Exploring floral morphoanatomy and embryology in wild populations of Chrysolaena flexuosa (Vernonia, Asteraceae): a contribution to understanding its ornamental potential.

Chrysolaena flexuosa (Sims.) H. Rob. is a South American species in the tribe Vernonieae, with potential ornamental value: it has attractive inflorescences, is suitable for pot cultivation, and its cypselae are useful for dried flower arrangements. Apart from studies on the growth dynamics of this species under cultivation, chromosome number, DNA content, ploidy level, size, pollen viability, and the characterization of phenotypic and genetic variability, it is noteworthy that other aspects regarding the floral architecture, reproductive mode, and gametophyte formation of C. flexuosa have not yet been studied. For this reason, our study encompasses a floral morphoanatomical survey and a comprehensive assessment of gametophyte development in the species. As a result of this study, we report new floral morphotypes, confirming that the morphological variability of the species might be greater than speculated. The morphoanatomy of the androecium and gynoecium and the male and female gametophyte developmental characteristics are uniform in all the populations studied despite the different ploidy levels. Chrysolaena flexuosa has five tetrasporangiate stamens of the dicotyledonous type of development; all the populations studied displayed a unilocular inferior ovary with a single anatropous, unitegumented, and tenuinucellar ovule. Given that all the embryo sacs observed were of the Polygonum-type development regardless of the ploidy level, we infer that the populations analyzed are fertile and undergo sexual reproduction. Our results not only contribute further research in the field of breeding systems and propagation of this species, but also promote the successful introduction of C. flexuosa to the plant ornamental market.

Phytochemical profile of different anatomical parts of jambu (Acmella oleracea (L.) R.K. Jansen): A comparison between hydroponic and conventional cultivation using PCA and cluster analysis.

Jambu [Acmella oleracea (L.) R.K. Jansen] is an edible plant with a wide range of constituents of biological interest. In this study, the chemical composition of leaves, flowers and stems of jambu cultivated in hydroponic and conventional systems was investigated. In both crop systems, the leaves showed the highest total phenolic content, total flavonoid content and in vitro antioxidant capacity. The extracts were characterized by determining 45 compounds, including phenolic acids, glycosylated flavonoids, alkamides and fatty acids, by LC-MS analysis. Of these compounds, 31 are described for the first time in this species, five of which are reported for the first time in the literature. The PCA and cluster analysis results distinguished different anatomical parts (PC1 and PC2) and cultivation systems (PC3) into well-defined groups.

Morphoanatomical and phytochemical studies for the quality control of Neurolaena lobata (L.) R.Br. ex Cass. (Asteraceae) / Estudios morfoanatomicos y fitoquimicos para el control de calidad de Neurolaena lobata (L.) R.Br. ex Cass. (Asteraceae)

Neurolaena lobata (L.) R.Br. ex Cass. (Asteraceae)Is a popular folk remedy for in Central America. The plant is of commercial value in Guatemala but so far there is not any monograph to guide regional laboratories on ensuring identity and chemical tests for this species. As identity test we here run macro and micro morphoanatomical studies of the characters of the vegetative organs. We also developed standard chemical tests for quality by both TLC and HPLC for infusions and tinctures of varying alcoholic strength. Their radical scavenging activities in DPPH and NO were also measured. Macro and micro morphoanatomical characters of the vegetative organs present a set of characteristics to facilitate the identification of dry powdered samples of this species. We developed optimal conditions for the TLC and HPLC phytochemical fingerprints of the 4 most common pharmacopoeial liquid herbal preparations from this herbal drug, namely infusion, 70%, 45% and 20% hydroalcoholic tinctures. Our work provides the Latin-American industry with a set of analyses to establish the identity and chemistry of N. lobata samples for quality control purposes.

