Silene Sect Research Articles

Convergence without divergence in North American red-flowering Silene.

Combinations of correlated floral traits have arisen repeatedly across angiosperms through convergent evolution in response to pollinator selection to optimize reproduction. While some plant groups exhibit very distinct combinations of traits adapted to specific pollinators (so-called pollination syndromes), others do not. Determining how floral traits diverge across clades and whether floral traits show predictable correlations in diverse groups of flowering plants is key to determining the extent to which pollinator-mediated selection drives diversification. The North American Silene section Physolychnis is an ideal group to investigate patterns of floral evolution because it is characterized by the evolution of novel red floral color, extensive floral morphological variation, polyploidy, and exposure to a novel group of pollinators (hummingbirds). We test for correlated patterns of trait evolution that would be consistent with convergent responses to selection in the key floral traits of color and morphology. We also consider both the role of phylogenic distance and geographic overlap in explaining patterns of floral trait variation. Inconsistent with phenotypically divergent pollination syndromes, we find very little clustering of North American Silene into distinct floral morphospace. We also find little evidence that phylogenetic history or geographic overlap explains patterns of floral diversity in this group. White- and pink-flowering species show extensive phenotypic diversity but are entirely overlapping in morphological variation. However, red-flowering species have much less phenotypic disparity and cluster tightly in floral morphospace. We find that red-flowering species have evolved floral traits that align with a traditional hummingbird syndrome, but that these trait values overlap with several white and pink species as well. Our findings support the hypothesis that convergent evolution does not always proceed through comparative phenotypic divergence, but possibly through sorting of standing ancestral variation.

Convergent Morphological Evolution in Silene Sect. Italicae (Caryophyllaceae) in the Mediterranean Basin.

Recent divergence can obscure species boundaries among closely related taxa. Silene section Italicae (Caryophyllaceae) has been taxonomically controversial, with about 30 species described. We investigate species delimitation within this section using 500 specimens sequenced for one nuclear and two plastid markers. Despite the use of a small number of genes, the large number of sequenced samples allowed confident delimitation of 50% of the species. The delimitation of other species (e.g., Silene nemoralis, S. nodulosa and S. andryalifolia) was more challenging. We confirmed that seven of the ten chasmophyte species in the section are not related to each other but are, instead, genetically closer to geographically nearby species belonging to Italicae yet growing in open habitats. Adaptation to chasmophytic habitats therefore appears to have occurred independently, as a result of convergent evolution within the group. Species from the Western Mediterranean Basin showed more conflicting species boundaries than species from the Eastern Mediterranean Basin, where there are fewer but better-delimited species. Significant positive correlations were found between an estimation of the effective population size of the taxa and their extent of occurrence (EOO) or area of occupancy (AOO), and negative but non-significant correlations between the former and the posterior probability (PP) of the corresponding clades. These correlations might suggest a lower impact of incomplete lineage sorting in species with low effective population sizes and small distributional ranges compared with that in species inhabiting large areas. Finally, we confirmed that S. italica and S. nemoralis are distinct species, that S. nemoralis might furthermore include two different species and that S. velutina from Corsica and S. hicesiae from the Lipari Islands are sister species.

The Taxonomic Position of Silene Multinervia (Caryophyllaceae), Endemic to California and Northwestern Mexico, and Description of Section Californicae, sect. nov.

Molecular analyses and cytological data have shown that Silene multinervia, which has always been placed in section Conoimorpha and often regarded as a heterotypic synonym of S. coniflora, is a separate taxon in a distinct clade. A comparison between S. multinervia and the members of section Conoimorpha is provided, showing that the species can be distinguished by both vegetative (plant height) and reproductive (flower number per inflorescence, calyx vein number, calyx length, petal apex shape, fruit length, carpophore length, and seed diameter) characters. Cytological, molecular, and morphological evidence support recognition of S. multinervia as a member of a new section endemic to southwestern California and northwestern Mexico (Baja California). Therefore, Silene sect. Californicae, sect. nov. (type: S. multinervia) is here proposed.

Phylogeny and species delimitation in Silene sect. Arenosae (Caryophyllaceae): a new section.

A putatively monophyletic group of annual Silene species is revised taxonomically and described as the new section S. sect. Arenosae. The species of this section were previously treated as a part of a widely circumscribed and polyphyletic S. sect. Rigidulae. Silene sect. Arenosae as circumscribed here consists of nine species. Members of the section show a predominantly E Mediterranean to SW Asian distribution pattern from Turkey southward to Egypt and eastward to Iran and Pakistan, although most of the species have a limited distribution range. The species of S. sect. Arenosae are characterized by narrowly lanceolate calyx teeth, which are often highly polymorphic, and lanceolate to oblanceolate (non-spathulate) basal leaves. The provided taxonomic revision is based on morphological characters and supported by phylogenetic analyses of two nuclear loci (nrITS and an intron of the RPB2 gene) and one chloroplast locus (the intron of the rps16 gene). The species descriptions are formalized using a novel implementation of the Prometheus Description Model.

