitats, with park plants displaying a higher vernalisation requirement than street plants. Our results show strong differentiation between urban and rural dandelions in temperature-dependent growth and phenology, consistent with adaptive divergence in response to the UHIE. Rapid adaptation to the UHIE may be a potential explanation for the widespread success of dandelions in urban environments.
Summary statement
The urban heat island effect (UHIE) is the most prominent and globally consistent characteristic of environmental change due to urbanisation, severely impacting human populations in cities as well as the cohabiting wildlife. Despite the profoundly mitigating effect of vegetation on urban heat, evidence for plant adaptation to the UHIE has been lacking. Here we provide the first experimental evidence to date, demonstrating adaptation in urban dandelions in response to elevated temperatures, similar to the UHIE. We furthermore show an urban-rural differentiation in flowering response to shorter vernalisation times (cold winter period to activate the onset of flowering in early spring). Given the predominantly asexual apomictic mode of reproduction in dandelions, this evolution is likely the result of environmental filtering on a diverse population of clonal genotypes. We conclude that plant adaptation to the UHIE exists and recommend future studies to contrast our findings with those in outcrossing sexual plant systems. Studies of urban heat adaptation can bring impactful contributions to building climate change-resilient environments and plants should be an integral part of this research.
Wild greens can contribute to the human diet as an important source of essential nutrients and drugs. Since environmental factors, including soil properties, may affect the chemical composition of plants, it is necessary among others to assess various habitats in terms of their usefulness for wild plant harvesting and to study impact of environmental factors on the qualitative and quantitative chemical composition of plants. This study was aimed at (1) examining the mineral composition of leaves of three dandelion microspecies, (2) determining the variability of macro- and microelement concentrations in dandelion leaves from populations growing on salty, brackish and non-saline coastal meadows, and (3) assessing the effects of different habitat conditions on the mineral composition of dandelion leaves. It was hypothesized that dandelion microspecies would differ significantly in the mineral composition of leaves. It was also expected that soil conditions would significantly affect nutrient concentrations in dandelion leaves, with soil salinity being the most important factor that differentiated studied populations. Leaves of three dandelion microspecies (Taraxacum balticum, T. nordstedtii, T. haematicum) were harvested in Baltic costal grasslands, along the soil salinity gradient, to determine macro-and microelement concentrations. Soil samples collected in the closest vicinity of the harvested plants showed the study sites to differ significantly in their soil properties. Moderately saline and organic soils, rich in potassium (K), magnesium (Mg), and calcium (Ca), supported T. balticum. Moderately or weakly saline and non-saline, organic or mineral soils, with lower median values of K, Mg, and Ca, were typical of T. nordstedtii sites, while the lowest median values of all the soil properties studied were found for T. haematicum sites. Our results proved that dandelion microspecies differ significantly in the mineral composition of their leaves. The between-microspecies differences were significant for all the macroelements except magnesium and all the microelements except molybdenum. Most of the macro- and microelements in leaves of the dandelion microspecies correlated positively and significantly with the soil properties, the strongest correlations being found for soil salinity and the leaf Na, Mn, Ca, Fe, K and Zn contents, followed by soil pH and the leaf Na, Mn, Fe, K, Ca, Zn and Mg. Moreover, the impact of soil properties on the mineral contents in leaves of the dandelions we examined seems to be stronger than the genetic differences between dandelion microspecies. Results of our studies on mineral composition of dandelion leaves lend support to the contention that wild greens provide essential mineral nutrients to the diet. Coastal meadows, fed by the brackish water of the Baltic Sea and free of anthropogenic pollution, are a good habitat to collect wild greens from.
The renaissance of cultivation of
Taraxacum koksaghyz (Asteraceae) as a
rubber producer in Germany. Cultivation of
diploid, sexual Taraxacum koksaghyz from Central
Asia as rubber producer is re-established in
Germany. The invasive capability of this species
with regard to the native vegetation is extremely
low, as shown in competition experiments in
grassland and agricultural fields which led to a
complete collapse of T. koksaghyz populations
within one year. Hybridization events with native
Taraxacum-populations were not observed. The
early stage of domestication of T. koksaghyz is
characterized by an extraordinary morphological
variability which is documented.
