ABSTRACTAimThe outstanding Andean biodiversity has been linked to the occurrence of evolutionary radiations that are common among high‐elevation plant lineages. One of the most iconic examples is found in the species‐rich genus Senecio, with an impressive variation in growth forms and habitat preference. Here, we use Hyb‐Seq to overcome the lack of phylogenetic resolution found in previous studies with the aim of disentangling the processes shaping Senecio's hyper‐diversity in the Andes, including the evolution of woodiness, growth form and habitat preference.LocationCentral and Northern Andes.TaxonSenecio ser. Culcitium.MethodsHyb‐Seq data for 104 accessions of Senecio were newly generated and analysed using a data analysis workflow that utilises paralogs for phylogenetic reconstruction. The robustness of the species tree under different missing data treatments was investigated, and the phylogeny was dated. The role of hybridisation in the diversification of this lineage was addressed. The evolution of morphological key features and changes in habitat preferences were evaluated. In addition, the association of these features with diversification rate heterogeneity was tested.ResultsSenecio ser. Culcitium is a monophyletic lineage, likely of a Pleistocene origin. Hybridisation, possibly promoted by altitudinal range shifts during the Pleistocene climatic oscillations, played an important role in its evolution. We found evidence for several events of south‐to‐north migration from the puna on the Central Andes to the páramo on the Northern Andes. One of these migrations to the páramo resulted in a dramatic species diversification. Habitat changes from the páramo to the montane forest occurred multiple times and were associated with growth form shifts.Main ConclusionsWith a net diversification rate of 2 species per million years, high‐elevation Andean Senecio is among the fastest diversifying lineages documented so far in the region. Frequent shifts in woodiness, growth form, and habitat played a crucial role in the diversification of this lineage.

Genus Senecio in China: A review on its traditional uses, phytochemistry, pharmacology, and toxicity.

The genus Senecio, which is a basal angiosperm group, holds significant importance for evolutionary and phylogenetic research. It is notable for possessing male meiotic characteristics that are rarely observed in most angiosperms. However, the current understanding about male meiosis in Senecio remains incomplete. Here, we traced the cell morphological characteristics of microsporogenesis, and male gametophyte development of Senecio cannabifolius was observed by transmission electron microscopy. The results showed that the microspore mother cells were surrounded by callose; the cytokinesis was simultaneous; the tetrad was tetrahedral; and the mature pollen was two-celled pollen with three germination pores. During the meiosis of microspore mother cells, there were abundant organelles in the cytoplasm at leptotene stage. Obvious and clear synaptonemal complex was found in pachytene stage. In the prophase I stage, the number of organelles in the cytoplasm decreased; the cristae of mitochondria decreased; and the electron density of plastids was low. It began to recover at the metaphase I and formed an obvious organelle band in the anaphase I, which separated the two daughter nuclei and contained abundant organelles. During this period, the organelles in the cytoplasm changed regularly, which was the phenomenon of cytoplasmic reorganization. The pollen wall was formed at the late uninucleate stage; the pollen wall was mature at the binucleate microspore stage; and the pollen has abortion phenomenon. These results for the first time revealed the ultrastructure of microspores and male gametophytes during the development of S. cannabifolius and enriched the understanding of the formation of pollen grains by microspores in Compositae plants.