<p><strong>Phylogenetic relationships of <em>Silene</em> sections <em>Lasiostemones</em> and <em>Sclerocalycine</em> (Caryophyllaceae) in Iran</strong></p>

A phylogenetic study of Silene sect. Lasiostemones and sect. Sclerocalycine in Iran is presented. A total of 72 accessions (43 of which obtained from GenBank) were analyzed using nuclear ITS and chloroplast rps16 markers. It was shown that sect. Lasiostemones is not a monophyletic group, including members which would belong to sect. Sclerocalycine (i.e. S. tenella, S. longipetala, S. lasiantha, S. marschallii, S. propinqua) and sect. Siphonomorpha (i.e. S. ghahremaninejadii, S. shahrudensis, S. saxatilis, S. ruprechtii, S. parrowiana).

Silene sunhangii (Caryophyllaceae), a new species from China.

Silene sunhangii, a new species of Caryophyllaceae known from only three populations in Hubei and Hunan provinces of central China, is described. Both morphological and molecular data were used to assess the taxonomic status and relationships of this species. Morphologically, S. sunhangii is most similar to S. platyphylla Franch. from which it differs most readily in having 3-veined elliptical leaves without pubescence, tasseled catacorolla, pale purple to red petals without a linear lobe or narrow tooth and lanceolate, bifid to one third. A phylogenetic analysis based on nuclear ITS region identified the new species as a well-supported, independent lineage. Our new species is nested within a grade that encompasses species representing a polyphyletic Silene sect. Physolychnis (Benth.) Bocquet. Both the genetic and morphological data support the recognition of Silene sunhangii as a distinct species, although there is inconsistency between these two datasets as to the relationships of the new species.

<p><strong>Notes on the genus <em>Silene</em> (Caryophyllaceae, Sileneae) in Iran</strong></p>

Two new species―Silene orientoalborzensis and S. circumcarmanica―are here described from Northeast and South Iran, respectively. They belong to Silene subg. Silene sect. Auriculatae which is the largest section of the genus in W-Asia. A specimen from center of Iran, which was identified erroneously as S. atocioides, is revised and identified as S. pendula which represents a new record for the Iranian flora. S. simsii is proposed as a nomen novum for Cucubalus multifidus.

Whole Plastome Sequencing Within Silene Section Psammophilae Reveals Mainland Hybridization and Divergence With the Balearic Island Populations.

Reconstructing the phylogenetic relationships within Caryophyllaceae tribe Sileneae has been obscured by hybridization and incomplete lineage sorting. Silene is the largest genus in the Caryophyllaceae, and unraveling its evolutionary history has been particularly challenging. In order to infer the phylogenetic relationships among the five species in Silene section Psammophilae, we have performed a genome skimming approach to acquire the complete plastid genome (cpDNA), nuclear ribosomal cistron (nrDNA), and partial mitochondrial genome (mtDNA). We have included 26 populations, representing the range of each species' distribution. This section includes five morphologically similar species endemic to the Iberian Peninsula and Balearic Islands (Ibiza and Formentera), yet some of them occupy distinct edaphic habitats (e.g. maritime sands, calcareous sandstones). In addition to phylogeographic analyses, genetic structuring using the chloroplast data set was inferred with Discriminant Analysis of Principal Components (DAPC), analyses of molecular variance (AMOVA), and a partial Mantel test. Reference-guided assembly of 50 bp single-end and 250 bp paired-end Illumina reads produced the nearly complete cpDNA genome (154 kbp), partial mtDNA genome (from 81 to 114 kbp), and the nrDNA cistron (6.4 kbp). Selected variable regions of the cpDNA and mtDNA assemblies were confirmed by Sanger sequencing. Phylogenetic analyses of the mainland populations reveal incongruence among the three genomes. None of the three data sets produced relationships consistent with taxonomy or geography. In contrast, Silene cambessedesii, present in the Balearic Islands, is the only species that forms a strongly supported monophyletic clade in the cpDNA genome and is strongly differentiated with respect to the remaining taxa of the Iberian Peninsula. These results contrast with those obtained for mainland populations. Across the entire analysis, only one well-supported mainland clade of Silene littorea and Silene stockenii emerges from the southern region of the Iberian Peninsula. DAPC and AMOVA results suggest the absence of genetic structure among mainland populations of Silene section Psammophilae, whereas partial Mantel test discarded spatial correlation of genetic differentiation. The widespread incongruence between morphology-based taxonomic boundaries and phylogeography suggests a history of interspecific hybridization, in which only a substantial geographic barrier, like isolation by the Mediterranean Sea, was sufficient to create and maintain species boundaries in Silene section Psammophilae.