Neurolaena lobata (L.) R.Br. ex cass. (Asteraceae) es un remedio popular popular en América Central. La planta tiene un valor comercial en Guatemala, pero hasta el momento no existe una monografía que guíe a los laboratorios regionales para garantizar la identidad y las pruebas químicas para esta especie. Como prueba de identidad proponemos estudios macro y micro morfoanatómicos de los caracteres de los órganos vegetativos. También desarrollamos pruebas químicas de calidad mediante CCF y CLAR para infusiones y tinturas de grado alcohólico variable. También se midieron sus actividades de captación de radicales en DPPH y NO. Los caracteres macro y micro morfoanatómicos de los órganos vegetativos presentan un conjunto de características para facilitar la identificación de muestras de polvo seco de esta especie. Desarrollamos condiciones óptimas para las huellas dactilares fitoquímicas de CCF y CLAR de las 4 preparaciones herbales líquidas farmacopéicas más comunes de esta droga herbal, a saber, infusión, 70%, 45% y 20% tinturas hidroalcohólicas. Nuestro trabajo proporciona a la industria latinoamericana un conjunto de análisis base para establecer la identidad y la química de las muestras de N. lobata con fines de control de calidad.

Can climate and soil conditions change the morpho-anatomy among individuals from different localities? A case study in Aldama grandiflora (Asteraceae) / Condições climáticas e de solo podem alterar a morfo-anatomia entre indivíduos de diferentes localidades? Um estudo de caso em Aldama grandiflora (Asteraceae)

Vegetative aerial organs are considerably more exposed to environmental conditions and can reflect the specific adaptations of plants to their local environment. Aldama grandiflora species are known to be widely distributed in Brazil; therefore, individuals from different populations of this species are thought to be exposed to different abiotic and biotic conditions. Several anatomical studies conducted on Brazilian Aldama species have mainly focused on the qualitative anatomical characters or traits of these species, but not on their quantitative traits. In this study, we evaluated whether climate and soil conditions can change the morphometry among individuals of A. grandiflora collected from six sites in the Goiás State, Brazil, by assessing their anatomical characters. Further, soil sampling was performed, and climate data were collected from all the six sites. The analysis indicated few statistical differences among the populations evaluated, showing that A. grandiflora presented consistent leaf and stem anatomical characteristics. The small morpho-anatomical differences found among individuals of the different populations evaluated, reflected the soil conditions in which these populations were grown. Therefore, environmental factors have a significant influence on the morpho-anatomy of Aldama grandiflora.(AU)

Os órgãos vegetativos aéreos estão consideravelmente mais expostos às condições ambientais e podem refletir as adaptações específicas das plantas ao seu habitat. A espécie Aldama grandiflora é amplamente distribuída no Brasil e, dessa forma, indivíduos de diferentes populações podem estar expostos a diferentes condições ambientais. Vários estudos anatômicos realizados com espécies brasileiras do gênero Aldama têm abordado, principalmente, as características anatômicas qualitativas dessas espécies, mas não em suas características quantitativas. Neste estudo avaliamos se as condições climáticas e do solo podem alterar a morfometria entre os indivíduos de A. grandiflora coletados em seis populações do Estado de Goiás. Foram avaliados os caracteres anatômicos foliares e caulinares, além da amostragem do solo e coleta de dados climáticos, para os seis locais. A análise indicou algumas diferenças estatísticas entre as populações avaliadas, mostrando que A. grandiflora apresentou características anatômicas foliares e caulinares bastante consistentes. As pequenas diferenças morfo-anatômicas encontradas entre indivíduos das diferentes populações avaliadas, refletiram as condições do solo nos quais essas populações se desenvolveram. Assim sendo, fatores ambientais relacionados ao clima e condições do solo têm uma influência significativa sobre a morfo-anatomia de Aldama grandiflora.(AU)

Strategies of leaf water uptake based on anatomical traits.

The ability of leaves to absorb fog water can positively contribute to the water and carbon balance of plants in montane ecosystems, especially in periods of soil water deficit. However, the ecophysiological traits and mechanisms responsible for variations in the speed and total water absorption capacity of leaves are still poorly known. This study investigated leaf anatomical attributes of seven species occurring in seasonal tropical high-altitude ecosystems (rocky outcrop and forest), which could explain differences in leaf water uptake (LWU) capacities. We tested the hypothesis that different sets of anatomical leaf attributes will be more marked in plant individuals living under these contrasting environmental conditions. Anatomical variations will affect the initial rate of water absorption and the total storage capacity, resulting in different strategies for using the water supplied by fog events. Water absorption by leaves was inferred indirectly, based on leaf anatomical structure and visual observation of the main access routes (using an apoplastic marker), the diffusion of water through the cuticle, and non-glandular or glandular trichomes in all species. The results suggest that three LWU strategies coexist in the species studied. The different anatomical patterns influenced the speed and maximum LWU capacity. The three LWU strategies can provide different adaptive advantages to adjust to temporal and spatial variations of water availability in these tropical high-altitude environments.

