A new diploid Hieracium (Asteraceae: Lactuceae) from Bulgaria

Hieracium kittanae Vladimirov, a new diploid (2 n  = 18) species restricted to a few gorges in the Central Rhodope Mountains, south Bulgaria, is described and illustrated. It occurs in crevices of limestone rock in shady to sunny places with high atmospheric humidity. Morphologically, it to some extent resembles taxa from the H. glaucinum and H. schmidtii groups, but is otherwise very distinct, without close relatives in the Rhodope and neighbouring mountains.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 143 , 213−218.     

A new diploid species of Hieracium sect. Pannosa (Asteraceae) from Bulgaria

Hieracium petrovae Vladimirov & Szeląg sp. nov. , a new diploid (2 n  = 18) species in H. sect. Pannosa Zahn, is described and illustrated from the Rhodope Mountains, South Bulgaria, and compared with related taxa. It grows in relict habitats in crevices of limestone rock together with many Balkan endemics. H. petrovae is morphologically similar to taxa from the H. pannosum , H. pilosissimum and H. heldreichii groups (collective species sensu Zahn) to some of which it is a presumed ancestral species.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 261–265.     

A taxonomic and nomenclatural note on Hieracium caesium (Asteraceae)

The only specimen suitable for typification of Hieracium caesium was discovered in UPS and is here designated as the lectotype. This name appears to have been misapplied and superfluous when originally published at specific rank, but is legitimate according to Art. 52.3. Correct names proposed for three species of the group Caesia (H. caesium = H. basifolium, H. laeticolor and H. plumbeum) are given with infraspecific variants and some more important synonyms. The names H. caesium subsp. laeticolor, H. imitans, H. caesium var. nemorum, H. plumbeum are also lectotypified. Two new combinations H. caesium var. basifolium and H. caesium var. imitans are proposed.     

Cytotype distribution and phylogeography of Hieracium intybaceum (Asteraceae)

Using flow cytometry and amplified fragment length polymorphism (AFLP), we explored the cytogeography and phylogeography of Hieracium intybaceum, a silicicolous species distributed in the Alps and spatially isolated in the Vosges Mountains and the Schwarzwald Mountains. We detected two ploidies, diploid and tetraploid, but no triploid or mixed‐ploidy populations. Whereas diploids are sexual and distributed all across the Alps, tetraploids are apomictic and seem to be confined to the western Alps and the Vosges. We detected a low level of genetic variation. Bayesian clustering identified four clusters/genetic groups, which are partly congruent with the ploidal pattern. The first two groups consisting exclusively of diploids dominate the whole distribution range in the Alps and show east–west geographical separation with a diffuse borderline running from eastern Switzerland to the eastern part of North Tyrol. The third genetic group lacks a defined geographical range and includes diploid and tetraploid plants. The last genetic group comprises tetraploid plants in the French Alps and the Vosges. We suppose that diploids colonized the deglaciated areas from source populations most likely located mainly in the southern part of the recent distribution range and occasionally also in the western Alps. Gene flow and further differentiation likely took place. Apomictic tetraploids most likely originated in the western Alps or in the refugium at the south‐western foot of the Alps. Their rather limited geographical range (partly contrasting with the theory of geographical parthenogenesis) can be explained by their rather recent origin. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 487–498.     

Lectotypification of names of south Swedish Hieracium species (Asteraceae)

Ninety-six south Swedish taxa in Hieracium L. sect. Hieracium and H. sect Vulgata (Griseb.) Willk. & Lange are lectotypified. The authorship of each name is analysed and the identity and synonomy of some dubious taxa are discussed.-Flora Nordica Note no. 24     

Eight new species of Hieracium sect. Tridentata (Asteraceae) from southern and northern Sweden

Eight new species of Hieracium sect. Tridentata, namely H. antrorsum, H. quercifolium, H. stenianum, H. vestrogothicum, and H. vetlandaënse are described from the Götaland region (southern Sweden), H. grothii from Norrbotten in the Norrland region (northeast Sweden), and H. sparsifolium var. suppansum Johanss. and H. adampliatum var. pilosius Ohlsén are raised to specific rank as H. suppansum and H. gothiciferum respectively.     