Recent international developments make access to biological resources across international borders more difficult than in the past. Local access to biological resources, including plant natural products, thus becomes more important. In order to evaluate the opportunities to access bioactive natural products in our region, we here start a series of dedicated articles assessing the chemical diversity of plant taxa, native and naturalized, in the region of Schleswig-Holstein, Germany. The region has only a limited biodiversity with about 1500 species of higher plants growing in the wild. Our aims are the following: (1) A complete review of the natural products reported from taxa occurring in Schleswig-Holstein from any part of their distribution range. (2) Proof or disproof, whether these substances are also occurring in populations of the taxa at hand occurring in the wild in Schleswig-Holstein. (3) To establish analytical GLC-MS and/or HPLC-DAD-MS systems to identify and quantify these compounds. (4) Initiation of dedicated efforts to unravel the array of secondary metabolites contained in species from the Schleswig-Holstein region not yet investigated. (5) Search for chemically defined intraspecific taxa, i.e. chemically differing lineages of morphologically indistinguishable plant taxa, by comparing plants from Schleswig-Holstein with plants collected in other regions. The survey into the plant natural products’ chemodiversity of the flora of Schleswig-Holstein begins with a review of the natural products from Schleswig-Holstein members of the Cichorieae tribe of the Asteraceae family. The Cichorieae tribe of the Asteraceae family, which encompasses 94 genera and about 1500 species and innumerous microtaxa worldwide (Kilian et al. in Systematics, evolution and biogeography of the Compositae, IAPT, Vienna, 2009), is represented by only 17 genera in Schleswig-Holstein: Arnoseris, Chondrilla, Cicerbita, Cichorium, Crepis, Hieracium, Hypochaeris, Lactuca, Lapsana, Leontodon, Picris, Pilosella, Scorzonera, Scorzoneroides, Sonchus, Taraxacum, and Tragopogon. In total, 48 species (50 taxa including the two species with two distinct subspecies each in the region and treating the sections in the hyper-species-rich genus Taraxacum as species here), occur in Schleswig-Holstein. For all of the genera and all but six of the species (Hieracium fuscocinereum, Lactuca macrophylla, Sonchus palustris, and Taraxacum sections Celtica, Hamata, and Obliqua), the array of plant natural products has already been investigated to some degree. However, for only two taxa (Pilosella officinarum and Tragopogon pratensis subsp. minor) also plants from the region of Schleswig-Holstein have been studied and for only very few taxa, such as Cichorium intybus and Taraxacum officinale, all major classes of natural products have been investigated in detail so far.
In almost all North American literature, including in British Columbia, weedy Taraxacum species have been named as Taraxacum officinale F.H.Wigg and Taraxacum erythrospermum Andrz. ex Besser (or Taraxacum laevigatum DC.). This coarse taxonomic approach ignores great diversity in morphology, ecology, and geographical distributions among the exotic established species. Taxonomic refinement would facilitate floristics and ecological studies when exotic Taraxacum species are involved, and the taxonomy of native Taraxacum must first determine which are and which are not native species, which in turn requires knowledge of sectional identity of any specimen. Exotic Taraxacum specimens were identified to species and taxonomic sections using refined species and sectional concepts that align with taxonomic standards used in the native ranges of the species in Europe. Seven exotic sections and one informally named group are found to be present in British Columbia (Borea, Boreigena, Celtica, Erythrosperma, Hamata, Naevosa, Taraxacum, and the Taraxacum fulvicarpum group). The number of exotic Taraxacum species known to occur in British Columbia to date exceeds 100. A key to the exotic sections of British Columbia Taraxacum is presented and the sections are characterized. Species known to date are listed by their sectional placement. Notes are also presented on distinguishing native from exotic Taraxacum in British Columbia.