Flower structure and developmental stages of the capitulum of Smallanthus sonchifolius (Asteraceae): reproductive implications.

Yacon (Smallanthus sonchifolius, Asteraceae) is an ancient andean crop that has numerous dietary and medicinal properties. Morphological and anatomical features and developmental changes of the capitulum were studied. A ray floret is a pistillate, female flower, while a disc floret is a staminate male flower, and the former opens before the latter, being pseudanthium protogynous. The capitulum presents interesting attributes for pollinators such as flower structure, nectaries and pollenkitt. Gynoecial nectaries were found on undeveloped ovary in the disc floret, but not in the ray floret. Glandular trichomes were observed on the abaxial epidermis of corolla in the ray floret, but not in the disc floret. Capitulum development was divided into eight stages. Stigma receptivity varied with these stages. Pollen viability was low (15%). In accordance with low viability, pollen grains exhibit diverse sizes and shapes, reduction in length of spines, and abnormal protoplasm. Examination of ovary development in the ray floret showed that a mature ovule was formed, but fertilization did not occur. In advanced developmental stages, the capitulum showed proliferation of the endothelium, degeneration of the embryo sac, and all harvested cypselae had aborted seeds. Problems found in pollen viability and aborted cypselae could be the result of a history of vegetative propagation in the domestication process.

The origin of the bifurcating style in Asteraceae (Compositae).

BACKGROUND AND AIMS: The plant family Asteraceae (Compositae) exhibits remarkable morphological variation in the styles of its members. Lack of studies on the styles of the sister families to Asteraceae, Goodeniaceae and Calyceraceae, obscures our understanding of the origin and evolution of this reproductive feature in these groups. The aim of this work was to perform a comparative study of style morphology and to discuss the relevance of important features in the evolution of Asteraceae and its sister families. METHODS: The histochemistry, venation and general morphology of the styles of members of Goodeniaceae, Calyceraceae and early branching lineages of Asteraceae were analysed and put in a phylogenetic framework to discuss the relevance of style features in the evolution of these families. KEY RESULTS: The location of lipophilic substances allowed differentiation of receptive from non-receptive style papillae, and the style venation in Goodeniaceae and Calyceraceae proved to be distinctive. There were several stages of style evolution from Goodeniaceae to Asteraceae involving connation and elongation of veins, development of bilobation from an initially cup-shaped style, and a redistribution of the receptive and non-receptive papillae. CONCLUSIONS: These developments resulted in bifurcation in the styles of Asteraceae, with each branch face having a different function, and it is suggested here as a mechanism that promoted outcrossing, which in turn led to the great diversification in the family.

Morpho-anatomy and ontogeny of the underground system of Chrysolaena simplex (Less.) Dematt. (Asteraceae).

The occurrence of thickened underground systems in Asteraceae is widely reported in the literature. Given the great complexity of underground systems, which may originate from roots, stems, or both, morpho-anatomical analyses are essential to ensure the use of correct terminology. The goals of this study were to describe the morpho-anatomy and ontogeny, investigate the occurrence of secondary metabolites and evaluate the effects of seasonality on the underground system of Chrysolaena simplex (Less.) Dematt. Samples were studied using standard protocols of plant anatomy, scanning electron microscopy, histochemical and phytochemical. The underground system of C. simplex was categorised as a rhizophore which started from cotyledonary node. In adult individuals, with rhizophores completely developed, the primary roots degenerated and adventitious radicular systems are formed. The buds in the subterranean portions promote the rhizophore growing, and form aerial stems when exposed to light. Lipophilic droplets were evident in the parenchymatous cells of the cortex and pith, endodermis and buds. Inulin-type fructans were observed in the stem axis and buds of the rhizophore. The presence of buds, secondary metabolites and the storage of fructans and lipids in the rhizophore can be seen as adaptive traits.

Capitate glandular trichomes in Aldama discolor (Heliantheae - Asteraceae): morphology, metabolite profile and sesquiterpene biosynthesis.