Genome size in Hieracium subgenus Hieracium (Asteraceae) is strongly correlated with major phylogenetic groups

Background and Aims

Hieracium subgenus Hieracium is one of the taxonomically most intricate groups of vascular plants, due to polyploidy and a diversity of breeeding systems (sexuality vs. apomixis). The aim of the present study was to analyse nuclear genome size in a phylogenetic framework and to assess relationships between genome size and ploidy, breeding system and selected ecogeographic features.

Methods

Holoploid and monoploid genome sizes (C- and Cx-values) of 215 cultivated plants from 89 field populations of 42 so-called ‘basic’ Hieracium species were determined using propidium iodide flow cytometry. Chromosome counts were available for all analysed plants, and all plants were tested experimentally for their mode of reproduction (sexuality vs. apomixis). For constructing molecular phylogenetic trees, the external transcribed spacer region of nuclear ribosomal DNA was used.

Key Results

The mean 2C values differed up to 2·37-fold among different species (from 7·03 pg in diploid to 16·67 in tetraploid accessions). The 1Cx values varied 1·22-fold (between 3·51 and 4·34 pg). Variation in 1Cx values between conspecific (species in a broad sense) accessions ranged from 0·24% to 7·2%. Little variation (not exceeding the approximate measurement inaccurracy threshold of 3·5%) was found in 33 species, whereas variation higher than 3·5% was detected in seven species. Most of the latter may have a polytopic origin. Mean 1Cx values of the three cytotypes (2n, 3n and 4n) differed significantly (average of 3·93 pg in diploids, 3·82 pg in triploids and 3·78 pg in tetraploids) indicating downsizing of genomes in polyploids. The pattern of genome size variation correlated well with two major phylogenetic clades which were composed of species with western or eastern European origin. The monoploid genome size in the ‘western’ species was significantly lower than in the ‘eastern’ ones. Correlation of genome size with latitude, altitude and selected ecological characters (light and temperature) was not significant. A longitudinal component was only apparent for the whole data set, but absent within the major lineages.

Conclusions

Phylogeny was the most important factor explaining the pattern of genome size variation in Hieracium sensu stricto, species of western European origin having significantly lower genome size in comparison with those of eastern European origin. Any correlation with ecogeographic variables, including longitude, was outweighed by the divergence of the genus into two major phylogenetic lineages.Key words: Apomixis, chromosome numbers, Compositae, genome size, hawkweeds, Hieracium subgenus Hieracium, mode of reproduction, nuclear DNA content, phylogeny, polyploidy     

Hieracium busambarense,a new species of the sect. Grovesiana (Asteraceae) from Sicily (Italy)

Hieracium busambarense (Asteraceae), a new species from calcareous-dolomite cliffs of Rocca Busambra (western Sicily, Italy) is described and illustrated here.     

A revision of Hieracium (Asteraceae) in Norrbotten,northeastern‐most Sweden,revealed seven new species

The large quantity of material of Hieracium sectt. Hieracium, Vulgata, Bifida and Oreadea collected during the recently completed floristic inventory of the northeastern most Swedish province of Norrbotten has been revised. The number of species known from this previously badly under‐collected province hereby increased from 27 to 64, and seven species new to science were revealed. A diagnostic key to all 64 species is provided and H. alces T. Tyler, H. hystrix T. Tyler, H. larsii‐levii T. Tyler, H. pseudopsepharum T. Tyler, H. stenbergii T. Tyler, H. taedum T. Tyler and H. vexillatum T. Tyler are described anew.     

Pollen and chromosome studies in Hieracium sect. Alpestria (Asteraceae)

Potential pollen viability has been investigated in British apomictic Hieracium section Alpestria and related species using Alexander's Stain. New and existing chromosome counts are given. Some species produced no pollen, others varied in the amount they produced, and a few species consistently produced reasonable quantities. The three triploid section Alpestria species produced very little or no pollen, whilst the amount produced by the tetraploids varied widely. Section Alpestria species had significantly lower pollen viability than the non‐section Alpestria species. The generally low pollen production in most species of section Alpestria is consistent with them being of hybrid origin.     