Abstract The genus Werneria was first described from six species found in the northern Andes in 1818 by Karl S. Kunth. By 1970 the number of species increased to around 50. Werneria is mostly distributed in the Andean highlands with a single species, W. nubigena, reaching as far as southern Chiapas, Mexico. Today, the genus Werneria encompasses 28 species with its center of diversity located in Peru and Bolivia. It is defined, in part, by having involucral bracts fused at least halfway and lacking a well‐developed calyculus at the base of the head. Further research indicated that there was considerable variability between Werneria species, and several species were transferred into the related genera Anticona, Misbrookea, Senecio, and Xenophyllum. Recently, it has been brought to light that the type of the genus Werneria is W. rigida, an effective lectotypification made by Rockhausen that previous authors working on this group overlooked. Since W. rigida has been accepted so far as a member of the genus Xenophyllum, Rockhausen's typification has resulted in: (1) Xenophyllum a superfluous name for Werneria; (2) Werneria a name to be applied to the species treated thus far as Xenophyllum; and (3) describing the new genus Rockhausenia to place the “traditional” Werneria species. Instead of proposing to conserve the name Werneria to avoid the aforementioned undesirable disruptions in the interest of nomenclatural stability, 30 new combinations have been made. Herein, we present the first comprehensive phylogenetic study based on ITS, trnL, ndhF, matK, and psbA sequence data involving 29 out of the 51 known species of Werneria and Xenophyllum (including the monotypic genus Misbrookea). The results indicate that: (1) the treatment of Misbrookea as a distinct genus is well supported; and (2) Werneria and Xenophyllum are each clearly not monophyletic. This, in addition to the fact that there are no diagnostic morphological synapomorphies to support either of the two genera, suggests treating them as members of a single genus. Moreover, the type of W. subg. Anactis appears to be nested in the genus Senecio. The three species belonging to this subgenus are accordingly transferred to Senecio. Finally, two subgenera are here proposed for facilitating species identification: (1) W. subg. Werneria, including species previously treated under Xenophyllum; (2) W. subg. Rockhausenia comb. & stat. nov., including the “traditional” Werneria species centered around W. nubigena.

ABSTRACT Senecio madagascariensis Poiret (Asteraceae) is a target for biological control in Australia, due to substantial impacts on agriculture and native environments. Studies in the plant’s native range in South Africa prioritised the stem-boring weevil Gasteroclisus tricostalis (Thunberg) (Curculionidae) as a candidate agent. In this study, we assessed the biology and host specificity of G. tricostalis during laboratory trials conducted in both South Africa and Australia. No-choice trials in South Africa revealed that, despite oviposition on 15 non-target Senecio species (seven Australian and eight South African), there was significantly lower oviposition relative to S. madagascariensis, with no survival to pupation or adulthood on any non-target species. In contrast, no-choice tests in quarantine in Australia, recorded oviposition on 12 non-target Australian native Senecio species, with oviposition on two species not significantly different to that on S. madagascariensis. Furthermore in Australia, larvae developed to adulthood on five non-target species, in numbers that were not significantly different to S. madagascariensis. These discrepancies can mostly be explained by the lower phylogenetic distance from S. madagascariensis to the susceptible non-target species tested in Australia and, likely, optimal plant growth conditions in quarantine in two cases. Although no-choice tests are renowned for their conservative nature, preliminary paired-choice trials in both South Africa and Australia failed to demonstrate clear oviposition preferences for S. madagascariensis. These results suggest that, given the high diversity of the genus Senecio in Australia, the weevil is likely unsuitable for release and further trials were suspended.

Abstract Diatraea saccharalis Fabricius (Lepidoptera: Crambidae), known as sugarcane borer, is the most damaging pest of sugarcane (Saccharum officinarum L., Poaceae) in northwestern Argentina and it causes significant losses in sugar and ethanol production. Currently, chemical and biological controls are used, along with host plant resistance, but there is a clear trend toward adoption of integrated pest management strategies. Considering the potential environmental and health risks associated with using agrochemicals, our study focuses on utilizing bioactive natural products, specifically plant secondary metabolites. Senecio rudbeckiaefolius Meyen & Walp (Asteraceae) is a perennial shrub found in southern Peru, Bolivia, and northwestern Argentina, valued for its use in traditional medicine. The main compounds of the genus Senecio are sesquiterpenes, with some species containing pyrrolizidine alkaloids (PAs), known for their harmful effects on herbivorous insects and vertebrates. Plant extracts exhibit several modes of action, encompassing confusion, feeding deterrence, growth regulation, insecticidal, and repellent effects. Our goal was to analyze the chemical composition of an ethanolic extract (EE) of S. rudbeckiaefolius and evaluate its lethal and sublethal effects on D. saccharalis larvae. We also investigated the potential target sites affected by the ingestion of an alkaloidal fraction from the EE (AFEE) through a midgut histological study. The main secondary metabolites identified were the PAs and phenolic compounds, with the highest concentrations found in the flowers and leaves. The majority of the PAs identified were senecionine and integerrimine. Toxicity bioassays were carried out with larvae fed on a diet supplemented with an EE of S. rudbeckiaefolius. Concentration‐dependent mortality and a marked inhibition of larval growth were recorded. We described the midgut histological structure and compared it with that of AFEE‐fed larvae. Various morphological changes were observed in the intestinal epithelium, especially an increase in the number of goblet cells and pronounced acidophilic secretion in the lumen. These results suggest that the EE of S. rudbeckiaefolius could be promising for D. saccharalis control.