The capitate glandular trichome is the most common type described in Asteraceae species. It is known for its ability to produce various plant metabolites of ecological and economic importance, among which sesquiterpene lactones are predominant. In this paper, we applied microscopy, phytochemical and molecular genetics techniques to characterise the capitate glandular trichome in Aldama discolor, a native Brazilian species of Asteraceae, with pharmacological potential. It was found that formation of trichomes on leaf primordia of germinating seeds starts between 24 h and 48 h after radicle growth indicates germination. The start of metabolic activity of trichomes was indicated by separation of the cuticle from the cell wall of secretory cells at the trichome tip after 72 h. This coincided with the accumulation of budlein A, the major sesquiterpene lactone of A. discolor capitate glandular trichomes, in extracts of leaf primordia after 96 h. In the same timeframe of 72-96 h post-germination, gene expression studies showed up-regulation of the putative germacrene A synthase (pGAS2) and putative germacrene A oxidase (pGAO) of A. discolor in the transcriptome of these samples, indicating the start of sesquiterpene lactone biosynthesis. Sequencing of the two genes revealed high similarity to HaGAS and HaGAO from sunflower, which shows that key steps of this pathway are highly conserved. The processes of trichome differentiation, metabolic activity and genetic regulation in A. discolor and in sunflower appear to be typical for other species of the subtribe Helianthinae.

Anatomy and fructan distribution in vegetative organs of Dimerostemma vestitum (Asteraceae) from the campos rupestres.

Among the compounds stored by plants, several functions are assigned to fructans, such as source of energy and protection against drought and extreme temperatures. In the present study we analyzed the anatomy and distribution of fructans in vegetative organs of Dimerostemma vestitum (Asteraceae), an endemic species from the Brazilian campos rupestres. D. vestitumhas amphistomatic and pubescent leaves, with both glandular and non-glandular trichomes. In the basal aerial stem the medulla has two types of parenchyma, which differ from the apical portion. The xylopodium has mixed anatomical origin. Interestingly, although inulin-type fructans with high degree of polymerization were found in all analyzed organs except the leaves, the highest amount and maximum degree of polymerization were detected in the xylopodium. Inulin sphero-crystals were visualized under polarized light in the medulla and in the vascular tissues mainly in the central region of the xylopodium, which has abundant xylem parenchyma. Secretory structures accumulating several compounds but not inulin were identified within all the vegetative organs. The presence of these compounds, in addition to inulin, might be related to the strategies of plants to survive adverse conditions in a semi-arid region, affected seasonally by water restriction and frequently by fire.

Morfoanatomia do eixo vegetativo aéreo de Ayapana triplinervis (Vahl) R.M. King & H. Rob. (Asteraceae) / Morphoanatomy of the vegetative aerial axis of Ayapana triplinervis (Vahl) RM King & H. Rob. (Asteraceae)

Ayapana triplinervis (Asteraceae) é uma erva medicinal da Amazônia conhecida como "Japana branca" e "Japana roxa" utilizada como tônico, digestivo, antidiarréico dentre outros. Objetivou-se caracterizar neste estudo a morfoanatomia caulinar e foliar de A. triplinervis, para corroborar se esta espécie apresenta morfotipos, além de fornecer dados para sua identificação. Amostras foram coletadas no Horto de Plantas Medicinais da Universidade Federal Rural da Amazônia e Embrapa Amazônia Oriental, analisadas morfologicamente e segundo técnicas usuais em anatomia vegetal. O caule é cilíndrico branco ou roxo, com epiderme unisseriada persistente e endoderme com bainha amilífera e estrias de Caspary. As folhas são simples, opostas, triplinervadas, com base atenuada ou decorrente. Possuem estômatos anomocíticos, cera em placas ou granular, glândulas peroladas, mesofilo dorsiventral com feixes colaterais e ductos secretores. A. triplinervis apresentou caracteres morfoanatômicos diferentes entre os tipos branca e roxa, o que possibilita a distinção dos dois morfotipos.

Ayapanatriplinervis (Asteraceae), also known as "Japana branca" and "Japana roxa" in Brazil, is a medicinal herb from the Amazon used as tonic, digestive, antidiarrheal, among others. This study aimed to characterize the morphoanatomy of the aerial vegetative axis of A. triplinervis to corroborate that this species has morphotypes, in order to provide data for their identification. Samples were collected in the Garden of Medicinal Plants of the Federal Rural University of Amazônia and Embrapa Amazônia Oriental, and they were analyzed morphologically and by the standardtechniques of plant anatomy. The stem is cylindrical, white or purple, with uniseriate epidermis, trichomes and endoderm with starch sheath and Casparian strips. The leaves are simple, opposite, with attenuate or arising basis; they have anomocytic stomata, epicuticular wax plates or granules, pearl glands, dorsiventral mesophyll with collateral vascular bundles and secretory ducts. Ayapana triplinervis showed different morphoanatomical features betweenthe white and purple types, which enablesthe distinction between the two morphotypes.