On Hieracium incurrens (Asteraceae) and similar species in central Sweden

Hieracium incurrens Saelan ex Norrl., originally described from Finland, has been reported from Sweden several times and independently by different authors. Still, however, its presence in Sweden has remained dubious and it has become obvious that the different reports are referable to different taxa and the name has thus been, at least partially, misapplied. In the present study, all Swedish material and putative taxa that have been suggested to belong to H. incurrens , as well as some additional closely similar taxa, is critically compared with authentic material of the latter from Finland. It is concluded that H. incurrens do indeed occur in central Sweden, namely in the eastern coastal provinces closest to Finland. However, the relevant material has mostly been referred to H. longilingua Johanss., which is here considered to be a later synonym of H. incurrens. Material previously referred to H. incurrens from other parts of Sweden does, however, represent other taxa. Five accepted species of this affinity are described and discussed in some detail and one species, viz. H. oestmanii T. Tyler is described anew. In addition, the unrelated species H. arnoldii T. Tyler is described anew based on material from the provinces of Hälsingland and Medelpad.     

Hieracium vierhapperi (Asteraceae) a new species to the Carpathians, with some remarks on its origin

Hieracium vierhapperi (Zahn) Szeląg, known so far only from the Alps, was discovered in the Nízke Tatry Mts in Slovakia, as a new species to the Carpathians. Diagnostic characters, illustration and distribution as well as ecology of H. vierhapperi in the Nízke Tatry Mts are given. A key to distinguish H. vierhapperi from the morphologically related species is added. The Carpathian plants are tetraploid (2n = 36) and reproduce apomictically. The origin of H. sect. Cernua R. Uechtr in the Western Carpathians is briefly discussed.     

Seven new species of Hieracium sect. Tridentata (Asteraceae) from Götaland,southern Sweden

Six new species of Hieracium sect. Tridentata, viz. H. piranhae, H. xanthochlorum, H. bertilssonii, H. erectiramum, H. rigescoides and H. subpardalinum are described from the Götaland region, southern Sweden and H. gothicum var. blekingense is raised to specific rank as H. blekingense.     

Ploidy level analysis of apomictic Hieracium (Asteraceae) reveal unexpected patterns and variation

The DNA ploidy level of 673 accessions belonging to 238 species of Hieracium have been analyzed by flow cytometry. 222 of the species were of Scandinavian origin as members of the exclusively apomictic H. sectt. Bifida, Hieracium, Oreadea, Tridentata and Vulgata. For the overwhelming majority of the species, the ploidy level (or chromosme number) has never been investigated before. Approximately 50% of the Scandinavian species, previously believed to be exclusively triploid, were found to be tetraploid. In addition, two pentaploid samples, viz. H. intermarginatum Johanss. & Sam. from Sweden and H. cf. plumbeum Blytt & Fr. from Germany, were found. Although two or more accessions from geographically remote sites were analyzed for approximately 50% of the Scandinavian species, only 2 (<2%) taxonomically undisputed species were found to consist of plants with more than one ploidy level. An intriguing pattern was revealed among Scandinavian members of H. sectt. Bifida and Vulgata when ploidy level and morphometric variation was compared, viz. the most typical or extreme representatives of these sections were found to be exclusively triploid whereas tetraploids dominate among species with intermediate morphology and among species morphologically intermediate between these sections and H. sect. Hieracium. This pattern may indicate that the tetraploids, which tend to have mainly northern distributions, have originated as the result of rare sexual hybridizations between triploid members of different sections, plausibly during or after the northward migration of the parental linages after the last glaciation. The results are believed to be highly relevant for understanding the processes of evolution and speciation within the predominantly apomictic genus Hieracium, but it is emphazised that additional data from e.g. molecular markers and pollen viability analysis are needed before any trustworthy conclusions can be made as far as evolutionary processes are concerned.     

Reproductive strategy and population variability in the facultative apomict Hieracium pilosella (Asteraceae)

Molecular studies of apomictic plant species often detect more genotypic variation than predicted from their assumed reproductive mode. The two most commonly invoked mechanisms to explain these high levels of variation are recombination, via facultative sexuality, and mutation. The potential for sexual reproduction in the facultative apomict Hieracium pilosella (Asteraceae) was determined at three field sites by artificially pollinating with the closely related, but morphologically distinct, H. aurantiacum. The level of genotypic variation at the three sites was recorded using inter-simple sequence repeats (ISSRs). There was a significant, positive relationship between the measured potential for sexual reproduction and population genotypic variability, indicating that sex has played a role in the structuring of these populations; however, a causal relationship cannot be stated because of the use of regression. We also applied the recently developed method of compatibility analysis. Compatibility analysis can determine, using the occurrence of "character incompatibilities," whether patterns of variation observed in populations are most parsimoniously explained by mutation or recombination. Compatibility analysis also indicated that sexual reproduction had played a role in generating genotypic diversity in these populations. Combining these different types of data may give a greater understanding of the potential for the generation of genotypic diversity in facultative apomictic populations.     