Species of the genus Senecio have the largest medicinal value for the Andes communities, and studies on the biological activities attributed to them are scarce. Among them, Senecio rudbeckiifolius Meyen & Walp. is used in decoction for rheumatic affection and skin allergies. The chemical composition and antioxidant activity of the leaf essential oil from plants grown in the Peruvian Andes were studied. Eighty compounds were identified in the essential oil. Monoterpene hydrocarbons had the major percentage (91.4%), followed by oxygenated monoterpenes (4.2%). The most abundant compounds were myrcene (23.4%), b-phellandrene (17.1%), sabinene (15.1%) and limonene (11.7%). In addition, the possible applicability of volatile metabolites for revealing taxonomic/evolutionary relationships among Senecio species was explored. Antioxidant activity were examined using 1,1-diphenyl-2-picryl-hydrazyl and ferric reducing antioxidant power assays. The essential oil had a moderate scavenging effect and it showed ferric reducing activity.

A species of the diverse genus Senecio (Asteraceae), originally identified as the Australian S. quadridentatus Labill. and reported naturalized in Orange and San Diego counties, California, was determined to be correctly identified as the South African Senecio angustifolius (Thunb.) Willd. True Senecio quadridentatus is confirmed to be naturalized in southern California in Santa Barbara County, both in mainland coastal regions and on Santa Rosa Island. The two species differ in plant habit (perennial herb in S. quadridentatus, shrub in S. angustifolius), leaf length (60–130 mm in S. quadridentatus, 10–35 mm in S. angustifolius), head type (disciform in S. quadridentatus, discoid in S. angustifolius), and head shape and size (involucre narrowly cylindric and 6.5–10 mm in S. quadridentatus, involucre widely cylindric and 5–6 mm in S. angustifolius). Evidence for these determinations, a description for Senecio angustifolius, and a revision to the key to Senecio in California are presented. The eradication of these exotics in natural habitats of southern California is ongoing, but further monitoring is required.

The genus Senecio is one of the largest in Asteraceae. There are thousands of species across the globe, either confirmed or awaiting taxonomic delimitation. While the species are best known for the toxic pyrrolizidine alkaloids that contaminate honeys (as bees select pollen from the species) and teas via lateral transfer and accumulation from adjacent roots of Senecio in the rhizosphere, they are also associated with more serious cases leading to fatality of grazing ruminants or people by contamination or accidental harvesting for medicine. Surprisingly, there are significantly more sesquiterpenoid than pyrrolizidine alkaloid-containing species. The main chemical classes, aside from alkaloids, are flavonoids, cacalols, eremophilanes, and bisabolols, often in the form of furan derivatives or free acids. The chemistry of the species across the globe generally overlaps with the 469 confirmed species of Africa. A small number of species express multiple classes of compounds, meaning the presence of sesquiterpenes does not exclude alkaloids. It is possible that there are many species that express the pyrrolizidine alkaloids, in addition to the cacalols, eremophilanes, and bisabolols. The aim of the current communication is, thus, to identify the research gaps related to the chemistry of African species of Senecio and reveal the possible chemical groups in unexplored taxa by way of example, thereby creating a summary of references that could be used to guide chemical assignment in future studies.

As part of ongoing studies on the genus Senecio in Chile, we here synonymize the name S. phylloleptus with S. reicheanus, as well as S. behnii with the retrieved name S. eriocladus. Furthermore, the original concept of S. coquimbensis is reestablished and its nomenclatural implications detailed. Finally, the identity and presence of S. saxicola in Chile is clarified and the new species S. ephemerus is described.

