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1.
An Acad Bras Cienc ; 95(2): e20191135, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36820759

RESUMEN

The monophyly of Flourensia was examined for the first time by sequencing the nuclear ITS and plastid psbA- trnH regions in 18 species of the genus, analyzing them along with representatives of the remaining genera of subtribe Enceliinae. Results showed strong evidence for the polyphyly of Flourensia identifying two well-supported groups: Flourensia, a clade from North America including the type F. laurifolia, and another clade, here designed as the new genus Austroflourensia, containing the South American species. Austroflourensia is related to the other four genera composing the subtribe Enceliinae, whereas Flourensia s.s. is sister to all of them. Austroflourensia can be mainly distinguished by having a shrubby or subshrubby habit, capitula always radiate usually arranged in weakly cymose-corymbose capitulescences, phyllaries 2-3-seriate, and disc corollas shortly dentate. This paper proposes twelve new combinations to accommodate species previously described in the genus Flourensia and provides emended descriptions of Flourensia and the new genus Austroflourensia. The illustration of the type of the new genus, a distribution map, and a key to the genera of Enceliinae are also provided.


Asunto(s)
Asteraceae , Filogenia
2.
An Acad Bras Cienc ; 94(4): e20200082, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36449890

RESUMEN

Pseudognaphalium Kirp. (Asteraceae, Gnaphalieae) consist of about 60 species mainly distributed in South, Central, and North America. As a first contribution toward a comprehensive taxonomic review of Pseudognaphalium, we perform here the first morphometric analysis of North American species, using UPGMA method for the construction of the dendrogram. Based upon these results we present a synopsis including a key to identify species and their associated synonymy. Thirty-seven species are recognized, two taxa are newly synonymized, Pseudognaphalium microcephalum under the name P. canescens and Pseudognaphalium semilanatum under the name P. semiamplexicaule, and two other names are confirmed as synonyms as previously proposed, Pseudognaphalium micradenium as a synonym of P. helleri and Pseudognaphalium crenatum as a synonym of P. viscosum. Lectotypes are newly designated for Gnaphalium beneolens, G. berlandieri (= Pseudognaphalium stramineum), Gnaphalium decurrens (= Pseudognaphalium macounii), G. leucocephalum, G. oxyphyllum, G. oxyphyllum var. semilanatum (= P. semiamplexicaule), G. semiamplexicaule, G. sulphurescens (= P. stramineum), G. thermale, and second-step lectotypifications are proposed for G. helleri and G. wrightii (= P. canescens). In addition, the first illustrations of Pseudognaphalium helleri and P. semiamplexicaule, and a colour figure of P. canescens and P. beneolens emphasizing the results of the morphometric analysis are provided.


Asunto(s)
Asteraceae , América del Norte
3.
Mol Phylogenet Evol ; 80: 43-53, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25083940

RESUMEN

A backbone phylogeny that fully resolves all subfamily and deeper nodes of Asteraceae was constructed using 14 chloroplast DNA loci. The recently named genus Famatinanthus was found to be sister to the Mutisioideae-Asteroideae clade that represents more than 99% of Asteraceae and was found to have the two chloroplast inversions present in all Asteraceae except the nine genera of Barnadesioideae. A monotypic subfamily Famatinanthoideae and tribe Famatinantheae are named herein as new. Relationships among the basal lineages of the family were resolved with strong support in the Bayesian analysis as (Barnadesioideae (Famatinanthoideae (Mutisioideae (Stifftioideae (Wunderlichioideae-Asteroideae))))). Ancestral state reconstruction of ten morphological characters at the root node of the Asteraceae showed that the ancestral sunflower would have had a woody habit, alternate leaves, solitary capitulescences, epaleate receptacles, smooth styles, smooth to microechinate pollen surface sculpturing, white to yellow corollas, and insect-mediated pollination. Herbaceous habit, echinate pollen surface, pubescent styles, and cymose capitulescences were reconstructed for backbone nodes of the phylogeny corresponding to clades that evolved shortly after Asteraceae dispersed out of South America. No support was found for discoid capitula, multiseriate involucres or bird pollination as the ancestral character condition for any node. Using this more resolved phylogenetic tree, the recently described Raiguenrayun cura+Mutisiapollis telleriae fossil should be associated to a more derived node than previously suggested when time calibrating phylogenies of Asteraceae.


Asunto(s)
Asteraceae/clasificación , Evolución Biológica , Filogenia , Asteraceae/genética , Teorema de Bayes , ADN de Cloroplastos/genética , ADN de Plantas/genética , Fósiles , Funciones de Verosimilitud , Polinización , Análisis de Secuencia de ADN
4.
Ecol Evol ; 14(6): e11470, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38826159

RESUMEN

Predation is an important ecological process that can significantly impact the maintenance of ecosystem services. In arctic environments, the relative ecological importance of predation is thought to be increasing due to climate change, partly because of increased productivity with rising temperatures. Therefore, understanding predator-prey interactions in arctic ecosystems is vital for the sustainable management of these northern regions. Network theory provides a framework for quantifying the structures of ecological interactions. In this study, we use dietary observations on mammalian and avian predators in a high arctic region, including isolated peninsulas on Ellesmere Island and north Greenland, to construct bipartite trophic networks. We quantify the complexity, specialization, and nested as well as modular structures of these networks and also determine if these properties varied among the peninsulas. Mammal prey remains were the dominant diet item for all predators, but there was spatial variation in diet composition among peninsulas. The predator-prey networks were less complex, had more specialized interactions, and were more nested and more modular than random expectations. However, the networks displayed only moderate levels of modularity. Predator species had less specialized interactions with prey than prey had with predators. All network properties differed among the peninsulas, which highlights that ecosystems often show complex responses to environmental characteristics. We suggest that gaining knowledge about spatial variation in the characteristics of predator-prey interactions can enhance our ability to manage ecosystems exposed to environmental perturbations, particularly in high arctic environments subject to rapid environmental change.