The species-rich and widespread genus Taraxacum F. H. Wiggers, 1780 (Asteraceae subfamily Cichorioideae) is one of the most taxonomically complex plant genera in the world, mainly due to its combination of different sexual and asexual reproduction strategies. Polyploidy is usually confined to apomictic microspecies, varying from 3x to 6x (rarely 10x). In this study, we focused on Taraxacum sect. Taraxacum (= T. sect. Ruderalia; T. officinale group), i.e., the largest group within the genus. We counted chromosome numbers and measured the DNA content for species sampled in Central Europe, mainly in Czechia. The chromosome number of the 28 species (T. aberrans Hagendijk, Soest & Zevenbergen, 1974, T. atroviride Štěpánek & Trávníček, 2008, T. atrox Kirschner & Štěpánek, 1997, T. baeckiiforme Sahlin, 1971, T. chrysophaenum Railonsala, 1957, T. coartatum G.E. Haglund, 1942, T. corynodes G.E. Haglund, 1943, T. crassum H. Øllgaard & Trávníček, 2003, T. deltoidifrons H. Øllgaard, 2003, T. diastematicum Marklund, 1940, T. gesticulans H. Øllgaard, 1978, T. glossodon Sonck & H. Øllgaard, 1999, T. guttigestans H. Øllgaard in Kirschner & Štěpánek, 1992, T. huelphersianum G.E. Haglund, 1935, T. ingens Palmgren, 1910, T. jugiferum H. Øllgaard, 2003, T. laticordatum Marklund, 1938, T. lojoense H. Lindberg, 1944 (= T. debrayi Hagendijk, Soest & Zevenbergen, 1972, T. lippertianum Sahlin, 1979), T. lucidifrons Trávníček, ineditus, T. obtusifrons Marklund, 1938, T. ochrochlorum G.E. Haglund, 1942, T. ohlsenii G.E. Haglund, 1936, T. perdubium Trávníček, ineditus, T. praestabile Railonsala, 1962, T. sepulcrilobum Trávníček, ineditus, T. sertatum Kirschner, H. Øllgaard & Štěpánek, 1997, T. subhuelphersianum M.P. Christiansen, 1971, T. valens Marklund, 1938) is 2n = 3x = 24. The DNA content ranged from 2C = 2.60 pg (T. atrox) to 2C = 2.86 pg (T. perdubium), with an average value of 2C = 2.72 pg. Chromosome numbers are reported for the first time for 26 species (all but T. diastematicum and T. obtusifrons), and genome size estimates for 26 species are now published for the first time.
The genus Taraxacum is used in the assessment of soil contamination with heavy metals. There are relatively few studies using sections or species representing this genus. The presented research was conducted in Poland on two habitats, varied in terms of nutrients and metals content. The content of selected metals in leaves and roots of Taraxacum sect. Taraxacum was determined. It was found that in the conditions of increased content of metals in the soil, the analysed species representing sect. Taraxacum accumulate higher amounts of metals in their leaves and roots. Factors of translocation of selected metals from roots to leaves of Taraxacum species, representing the Taraxacum section, are affected by i.a. soil reaction and the content of Corg, Ntot. in the soil. No influence of soil properties on metal biological concentration factor was observed.
Taraxacum species collected in the Azores, Madeira and the Canary Islands are reported, described and illustrated. Most of them are new records, especially for the Canary Islands flora where T. canariense is the only one reported previously. Taraxacum guanchicum A. Galán & E. Linares & Vicente Orell. is described as a new species from Gran Canaria and Tenerife. A key to and a distribution map of all the species studied are provided.
Dandelion (Taraxacum officinale agg.) is a common forb species in grasslands in Europe. Although sometimes regarded as a valuable forage herb, it may become a weed, especially in arable land. There is limited information on the response of Taraxacum to long-term grassland management practices. Therefore, we analysed cover and dry-matter standing biomass of Taraxacum in a long-term (1998-2012) grazing experiment on an Agrostis capillaris grassland. The following treatments were laid out on formerly abandoned grassland: (i) intensive grazing (IG); (ii) extensive grazing (EG); (iii) first cut followed by intensive grazing (ICG); (iv) first cut followed by extensive grazing (ECG); and (v) unmanaged grassland (U). During the first 10 years, all defoliation treatments (i-iv) supported the presence of Taraxacum, and the lowest proportion was recorded in the unmanaged treatment (U). During the final 7 years of the study, combined cutting and grazing promoted Taraxacum cover more than that of grazing only (ICG > IG > ECG > EG). Cover of Taraxacum was negatively affected by increasing sward height where Taraxacum plants had lower fitness. Due to the relatively strong relationship between percentage cover of Taraxacum and its dry-matter biomass, percentage cover could be used as a simple method for the assessment of biomass of Taraxacum in a sward. Results are discussed in the context of adapting the management of A. capillaris grassland as a simple method for control of Taraxacum abundance, particularly in situations of extensification or abandonment.