On the taxonomic identity and status of 'Silene sericea' var. 'balearica' (sect. 'Dipterosperma', Caryophyllaceae)

This paper presents a re-evaluation of the taxonomic relationships of Silene sericea var. balearica based on morphological features Critical examination of herbarium specimens (including type material) and living plants has shown that S. sericea var. balearica should be recognized at species level. Therefore, the new name, Silene migjornensis, is proposed to designate the endemic species growing on maritime sands in southern Mallorca (Balearic Islands, Spain). This taxon is described, illustrated and compared with its morphologically closest relatives from Silene sect. Dipterosperma.

Evolution of sex determination and heterogamety changes in section Otites of the genus Silene

Switches in heterogamety are known to occur in both animals and plants. Although plant sex determination systems probably often evolved more recently than those in several well-studied animals, including mammals, and have had less time for switches to occur, we previously detected a switch in heterogamety in the plant genus Silene: section Otites has both female and male heterogamety, whereas S. latifolia and its close relatives, in a different section of the genus, Melandrium (subgenus Behenantha), all have male heterogamety. Here we analyse the evolution of sex chromosomes in section Otites, which is estimated to have evolved only about 0.55 MYA. Our study confirms female heterogamety in S. otites and newly reveals female heterogamety in S. borysthenica. Sequence analyses and genetic mapping show that the sex-linked regions of these two species are the same, but the region in S. colpophylla, a close relative with male heterogamety, is different. The sex chromosome pairs of S. colpophylla and S. otites each correspond to an autosome of the other species, and both differ from the XY pair in S. latifolia. Silene section Otites species are suitable for detailed studies of the events involved in such changes, and our phylogenetic analysis suggests a possible change from female to male heterogamety within this section. Our analyses suggest a possibility that has so far not been considered, change in heterogamety through hybridization, in which a male-determining chromosome from one species is introgressed into another one, and over-rides its previous sex-determining system.

Origin and Diversification of South American Polyploid Silene Sect. Physolychnis (Caryophyllaceae) in the Andes and Patagonia.

The Andes are an important biogeographic region in South America extending for about 8000 km from Venezuela to Argentina. They are – along with the Patagonian steppes – the main distribution area of ca. 18 polyploid species of Silene sect. Physolychnis. Using nuclear ITS and plastid psbE-petG and matK sequences, flow cytometric ploidy level estimations and chromosome counts, and including 13 South American species, we explored the origin and diversification of this group. Our data suggest a single, late Pliocene or early Pleistocene migration of the North American S. verecunda lineage to South America, which was followed by dispersal and diversification of this tetraploid lineage in the Andes, other Argentinian mountain ranges and the Patagonian steppes. Later in the Pleistocene South American populations hybridized with the S. uralensis lineage, which led to allopolyploidisation and origin of decaploid S. chilensis and S. echegarayi occurring at high elevations. Additionally, we show that the morphological differentiation in leaf shape correlated with divergent habitats (high elevation Andes vs. lower elevation Patagonian steppes) is also supported phylogenetically, especially in the ITS tree. Lastly, the species boundaries among the narrow-leaved Patagonian steppe species are poorly resolved and need more thorough taxonomic revision.

Silene nemrutensis (Caryophyllaceae), a new species from south-eastern Anatolia

A new perennial species, Silene nemrutensis (Silene sect. Spergulifoliae, Caryophyllaceae), is described and illustrated from SE-Anatolia. A macromorphological comparison with the similar species S. arguta is given as well as the ultrastructure of the seeds and pollen grains. Original photographs, geographical distribution, habitat and IUCN conservation status are also provided.

Silene konuralpii (Sect. Spergulifoliae, Caryophyllaceae), a new species from eastern Anatolia

A new perennial species, Silene konuralpii sp. nov. (Silene sect. Spergulifoliae) is described and illustrated from eastern Anatolia. A momorphological comparison with the similar species S. stenobotrys, S. spergulifolia, and S. surculosa is given as well as the ultrastructure of the leaf, seed and pollen grain. Original drawings and photographs, distribution map, notes on ecology, and IUCN conservation status are also provided.

A Critical Revision ofSileneSect.Holopetalae(Caryophyllaceae) in China

Silene sect. Holopetalae is represented by five species in China, of which a synopsis with updated descriptions and distribution data with an identification key is provided. Silene holopetala is a synonym of S. sibirica, S. pseudotenuis is a synonym of S. kungessana, and recently described S. langshanensis is hereby reduced to the synonym of S. gubanovii. Silene orientalimongolica is not a member of S. sect. Holopetalae but the correct name for S. linnaeana. A new combination, S. sect. Sibiricae (Devyatov & V.N. Tikhom.) Lazkov & Sennikov is proposed to classify this species in Silene. The Chinese records of S. scabrifolia (syn. S. komarovii) belong to S. sibirica or S. gebleriana, and the records of S. holopetala are referable to S. pseudoholopetala. A new combination, S. sibirica var. holopetala (Bunge) Lazkov, is proposed for a variant of S. sibirica with a pubescent calyx. The distribution of S. gubanovii is presented on a map. With these corrections, the total number of species in Silene sect. Holope...