Species of the genus Senecio have been traditionally employed with medical purposes and it has been demonstrated that some of them have anti-proliferative activity on cancer-derived cell lines. In South America S. madagascariensis is one of the most important representatives of the genus. Almost all species contain pyrrolizidine alkaloids (PA), substances that can lead to hepatic damage. Thus, the aim of this work was to determine the cytotoxic activity of a low PAs extract of S. madagascariensis on a cancer-derived cell line. A chloroform extract from plant material was produced and it was demonstrated to have a PAs concentration lower than 200 μg/g (w/w). Two stock solutions were made with DMSO and acetone as solvents and were diluted in culture medium (DMEM). Cells from urinary bladder transitional cell carcinoma T24 were cultured in 96 well plates (104 cells/well) and incubated for 24 hours with dilutions of the extracts at the following concentrations, 0.5 mg/mL, 0.25 mg/mL, 0.125 mg/mL and 0.06 mg/mL. Cell viability was evaluated by the MTT colorimetric technique. Both solutions of S. madagascariensis extracts (acetone and DMSO) showed cytotoxic activity. In both cases, the degree of cytotoxicity was dependent on the concentration of the solution.

The cosmopolitan genus Senecio Linnaeus (1753: 866) is one of the most species-rich genera in Asteraceae, comprising about 1426 species (POWO 2021); the main centres of its diversity are South Africa, Chile and the Mediterranean Basin (Calvo et al. 2015). About 63 species of Senecio are known to occur in Mexico, of which 44 species are endemic to the country (Villaseñor 2016).

After the monographic revision of the genus Senecio Linnaeus (1753: 866) from Chile by Cabrera (1949), several nomenclatural adjustments were made (Jeffrey 1992, Soldano 1998, Calvo 2020, Wu et al. 2020). Herein, we point out the illegitimacy of two names that have widely been accepted in the literature dealing with Senecio in the Southern Cone of South America (Cabrera 1949, Cabrera 1971, Marticorena & Quezada 1985, Freire 2008, Freire et al. 2014, Rodríguez et al. 2018). The respective priority names are indicated. Moreover, the name S. crepidoides Philippi (1894: 252) is lectotypified.

The analysis of herbarium material of the genus Senecio from Southern Peru resulted in the identification of two new records for its Flora: Senecio behnii y Senecio ctenophyllus. Based on the examination of herbarium specimens from Chile and Peru, we provide the morphological descriptions, distribution, habitat, and a comparison with the closer species.

Thus far, the genus Senecio L. in Chile has only been thoroughly revised by the Argentinian botanist Cabrera, who published a monograph in 1949. He treated 11 names as dubious, 10 of which have remained unresolved until now. Herein, the taxonomic position of six names is elucidated, i.e., S. alsophilus Phil., S. araucanus Phil., S. leiophyllus Turcz., S. rufescens DC., S. simpsonii Phil., and S. tenuicaulis Phil. Moreover, the priority name for the illegitimate S. glaber Less. is indicated, the name S. botijae C. Ehrh. is synonymized with S. calcicola Meyen & Walp., and S. borchersii Phil. is synonymized with S. hakeifolius Bertero ex DC. The names S. araucanus, S. hakeifolius, S. leiophyllus, and S. tocornalii Phil. are lectotypified; likewise, S. alsophilus and S. simpsonii are neotypified.

1,10β- epoxy -6-oxo-furanoeremophilane 1 (21.8%) along with furanoligularenone 2 , germacrene D 3, selin-11-en-4α-ol 4 and caryophyllene oxide 5 have been identified in Senecio chrysanthemoides DC. of the Garhwal region of Himalaya at an altitude of 3600 m. 1,10β- epoxy -6-oxo-furanoeremophilane 1 has not been reported in Senecio chrysanthemoides DC. but reported in the other species of the genus Senecio. Presence of compounds 1-5 and absence of previously reported β-thujone and 6-hydroxy- p -menth-4(5)-en-3-one makes it a new chemotype within the genus Senecio . Normal 0 false false false EN-US X-NONE HI

Senecio scandens Buch.-Ham. is a crucial source of Chinese traditional medicine with antibacterial properties. In this study, we report the complete chloroplast genome sequence of S. scandens. The assembled chloroplast genome was 150,729 bp in length, containing two inverted repeated (IR) regions of 24,455 bp each, a large single-copy (LSC) region of 83,984 bp and a small single-copy (SSC) region of 17,835 bp. The genome encodes 133 genes consisting of 89 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. The overall GC content of S. scandens is 37.4%, with the highest GC content of 43% in the IR region. A total of 38 simple sequence repeats are identified in the cp genome of S. scandens. Phylogenetic analysis demonstrated a sister relationship between S. scandens and Pericallis hybrida, indicating further revisions for the genus Senecio. This work provides basic genetic resources for investigating the evolutionary status and population genetics diversities for this medicinal species.