Six new species of Taraxacum sect. Taraxacum from Finland are described here based on both feld studies and cultivated material. Their morphology is compared with closely related species, and a survey of their known distribution is given. Holotypes are deposited to H. T. cabannaeforme have been found at many locations in southern Finland, but the number of plants is usually small. T. coartatiforme is locally common in Joensuu, North Karelia; elsewhere it is very rare. T. os-siclivosum is distributed from eastern Finland to South Savo, being more common in the latter. Although T. sinus-avis is evident especially in North Karelia, occurrences in southern Finland and Sweden indicate that the distribution area may be quite extensive. T. subinvestiens ja T. volitans are known only to exist in Joensuu, North Karelia. Additional studies are required to clarify their total distributions.
Little is known about changes in the abundance and species composition of dandelions (Taraxacum) in Finland. However, Eastern Finland, the biogeographical provinces of Karelia ladogensis and Karelia borealis, has been explored again since 1985. Carl-Erik Sonck collected dandelions there mainly in the 1940s and published his results later (Sonch 1964a). The comparison revealed that changes were considerable over this 60-year period. Species of the section Taraxacum had become more frequent, while those of the sections Borea and Erythrosperma had declined. After Sonck, 88 species were found to be new to North Karelia and 24 to Ladoga Karelia. Respectively, 16 and 33 species were not re-discovered in these provinces. The figures are approximate, particularly concerning Karelia ladogensis, because a larger part of this province has not been studied since 1945 when most of its territory was ceded to the former Soviet Union.
Dandelion (Taraxacum spec) is a wild plant that has been used for centuries as a traditional medicine in the relief and treatment of several diseases. This use is due to the presence of sesquiterpenes, saponins, phenolic compounds, flavonoids, and sugars, among others, found in the organs of the plant.
The aim of this work is to provide a current review of developments and trends in research on the Taraxacum genus, with a focus on traditional uses and pharmacological properties. This should shed light on the potential of this plant as an attractive commercial herbal medicine.
Documents were collected, analyzed, and classified for information regarding medical, agronomic, genetic, and biological aspects of the Taraxacum species. This process was based on a thorough search of documents indexed by scientific search engines.
Two important periods of research on Taraxacum have been identified: the first, between 1930-1950; and the second, from 1990 to today. During the former, agricultural and genetics research on this plant were, due to the shortage of natural rubber, the focus. In contrast, the main drive in Taraxacum research is now the recovery of bioactives and/or applications in medicine. Pharmacology is the main area in which these plants have been tested, thanks in part to its widely known traditional uses; however, there is less than enthusiastic interest in further human clinical trials. In other areas, Taraxacum sports an enormous list of compounds of industrial interest; and while it is true that only a small amount of these compounds are immediately available in Taraxacum organs and makes it relatively commercially unattractive, only scarce efforts have been made to improve yields. Compounding this issue, most studies of its growth and cultivation have been focused mainly on controlling it as a weed detrimental to certain industrial crops. To wit, in spite of all the research carried out, less than 1% of all the species identified so far (>2,500) have been studied (including T. officinale, T. coreanum, T. mongolicum and T. platycarpum). This is a indication of the little knowledge that we have about this genus so far. Biotechnology (involving genetics, agriculture, and biology) is the most powerful means by which to take advantage of all the medicinal potential of Taraxacum. Great strides have been made in identifying metabolic pathways for synthesizing terpenes, one of the most important compound families in clinical applications. In order to improve yield and performance of the plant in the field, greenhouse cultivation is another aspect taken into account, deriving an increase in recovery of bioactives from Taraxacum organs. Even while considering that only a few species have been studied, their different biochemical and cultivation profiles indicate huge potential for qualitative improvements in composition through genetic engineering, thus directly impacting pharmacological properties.