Silene miksensis (Caryophyllaceae), a new species from eastern Anatolia

A new perennial species, Silene miksensis (Silene sect. Pinifolia, Caryophyllaceae), is described and illustrated from eastern Anatolia, Turkey. A morphological comparison with the morphologically similar species is given as well as the ultrastructure of the seed and pollen grains. S. miksensis is assested as a Critically Endangered species according to IUCN [criterion B2ab (iii)].

Silene langshanensis(Caryophyllaceae), a New Species from Inner Mongolia, China

Silene langshanensis L.Q. Zhao, Y.Z. Zhao & Z.M. Xin sp. nova (Caryophyllaceae), is described and illustrated from Inner Mongolia, China. It appears to be most closely related to S. scabrifolia of Silene sect. Holopetalae. Silene langshanensis can be distinguished by the basally pubescent carpophore, petals with obtuse auricles, stems and leaves with dense, short hairs, and by the glabrous calyx.

A new section of Silene (Caryophyllaceae) including a new species from South Anatolia, Turkey

Silene section Cryptoneurae (Caryophyllaceae) and S. ertekinii from Western Antalya, Turkey, are described as new taxa on the basis of morphological and molecular investigations. Nuclear ITS and chloroplast rps16 DNA sequences clearly support the recognition of the new section. Inclusiveness and characterization of the new section is discussed and described, and a key for the included species is provided. Diagnostic characters of the new species S. ertekinii are given and its relation to the other species of the section is discussed.

Silene peloritana (Caryophyllaceae) a new species from Sicily

Silene peloritana is described and illustrated as a narrow endemic circumscribed to Mt. Scuderi, an isolated peak of the Peloritani range (NE Sicily). The new species, belonging to S. sect. Dipterosperma, is a small therophyte growing on cacuminal carbonatic stands. It is well differentiated from the other Sicilian species of this section for its small size, shorter lower internodes, bracts and calyx teeth, petal lobes obovate, coronal scales purplish, and anthers pinkish-violet. A key of the Sicilian taxa belonging to Silene sect. Dipterosperma is provided.

Silene triflora (Bornm.) Bornm. (Caryophyllaceae), a neglected species from the Central Balkans

Status of numerous taxa from Silene sect. Saxifragoideae is still taxonomically unresolved, especially in the Balkans. In 1925 Bornmüller described a taxon from northern part of the Republic of Macedonia, first as S. saxifraga var. triflora and twelve years later as a separate species S. triflora. This taxon is listed in the Flora of the Republic of Macedonia as a variety of S. saxifraga. In other regional Floras regarding the Republic of Macedonia and the Balkans it is not included at any subgeneric level, or as a synonym. Delimitation between S. triflora and S. saxifraga is discussed on the basis of multivariate analysis of morphometric and meristic characters. The most significant characters for distinguishing these two taxa are stem length, inflorescence length, longest internode length, middle leaf length and the number of flowers. Considering that it was perceived that these two taxa differ significantly only in the number of flowers, addition to the original description of S. triflora is given. A specimen designated here as lectotype is deposited in JE. Considering geographic range and the number of locations, as well as the number of mature individuals in the largest population IUCN threatened status vulnerable (VU) is proposed.

Status and conservation of Silene section Cordifolia in the Iberian Peninsula: a menaced group under global environmental change

Background: Detailed knowledge of a species' autecology as well as information on the availability of suitable habitats and the impacts of climate change on the species and its habitat are requirements for adequate conservation planning. For this purpose, species distribution modelling has been suggested as an effective tool to assess the potential geographic distributions of species under different climate scenarios. Aims: The aim of this study was to generate suitability maps and predictive maps based on scenarios of climate change to identify areas with the most value for conservation for the western Iberian endemics Silene acutifolia, S. foetida subsp. foetida and S. foetida subsp. gayana. Methods: Maxent software was used to model and predict the distribution of the species based on environmental variables under climate change scenarios. Results: Our analysis indicated that the models performed well, predicting with high accuracy the current distributions of the species. Under two scenarios of increasing CO2, the species were predicted to be susceptible to a major reduction of suitable habitat; both S. foetida subspecies were shown to be at risk of extinction. Conclusions: Our findings suggest that the inclusion of S. foetida in national conservation and long-term monitoring programmes must be considered.