Genetic structure of the rare and endangered Hieracium wiesbaurianum group (Asteraceae) in Bavaria

The rare and endangered Hieracium wiesbaurianum species group shows a scattered relictual distribution in Bavaria. Recently, a couple of populations were discovered which clearly differ from all other populations. If these must be considered as taxonomically independent units, they would be of crucial conservation interest, because of the sole responsibility that Bavaria has for these worldwide endemics. We therefore analysed the genetic structure of H. wiesbaurianum in a comparative approach. Our analysis comprised 37 populations of 13 taxa of H. wiesbaurianum, H. bifidum and H. laevigatum, including three potentially new taxa. We applied amplified fragment length polymorphism (AFLP) analysis and observed only limited genetic variation within populations and taxa. Nevertheless, each studied individual exhibited a unique genotype. An analysis of molecular variance revealed high levels of genetic variation between taxa, but populations were genetically less different. The clear genetic differentiation between the studied taxa was supported by neighbor‐joining cluster analyses and principal coordinate analyses in which every individual was clearly assigned to its respective taxon. The three potentially new taxa were genetically as well differentiated as the other taxa included in our study. This supports the assumption that they should be treated as taxonomically independent units of high conservation interest. Therefore, the genetic analysis confirmed the morphologically based classification of the studied Hieracium taxa. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 112–123.     

木犀科丁香属的一个新等级和六个名称的模式指定

在居群取样、标本查阅、性状分析和多变量分析的基础上, 提出了丁香属Syringa一个新等级和一个新异名: 辽东丁香S. wolfii C. K. Schneid.被处理为红丁香的亚种S. villosa ssp. wolfii而不是垂丝丁香的亚种S. reflexa ssp. wolfii, 并且其后选模式被指定。同时还指定了五个异名的后选模式, 它们是S. bretschneiderii、S. emodi var. rosea、S. villosa var. hirsuta、S. formosissima和S. robusta。     

Patterns of morphometric variation and a new supraspecific classification of apomictic taxa of Hieracium (Asteraceae) from Denmark and southern Sweden

Patterns of variation among all micro-species of Hieracium sect. Hieracium and H. sect. Vulgata known from Denmark and southern Sweden are investigated. Forty-three, possibly independent morphological characters are used. Significant correlations were revealed among the majority of the characters. Multivariate analyses did not reveal any discontinuities in the variation or any discrete groups of species. However, there were obvious correlations between previous taxonomic classifications and the result of the multivariate analyses. Based on the statistical analyses, three sections and 38 informal species aggregates are recognized. H. sect. Bifidum T. Tyler is described anew. The characters that turned out to be most influential in the multivariate analyses, and thus most important for the classification, were the distribution of stellate tomentum on the phyllaries, the amount of glandular hairs and the amount and pigmentation of simple hairs on the phyllaries, the shape of the leaf-base and the regularity of the leaf dentation. The evolution of the group and the taxonomic treatment is thoroughly discussed in the light of the results.     

A new species of Centaurea (Asteraceae) from Sicily

A new species of Centaurea, Centaurea sicana , endemic to Sicily, is described. This new taxon is close to Centaurea parlatoris and Centaurea giardinae (Sect. Dissectae), the former occurring at Palermo and in the Madonie Mountains, while the latter occurs on the Etna volcano. The new species has so far been found only on the Sicani Mountains, a limestone mountain range in western Sicily, while the related species occur in the surrounding mountains. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 785–788.     

A new species of Pleiotaxis (Asteraceae) from Angola

A new species from Angola, Pleiotaxis angolensis (tribe Mutisieae, Asteraceae), is described. We detail the principal differences from the most similar taxon, Pleiotaxis subscaposa .