Taraxacum is has been traditionally considered a natural remedy, well-inserted into popular knowledge, but with low commercial applicability. Only once the recovery of pure and highly reactive compounds can be pursued at (a qualitatively and quantitatively attractive) economical scale, human clinical trials would be of interest in order to prove their efficacy and safety, positioning Taraxacum as an important commercial source of natural drugs.
Copyright © 2015. Published by Elsevier Ireland Ltd.
Apomixis in dandelions (Taraxacum: Asteraceae) is encoded by two unlinked dominant loci and a third yet undefined genetic factor: diplosporous omission of meiosis (DIPLOSPOROUS, DIP), parthenogenetic embryo development (PARTHENOGENESIS, PAR), and autonomous endosperm formation, respectively. In this study, we determined the chromosomal position of the DIP locus in Taraxacum by using fluorescent in situ hybridization (FISH) with bacterial artificial chromosomes (BACs) that genetically map within 1.2-0.2 cM of DIP. The BACs showed dispersed fluorescent signals, except for S4-BAC 83 that displayed strong unique signals as well. Under stringent blocking of repeats by C0t-DNA fragments, only a few fluorescent foci restricted to defined chromosome regions remained, including one on the nucleolus organizer region (NOR) chromosomes that contains the 45S rDNAs. FISH with S4-BAC 83 alone and optimal blocking showed discrete foci in the middle of the long arm of one of the NOR chromosomes only in triploid and tetraploid diplosporous dandelions, while signals in sexual diploids were lacking. This agrees with the genetic model of a single dose, dominant DIP allele, absent in sexuals. The length of the DIP region is estimated to cover a region of 1-10 Mb. FISH in various accessions of Taraxacum and the apomictic sister species Chondrilla juncea, confirmed the chromosomal position of DIP within Taraxacum but not outside the genus. Our results endorse that, compared to other model apomictic species, expressing either diplospory or apospory, the genome of Taraxacum shows a more similar and less diverged chromosome structure at the DIP locus. The different levels of allele sequence divergence at apomeiosis loci may reflect different terms of asexual reproduction. The association of apomeiosis loci with repetitiveness, dispersed repeats, and retrotransposons commonly observed in apomictic species may imply a functional role of these shared features in apomictic reproduction, as is discussed.
Taraxacum sect. Erythrosperma (H. Lindb.) Dahlst. in Corsica was revised on the basis of a detailed study of old collections used by J. L. van Soest in his first studies of the genus in Corsica, and new collections and cultivations. All the names based on the specimens from Corsica are interpreted, 16 species of the section are recognized. Particular attention was paid to a group of the sect. Erythrosperma with a number of endemics or subendemics, around T. purpureomarginatum. Four new species are described. A number of names are newly interpreted and typified. All the specimens studied are cited, with the exception of taxa common in Europe. All the species of the sect. Erythrosperma known from Corsica are agamospermous; ten species proved to be triploid or tetraploid. All the taxa endemic to, or having a substantial part of their distribution range in Corsica are given full description. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
A checklist of vascular plants of the Czech Republic is provided, based on the Kubát et al’s Key to the flora of the Czech Republic from 2002 and volumes 7 and 8 of the Flora of the Czech Republic as taxonomic reference, and incorporating numerous floristic, taxonomic and nomenclatural novelties. Native, alien, both naturalized and casual, as well as frequently cultivated taxa are included. Species, subspecies, nothospecies and nothosubspecies, and some frequently used variety names are listed. For cultivated plants, the taxonomic rank of Group is widely applied. For practical purposes, 188 species aggregates and other informal species groups are defined. References are made to corresponding taxonyms in the Key or the two Flora volumes when name or orthography changes occurred. Most important changes in nomenclature, taxonomy, recently described taxa and additions to the country’s flora are annotated. The flora of the Czech Republic includes 3557 species (plus 194 additional subspecies) and 609 (plus 13 additional nothospecies) hybrids. Of these, 2256 species are native, 464 naturalized (228 archaeophytes and 236 neophytes) and 837 casual aliens. Further, 324 cultivated taxa of different ranks are listed. The list includes categorizations of alien species of Pyšek et al.’s second edition of the Catalogue of alien plants of the Czech Republic and Red List categorizations of Grulich’s third edition of the Red List of vascular plants of the Czech Republic, both published in Preslia in 2012.