Two major developments have made it possible to use examples of ecological radiations as model systems to understand evolution and ecology. First, the integration of quantitative genetics with ecological experiments allows detailed connections to be made between genotype, phenotype, and fitness in the field. Second, dramatic advances in molecular genetics have created new possibilities for integrating field and laboratory experiments with detailed genetic sequencing. Combining these approaches allows evolutionary biologists to better study the interplay between genotype, phenotype, and fitness to explore a wide range of evolutionary processes. Here, we present the genus Senecio (Asteraceae) as an excellent system to integrate these developments, and to address fundamental questions in ecology and evolution. Senecio is one of the largest and most phenotypically diverse genera of flowering plants, containing species ranging from woody perennials to herbaceous annuals. These Senecio species exhibit many growth habits, life histories, and morphologies, and they occupy a multitude of environments. Common within the genus are species that have hybridized naturally, undergone polyploidization, and colonized diverse environments, often through rapid phenotypic divergence and adaptive radiation. These diverse experimental attributes make Senecio an attractive model system in which to address a broad range of questions in evolution and ecology.

Current treatments for complex diseases have remarkable side effects that negatively impact patients' quality of life. Thus, natural compounds with fewer side effects represent a promising source for safe drugs. The genus Senecio is widely used in folk medicine due to its various pharmacological properties. In the present study, the total phenolic content of Senecio glaucus, which is grown in Saudi Arabia, was assessed using the Folin-Ciocalteau colorimetric method. Scavenging DPPH and ABTS assays were utilized to determine the antioxidant properties of S. glaucus fractions, and MTT assay was used to screen the cytotoxic activity of S. glaucus against various cancer cells. In addition, HPLC-UV was utilized to detect the presence of two phenolic acids, namely, vanillic acid (VA) and gallic acid (GA). Among all fractions tested, S. glaucus chloroform fraction (SGCF) yielded the highest value (125.3 mg·GA/g) in terms of total phenolic content. SGCF also exhibited the highest scavenging activities (76.7 and 74.1%) on both DPPH and ABTS assays, respectively. Similarly, SGCF also possessed the most potent cytotoxic activity against the MCF-7 cell line, with an IC50 value of 41.8 μg/ml. The validated HPLC method confirmed the presence of VA (4.8 μg/mg DW) and GA (3.9 μg/mg DW) in SGCF. Overall, our data show that S. glaucus had antioxidant and cytotoxic properties. A developed validated HPLC method which could be helpful for quantifying phenolic compounds in S. glaucus was established.

Knowledge on how life history traits affect distribution in range-restricted and endemic plants is paramount for conservation and management, particularly for threatened species. Traits relating to dispersal ability are important in the ongoing persistence of range restricted species and may present a pathway to extinction or invasion. This is evident in the highly diverse and cosmopolitan genus Senecio (Asteraceae), where both threatened and invasive species occur within Australia. In this study, propagule geometry, settling velocity and dispersal potential for two range-restricted and threatened native taxa (S. linearifolious var. dangarensis Belcher ex I.Thomps., S. spathulatus var. attenuatus I.Thomps.) are contrasted with four native taxa that occupy wider ranges (S. amygdalifolius F.Muell., S. l. var. arachnoideus I.Thomps., S. l. var. macrodontus (DC.) I.Thomps., S. pinnatifolius A.Rich. var. pinnatifolius) and one introduced, wide-ranging species (S. madagascariensis Poir.). Differences were found in settling velocity and propagule morphology across all taxa. Based on propagule morphology, S. amygdalifolius has the greatest dispersal potential, S. spathulatus var. attenuatus the smallest, whereas all other taxa were similar. Although useful, dispersal potential alone does not fully explain distributional differences between all range-restricted and widespread taxa, and close assessment of habitat attributes may be required to further elucidate dispersal limitations in some taxa.