Evolutionary origin of the Asteraceae capitulum: Insights from Calyceraceae.

PREMISE OF THE STUDY: Phylogenies based on molecular data are revealing that generalizations about complex morphological structures often obscure variation and developmental patterns important for understanding the evolution of forms, as is the case for inflorescence morphology within the well-supported MGCA clade (Menyanthaceae + Goodeniaceae + Calyceraceae + Asteraceae). While the basal families share a basic thyrsic/thyrsoid structure of their inflorescences, Asteraceae possesses a capitulum that is widely interpreted as a racemose, condensed inflorescence. Elucidating the poorly known inflorescence structure of Calyceraceae, sister to Asteraceae, should help clarify how the Asteraceae capitulum evolved from thyrsic/thyrsoid inflorescences. METHODS: The early development and structure of the inflorescence of eight species (five genera) of Calyceraceae were studied by SEM, and patterns of evolutionary change were interpreted via phylogenetic character mapping. KEY RESULTS: The basic inflorescence structure of Calyceraceae is a cephalioid (a very condensed botryoid/thyrsoid). Optimization of inflorescence characters on a DNA sequence-derived tree suggests that the Asteraceae capitulum derives from a simple cephalioid through two morphological changes: loss of the terminal flower and suppression of the cymose branching pattern in the peripheral branches. CONCLUSIONS: Widely understood as a condensed raceme, the Asteraceae capitulum is the evolutionary result of a very reduced, condensed thyrsoid. Starting from that point, evolution worked separately only on the racemose developmental control/pattern within Asteraceae and mainly on the cymose developmental control/pattern within Calyceraceae, producing head-like inflorescences in both groups but with very different diversification potential. We also discuss possible remnants of the ancestral cephalioid structure in some Asteraceae.

An extinct Eocene taxon of the daisy family (Asteraceae): evolutionary, ecological and biogeographical implications.

BACKGROUND AND AIMS: Morphological, molecular and biogeographical information bearing on early evolution of the sunflower alliance of families suggests that the clade containing the extant daisy family (Asteraceae) differentiated in South America during the Eocene, although palaeontological studies on this continent failed to reveal conclusive support for this hypothesis. Here we describe in detail Raiguenrayun cura gen. & sp. nov., an exceptionally well preserved capitulescence of Asteraceae recovered from Eocene deposits of northwestern Patagonia, Argentina. METHODS: The fossil was collected from the 47·5 million-year-old Huitrera Formation at the Estancia Don Hipólito locality, Río Negro Province, Argentina. KEY RESULTS: The arrangement of the capitula in a cymose capitulescence, the many-flowered capitula with multiseriate-imbricate involucral bracts and the pappus-like structures indicate a close morphological relationship with Asteraceae. Raiguenrayun cura and the associated pollen Mutisiapollis telleriae do not match exactly any living member of the family, and clearly represent extinct taxa. They share a mosaic of morphological features today recognized in taxa phylogenetically close to the root of Asteraceae, such as Stifftieae, Wunderlichioideae and Gochnatieae (Mutisioideae sensu lato) and Dicomeae and Oldenburgieae (Carduoideae), today endemic to or mainly distributed in South America and Africa, respectively. CONCLUSIONS: This is the first fossil genus of Asteraceae based on an outstandingly preserved capitulescence that might represent the ancestor of Mutisioideae-Carduoideae. It might have evolved in southern South America some time during the early Palaeogene and subsequently entered Africa, before the biogeographical isolation of these continents became much more pronounced. The new fossil represents the first reliable point for calibration, favouring an earlier date to the split between Barnadesioideae and the rest of Asteraceae than previously thought, which can be traced back at least 47·5 million years. This is the oldest well dated member of Asteraceae and perhaps the earliest indirect evidence for bird pollination in the family.