The genus Gracilaria (Gracilariales, Rhodophyta) has long been one of the most taxonomically challenging groups of red algae as a result of the high number of species, small number of distinctive characters, and the high levels of morphological plasticity among vegetative and reproductive features. Recently, DNA sequence phytogenies based on the chloroplast-encoded rbcL gene have resolved many systematic questions in this genus. This study provides an rbcL-based phylogeny of the most derived lineage of Gracilaria sensu stricto, the assemblage containing the generitype, G. bursa-pastoris. In this clade, two poorly known and overlooked species of Gracilaria, G. flabelliformis and G. apiculata, were found to be very common members of the genus in the tropical western Atlantic. Gracilaria apiculata belongs to the G. cervicornis complex, a clade composed of highly branched species with terete to compressed main axes, while G. flabelliformis is a member of a clade composed only of Atlantic flat species. Exceedingly distinct phenotypes for each of these species were observed in our circumscription and are described as new subspecies, along with detailed morphological characterization for each of these taxa: G. flabelliformis subsp. aionana subsp. nov. G. flabelliformis subsp. simplex subsp. nov., and G. apiculata subsp. candelabriformis subsp. nov., and G. isabellana nom. nov., a replacement name for G. lacinulata (Vahl) Howe which is a homonym of G. lacinulata (Küzing) Piccone.
of flattened species of Gracilaria (Gracilariceae, Rhodophyta) from Korea based on morphology and protein-coding plastid rbcL and psbA sequences. Phycologia 45: 520– 528. Despite extensive studies on cylindrical Gracilaria species, the taxonomy and phylogeny of the flattened species of the genus has received little attention. We studied the morphology and molecular phylogeny of three flattened species of Gracilaria, hitherto reported from Korea. Gracilaria textorii is characterized by having a wider blade relative to other species, margins entire or proliferous, coriaceous thallus texture, one to three large cells in the medulla, and shallow male conceptacles. Gracilaria cuneifolia is membranous in texture, and has shallow spermatangial conceptacles (approximately 10 m in depth). We generated psbA and rbcL sequences from 32 specimens of G. textorii, G. cuneifolia and its putative relatives in Korea and surrounding waters. Twenty-three specimens of G. textorii from Korea, including two from Japan, were almost identical in both rbcL and psbA regions, except for some specimens that were different by one to four nucleotides. Three specimens of G. cuneifolia were identical in both rbcL and psbA. However, we found no evidence for the occurrence of G. incurvata in Korea. In all analyses of rbcL, psbA, and rbcL psbA data sets, G. textorii was determined to be a unique species, with G. incurvata from Japan as a sister species. Gracilaria cuneifolia is more closely related to the G. tikvahiae group from the Atlantic than G. textorii and G. incurvata.
Mediterranean reports of Gracilariaceae species, in particular those assigned to the G. verrucosa complex, were re-examined with the use of molecular tools, in order to verify their systematic position and better understand their distribution. Within this complex, we recognized four distinct taxa: Gracilariopsis longissima, Gracilaria gracilis, Gracilaria longa and a possible new species. The rbcL gene sequences, together with those of other terete Mediterranean entities, were included in a broad molecular phylogeny of the family. The reproductive characters of the studied taxa do not fit completely with published hypothesis on the generic and intrageneric relationships, suggesting that the anatomy of some subgroups should be better characterized.
The program MODELTEST uses log likelihood scores to establish the model of DNA evolution that best fits the data.
AVAILABILITY: The MODELTEST package, including the source code and some documentation is available at http://bioag.byu. edu/zoology/crandall_lab/modeltest.html.
MrBayes 3 performs Bayesian phylogenetic analysis combining information from different data partitions or subsets evolving under different stochastic evolutionary models. This allows the user to analyze heterogeneous data sets consisting of different data types—e.g. morphological, nucleotide, and protein—and to explore a wide variety of structured models mixing partition-unique and shared parameters. The program employs MPI to parallelize Metropolis coupling on Macintosh or UNIX clusters.