5.
Physiol Biochem Zool ; 93(3): 227-234, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32228370

RESUMEN

Reliable methods to measure stress-related glucocorticoid responses in free-ranging animals are important for wildlife management and conservation. Such methods are also paramount for our ability to improve our knowledge of the ecological consequences of physiological processes. The brown bear (Ursus arctos) is a large carnivore of ecological and cultural importance and is important for management. Here, we provide a physiological validation for an enzyme immunoassay (EIA) to quantify glucocorticoid metabolites in brown bear feces. We also provide an evaluation of the effects of sample exposure to ambient temperature on measured fecal glucocorticoid metabolite (fGCM) concentrations. We evaluated three EIA systems: a cortisol assay, an 11-oxoetiocholanolone assay, and an 11ß-hydroxyetiocholanolone assay. Of these, the cortisol assay provided the best discrimination between peak fGCM concentrations detected 1-4 d after injections of synthetic adrenocorticotrophic hormone and preinjection baseline concentrations in four individual brown bears. The time of exposure to ambient temperature had substantial but variable effects on measured fGCM concentrations, including variation both between samples from the same individual and among samples from different bears. We propose that the validated EIA system for measuring fGCM concentrations in the brown bear could be a useful noninvasive method to monitor stress in this species. However, we highlight that this method requires that fecal samples be frozen immediately after defecation, which could be a limitation in many field situations.


Asunto(s)
Heces/química , Glucocorticoides/análisis , Fisiología/métodos , Estrés Fisiológico , Ursidae/fisiología , Zoología/métodos , Animales , Animales de Zoológico/fisiología , Femenino , Masculino
6.
Ecol Evol ; 9(8): 4783-4795, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31031944

RESUMEN

Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1 km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences.

8.
Cladistics ; 3(3): 254-272, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34949042

RESUMEN

Abstract- Lucilia is a South American genus with 23 species restricted to disjunct areas in southeastern Brazil and along the Andes. Lucilia is a monophyletic group defined by the co-occurrence of six characters: herbaceous, alternate-leaved, pappus with scabrid bristles fused at the base into a ring, style-branches with sweeping hairs far down, capitula sessile, and aseptate-flagellate hairs. A dadogram is presented using 41 morphological and anatomical characters arranged into 26 transformation series. The polarity of character states was determined by outgroup comparison with the genus Berroa. The cladistic analysis showed extensive parallel evolution in a number of the more conspicuous characters and produced four unresolved trichotomies. However, basing the hierarchy of Lucilia on the branching pattern produced by cladistic analysis results in a more natural and predicitive classification. Lucilia is divided into three sections, Lucilia, Intermedieae (sect, nov), and Lucilioides [divided into two subsections, Subspicata (subsect. nov.) and Lucilioides]. The latter subsection is subdivided into two series, Lucilioides (ser. nov.) and Paralucilia. The Brazilian species of section Lucilia (acutijolia, linearifolia, ferruginea, tmentosa, recurva, nitens, and flagelliformis) form the most primitive group within the genus. The more derived species of the genus, section lucilioides (plicatifolia, catamarcensis, burkartii, subspkata, lopezmirandae, alpina, pickeringii, piptolepis, santamca, chilensis, schultzii, longifolia, radians, lehmanni, pusilla) are found in the Andes L. eriophora (section Intermedieae) from central Chile bridges these two groups. An explanation for the distribution of the genus is given, based on the ecology of the species in relation to theories of the geologic and climatic history of South America. The present pattern has been determined by the age, geographical range, and vicissitudes of the habitat in which each group occurs. In the Brazilian species group, the habitat is old, and has remained relatively stable since well before the Pleistocene. In the Andean species group, the habitat is young and has undergone numerous rapid alterations since its inception at the end of the Pliocene.

10.
Acta farm. bonaer ; 19(3): 165-84, jul.-sept. 2000. ilus, tab
Artículo en Español | LILACS | ID: lil-288960

RESUMEN

el presente trabajo representa la quinta y última parte de las compuestas medicinales de la provincia biogeográfica Pampeana (este de la Argentina, Uruguay y mitad austral de Río Grande do Sul en Brasil), ubicados en el sexto y séptimo grupos artificiales de los siete delimitados en la primera parte del trabajo. Estos grupos están caracterizados por sus capítulos con flores dimorfas o trimorfas y con papus en todas las flores o sólo en las del disco. Comprenden 48 especies y 7 variedades que pertenecen a siete tibus


Asunto(s)
Asteraceae , Argentina
11.
Acta farm. bonaer ; 19(2): 85-90, abr.-jun. 2000. ilus
Artículo en Español | LILACS | ID: lil-288966

RESUMEN

El presente trabajo presenta la cuarta parte de las compuestas medicinales de la provincia biogeográficaPampeana (este de la Argentina, Uruguay, y mitad austral de Rio Grande do sul en Brasi) ubicadas en el quinto grupo artificial de los siete delimitados en la primera parte del trabajo. Este grupo está caracterizado por sus capítulos con flores dimorfas y papusausente y comprende catorce especies y una variedad,las cuales pertencen a cuatro tribus: Anthemideae (achillea, anthemis, artemisia, matricaria, soliva y tanacetum), Calenduleae (calendula), Helenieae (flaveria) y Heliantheae (acanthospermum y Cosmos). Se brinda una clave para la determinación de las especies y, para cada una de ellas, nombre científico válido, sinónimos, nombres vulgares, distribución geográfica, usos medicinales e iconografía


Asunto(s)
Asteraceae/uso terapéutico , Calendula/uso terapéutico , Manzanilla/clasificación
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