Morfoanatomía comparativa de dos especies de Acanthospermum (ASTERACEAE) / Comparative morpho-anatomy of two species of Acanthospermum (ASTERACEAE)

RESUMEN: Para el presente trabajo se ha escogido dos especies de las plantas reportadas como antiinflamatorias, dentro del marco del Proyecto "Un aporte para el control de calidad de drogas de origen vegetal: Análisis micrográfico de drogas vegetales empleadas en la medicina popular paraguaya como antiinflamatorias y comercializadas en los mercados de Asunción, Luque, San Lorenzo, Paraguarí y Caacupé": "tapekué", Acanthospermum australe (Loef.) Kuntze y "toro rati", A. hispidum DC. (Asteraceae); con el fin de realizar la caracterización morfoanatómica foliar y caulinar de ambas especies. Los caracteres morfoanatómicos diferenciales encontrados son: A. australe; hierba decumbente o ascendente, hoja levemente pubescente, rómbico-ovada; base atenuada, corto peciolo, fruto aquenio fusiforme cubierto de espinas ganchudas; parénquima en empalizada con dos hileras de células, pelos glandulares que forman una depresión en la superficie foliar . A. hispidum, hierba erecta, hoja ovada o deltoide ovada, base cuneiforme, sésil; fruto aquenio cuneiforme comprimido, cubierto de espinas ganchudas, de las cuales dos sobresalen en forma divergente a manera de cuernos; parénquima en empalizada con una hilera de células. Palabras clave: morfoanatomía, Acanthospermum, planta medicinal.

Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

No Cerrado brasileiro (savana neotropical), o desenvolvimento de sistemas subterrâneos que produzem gemas, como estruturas adaptativas contra o fogo e períodos de seca, pode compreender um importante suprimento de gemas para esse ecossistema, como já demonstrado nos campos brasileiros e nas pradarias norte-americanas. Espécies de Asteraceae tanto do estrato lenhoso, quanto do herbáceo têm órgãos que acumulam carboidratos, reforçando a estratégia adaptativa dessas plantas a diferentes condições ambientais. Este estudo tem o objetivo de analisar a morfo-anatomia de sistemas subterrâneos de seis espécies de Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner e Vernonia megapotamica Spreng.), para descrever essas estruturas e verificar a ocorrência e origem de gemas caulinares, e analisar a presença de substâncias de reserva. Indivíduos amostrados em áreas de Cerrado no Estado de São Paulo apresentaram órgãos subterrâneos espessados produtores de gemas, com raízes adventícias ou laterais e presença de frutanos. Em todas as espécies estudadas foi constatada a presença de xilopódio, com exceção de Trixis nobilis, a qual apresentou caule tuberoso. A presença de frutanos como reserva e a capacidade de estruturas na formação de gemas indicam o potencial de espécies herbáceas de Asteraceae em formar um banco de gemas viável para regeneração da vegetação no Cerrado brasileiro.

Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado.

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

Identificação de espécies da família Asteraceae, revisão sobre usos e triagem fitoquímica do gênero Eremanthus da Reserva Boqueirão, Ingaí-MG / Asteraceae species identification, use revision and phytochemical screening of Eremanthus genus in Boqueirão Ecological Reserve, Ingaí - Minas Gerais State, Brazil

Com o objetivo de identificar espécies da família Asteraceae, revisar seus usos e realizar triagem fitoquímica preliminar do gênero Eremanthus procederam-se coletas botânicas semanais de espécimes na Reserva Boqueirão, localizada em Ingaí, Minas Gerais. As amostras foram herborizadas e identificadas utilizando-se bibliografia especializada e comparação com espécimes disponíveis no Herbário ESAL, da Universidade Federal de Lavras. A revisão dos usos foi feita através de consulta a obras clássicas e artigos científicos contendo relatos sobre levantamentos etnobotânicos realizados na área de estudo. Para triagem fitoquímica empregaram-se reagentes específicos para cada grupo de metabólito. Foram levantadas 102 espécies da família Asteraceae, sendo 32 delas úteis para o homem. A triagem fitoquímica dos extratos hidroalcoólicos indicaram a presença de açúcares redutores, carboidratos, aminoácidos, taninos, flavonóides, glicosídeos cardiotônicos, carotenóides, esteróides e triterpenóides, depsídeos e depsidonas, derivados de cumarina, saponinas espumídicas, alcalóides, purinas, polissacarídeos e antraquinonas. Não foram detectados ácidos orgânicos, catequinas, lactonas sesquiterpênicas e azulenos.