Availability: http://morphbank.ebc.uu.se/mrbayes
Contact: fredrik.ronquist@ebc.uu.se
*
To whom correspondence should be addressed.
Introduction to general state-space Markov chain theory. In W. R. Gilks, S. Richardson, and D. J. Spiegelhalter (Eds.), Markov Chain Monte Carlo in Practice, Chapter 4, pp. 59-74. London: Chapman and Hall. Yang, Z., R. Nielsen, N. Goldman, and A.-M. K. Pedersen (2000). Codon- substitution models for heterogeneous selection pressure at amino acid sites. Genetics 155, 431-449. Yang, Z. and B. Rannala (1997). Bayesian phylogenetic inference using DNA sequences: A Markov chain Monte Carlo method. Molecular Biology and Evolution 1, 717-724. Yang, Z. H. (1993). Maximum-likelihood-estimation of phylogeny from DNA- sequences when substitution rates differ over sites. Molecular Biology and Evolution I0(6), 1396-1401. Zuckerkandl, E. (1987). On the molecular evolutionary clock. Journal of Molec- ular Evolution 26, 34-46. Zuckerkandl, E. and L. Pauling (1962). Molecular disease, evolution, and genic heterogeneity. In M. Kasha and B. Pullman (Eds.), Horizons in Biochem- istry, pp. 189-225. Ne
The nomenclature and typification of the sections in the genus Taraxacum Wigg. are discussed. The genus is typified by a specimen of Leontodon taraxacum from Linnaeus' Flora Lapponica for which the modern synonym is T. campylodes Hagl. This becomes the type of T. officinale Weber, and T. sect. Crocea M. P. Christiansen to which T. campylodes was assigned becomes a synonym of T. sect. Taraxacum. It is considered that the sections and subsections published by Handel-Mazzetti (1907) are validated in the table of contents in that work. The problems resulting from the earlier use of species in two different rank concepts in this largely agamospermous genus are highlighted, as are early incorrect citations, and recent transgressions of the ICBN. The sections of the genus are listed in full, with type species and synonymy. Two new sections are described, T. sect. Borea Sahlin and T. sect. Celtica Richards and Sahlin.
The sectional nomenclature in Taraxacum (Cichoriaceae) is discussed (cf. Richards, Taxon 34:633-644, 1985). The status of Dahlstedt's sectional names and their typification are dealt with. Results of this analysis are compared with infrageneric taxa published by Handel-Mazzetti (1907) and with the Richards paper. Attention is paid to the typification of the sections Palustria, Borealia, Ceratophora, Erythrosperma and Subvulgaria. The name T. sect. Vulgaria (Dahlst.) Dahlst. is shown to be illegitimate; a new section is described to accommodate the most common group of dandelions in central and northwestern Europe. A list of corrections and additions to the Richards sectional list is added.
Kirschner, J. & Štňpánek, J.: A nomenclatural checklist of supraspecific names in Taraxacum. –Taxon 46: 87‐98. 1997. – ISSN 0040‐02
Names of subdivisions of the genus Taraxacum are listed and critically analysed. Validity and legitimacy are determined, all valid names are given types, and type specimens are selected and quoted where available. Comments are confined to the nomenclatural status of the names; for important taxonomic synonyms the accepted names are given, and names considered correct are highlighted.
Maps of distribution of some genera of Rosaceae (Cydonia, Chaenomeles, Pyrus, Malus, Eriobotrya, Sorbaronia, Amelanchier, Cotoneaster, Crataegus, Prunus) in Europe in order to complement Flora Europaea. Information is devoted to synonyms, notes on taxonomy, nomenclature, chromosome numbers and others items.
Species of Gracilaria in the western Pacific and the southeastern Asia are reviewed, giving 58 species and 4 varieties. A new subgenus, Hydropuntia is established and a list of the species and distribution in this region as well as a key to the species is provided.
The importance and abundance of cryptic species among invertebrate taxa is well documented. Nowadays, taxonomic, phylogenetic and conservation biological studies frequently use molecular markers to delineate cryptic taxa. Such studies, however, often face the problem of the differential resolution of the molecular markers and techniques involved. This issue is explored in the present study of cryptic taxa within the terrestrial slug complex Arion subfuscus/fuscus in continental north-west Europe. To this end, morphological, allozyme and mitochondrial 16S rDNA sequence data have been jointly evaluated. Using allozyme data and gonad type, two distinct groups were consistently delineated, even under sympatric conditions. The 16S rDNA data strongly supported both those groups and even suggested the presence of three distinct taxa within one of them. However, in view of: (1) the allopatric distribution of three OTUs, (2) the lack of allozyme or morphological differentiation, and (3) the extremely high degree of intraspecific mtDNA variation reported in pulmonate gastropods, they are, for the time being, not regarded as valid species under the biological species concept. By means of 16S rDNA and allozyme data, the position of type and topotype material of A. subfuscus s.s. and A. fuscus relative to the newly defined OTUs was determined, thus clarifying the nomenclature of this species complex. Additionally, gonad type proved to be a useful character for distinguishing the two species in north-west Europe. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83, 23–38.
Mitochondrial control region sequences from European populations of the blue tit Parus caeruleus were used to reveal the Pleistocene history and the post-glacial recolonization of Europe by the species. The southern subspecies, P. c. ogliastrae was found to represent a stable population with isolation-by-distance structure harboring a lot of genetic variation, and the northern subspecies P. c. caeruleus a recently bottlenecked and expanded population. We suggest that after the last Ice Ages, the subspecies have colonized Europe from two different southern refuges following previously proposed general recolonization routes from the Balkans to northern and Central Europe, and from the Iberian Peninsula north- and eastwards. The two subspecies form a wide secondary contact zone extending from southern Spain to southern France.
Generic concepts in the economically important agarophyte red algal family Gracilariaceae were evaluated based on maximum parsimony, Bayesian likelihood, and minimum evolution analyses of the chloroplast-encoded rbc L gene from 67 specimens worldwide. The results confirm the monophyly of the family and identify three large clades, one of which corresponds to the ancestral antiboreal genera Curdiea and Melanthalia, one to Gracilariopsis, and one to Gracilaria sensu lato, which contains nine distinct independent evolutionary lineages, including Hydropuntia. The species currently attributed to Hydropuntia comprise a single well-supported clade composed of two distinct lineages. The two most basal clades within Gracilaria sensu lato deserve generic rank: a new genus centered around G. chilensis Bird, McLachlan et Oliveira and G. aff. tenuistipitata Chang et Xia and a resurrected Hydropuntia encompassing primarily Indo-Pacific (G. urvillei [Montagne] Abbott, G. edulis [S. Gmelin] P. Silva, G. eucheumatoides Harvey, G. preissiana [Sonder] Womersley, and G. rangiferina [Kützing] Piccone) and western Atlantic species (G. cornea J. Agardh, G. crassissima P. et H. Crouan in Mazé et Schramm, G. usneoides [C. Agardh] J. Agardh, G. caudata J. Agardh, and G. secunda P. et H. Crouan in Mazé et Schramm). Cystocarpic features within the Gracilaria sensu lato clades appear to be more phylogenetically informative than male characters. The textorii-type spermatangial configuration is represented in two distinct clusters of Gracilaria. The rbc L genetic divergence among the Gracilariaceae genera ranged between 8.46% and 16.41%, providing at least 2.5 times more genetic variation than does the 18S nuclear rDNA. rbc L also resolves intrageneric relationships, especially within Gracilaria sensu lato. The current number of gracilariacean species is underestimated in the western Atlantic because of convergence in habit and apparent homoplasy in vegetative and reproductive anatomy.
Although 21 species of Gracilaria have been reported from the coast of China (Chang & Xia 1976),the taxonomy of some species has not yet been resolved because of their extreme polymorphism and the lack of authentic specimens for comparative studies. New collections of Gracilaria from south China have allowed us to assess this variability, and new materials of a few authentic specimens of G. verrucosa from England and other localities are now available for study and comparison in the Herbarium of the Institute of Oceanology.
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