To identify Asteraceae species, review the utilization and perform a preliminary phytochemical screening of some species of Eremanthus genus, plants were weekly collected in Boqueirão Ecological Reserve, located in Ingaí, Minas Gerais State, Brazil. The samples were herborized and identified by using a specialized bibliography and comparison with the species available in the Herbarium ESAL of the Federal University of Lavras. The utilization review was carried out by means of bibliographical research and ethnobotanical surveys in the sampling area. Specific reagents for each group of compounds were used for phytochemical screening. From the 102 Asteraceae species investigated, 32 were reported to be of use to humans. The phytochemical screening of the hydroalcoholic extracts indicated the presence of reducing sugars, carbohydrates, amino acids, tannins, flavonoids, glycosides cardiotonics, carotenoids, steroids and triterpenoids, depsides and depsidones, coumarin derivatives, soapy saponins, alkaloids, purines, polysaccharides and anthraquinones. On the other hand, organic acids, catechins, sesquiterpene lactones and azulenes were not detected.

Inferring possible population divergence in Espeletia pycnophylla (Asteraceae) through morphometric and paleogeographic approaches

The phenotypic structure within and between plant populations is generally influenced by their distribution patterns in space and time; therefore, the study of their divergence is a central issue for the understanding of their microevolutive processes. We boarded the hypothesis that three populations of Espeletia pycnophylla show phenotypic divergence as one of the possible implications of their geographic isolation in the Southern Colombian Andes. We used the Elliptic Fourier Descriptors (leaf shape) and traditional leaf morphometry (leaf size) of 347 leaves to measure inter and intra-population variation and a comparison between a paleogeographic reconstruction with an actual estimate of the distribution areas of E. pycnophylla in order to identify their main changes during the last 14 000 years. The three populations showed significant differences in leaf morphometry and a positive correlation between the matrices of morphometric and geographic dissimilarities, indicating that the inter-population divergence increases between further populations, so that the morphometric structure reflects their spatial distribution. The geographical and paleogeographical estimates evidenced a conspicuous process of reduction and fragmentation of the distribution area of E. pycnophylla since the Late-Glacial until the Holocene. We suggest that these results support possible scenarios of vicariance events, which allow us to approach the divergence of these populations in terms of their historic biogeographic relations. However, genetic analyses are still needed to support these results. Rev. Biol. Trop. 58 (4): 1261-1270. Epub 2010 December 01.

La estructuración fenotípica entre y dentro de poblaciones vegetales responde generalmente a sus patrones de distribución espacio-temporales, por lo tanto, el estudio de su divergencia es un tema central dentro de sus procesos microevolutivos. En esta investigación abordamos la hipótesis que tres poblaciones de Espeletia pycnophylla presentan divergencia fenotípica como uno de los posibles efectos de su aislamiento geográfico en los Paramos del suroeste de Colombia. Utilizamos los Descriptores Elípticos de Fourier (forma foliar) de 117 hojas y algunas medidas morfológicas tradicionales (tamaño foliar) como indicadores de la variación intra e inter-poblacional, además de una comparación entre una reconstrucción paleogeográfica con una estimación del área de distribución actual de la especie para identificar sus principales cambios durante los últimos 14 000 años. Todas las poblaciones mostraron diferencias significativas y además, existió una correlación positiva entre las matrices de disimilitud morfométrica y geográfica, indicando que la divergencia incrementa entre poblaciones lejanas. Paralelamente, las estimaciones geográficas y paleogeográficas evidenciaron un proceso de reducción y fragmentación del área de distribución de E. pycnophylla desde el Tardiglacial hasta el Holoceno. Sugerimos que ambos resultados apoyan escenarios de posibles series de eventos de vicarianza para las poblaciones estudiadas y nos permiten entender su divergencia en términos de sus relaciones biogeográficas históricas.

Eocene Patagonia fossils of the daisy family.

Fossil capitula and pollen grains of Asteraceae from the Eocene of Patagonia, southern Argentina, exhibit morphological features recognized today in taxa, such as Mutisioideae and Carduoideae, that are phylogenetically close to the root of the asteracean tree. This fossil supports the hypothesis of a South American origin of Asteraceae and an Eocene age of divergence and suggests that an ancestral stock of Asteraceae may have formed part of a geoflora developed in southern Gondwana before the establishment of effective dispersal barriers within this landmass.