Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 112-121). Also available on the World Wide Web.

Craspedia (Compositae: Gnaphalieae) is a genus of 23 species found only in Australia and New Zealand. New Zealand species of Craspedia have confusing and continuous character variation, with boundaries between species often indistinct and relationships difficult to elucidate. Taxonomic treatments in the genus so far have been regionally based, with the result that species between New Zealand and Australia have not been adequately compared. Phylogenetic analyses of ITS, ETS and psbA-trnH non-coding spacers show that New Zealand Craspedia is a monophyletic group nested within Australian Craspedia. This is consistent with a jump-dispersal event from Australia to New Zealand across the Tasman Sea. The New Zealand lineage is identified as sister to one of two Australian lineages, which consists of mainly subalpine and alpine species found on the main divide of south eastern Australia and in Tasmania. An estimate of when New Zealand Craspedia diverged, using ITS substitution rates from other mainland/island disjunctions in Compositae, gave an approximate date of between 650,000 and 325,000 years ago. This is consistent with the New Zealand fossil pollen record, and with other molecular studies, in suggesting that the Pleistocene, a period of mountain building and climate change, has been an important factor in the evolution of the New Zealand herbaceous flora. The two Australian lineages have not previously been recognised based on morphology and it is suggested they represent two independent species radiations into the Australian alpine zone. Although the New Zealand clade is only partly resolved, the phylogenetic analyses of ITS and ETS indicate that some relationships are incongruent with those previously suggested by morphology and current species boundaries.

The dichloromethane extracts (1 mg/ml) of Artemisia pacifica Nutt and Guardiola platyphylla Gray (fam. Asteraceae) separately demonstrated in vitro growth inhibition of Staphylococcus aureus (UA 9-29), Bacillus subtilis (UA 2-27), Klebsiella pneumoniae (UA 3-9) and Candida albicans (UA 97). Each of these extracts were subjected to bioassay-directed solvent extraction and partition in order to obtain concentrated active fractions. Subsequently, the active compounds were isolated and identified from these fractions. Artemisia pacifica Nutt. The active compound was the major component isolated from A. pacifica. By comparing the physical and chemical data with previously reported data, this compound was identified as dehydrofalcarindiol. Dehydrofalcarindiol demonstrated growth inhibition against S. aureus (50 μg/ml), B. subtilis (25 μg/ml), K. pneumoniae (100 μg/ml) and C. albicans (25 μg/ml). Its diacetyl derivative was devoid of activity at 100 μg/ml. Guardiola platyphylla Gray. The active fraction obtained from G. platyphylla contained unstable compounds that decomposed in the presence of air. Size exclusion chromatography (Sephadex LH-20) was used to fractionate the active fraction. Two new sesquiterpenes, the o-catechol derivatives (1S,4S) and (1S,4R)-7,8-dihydroxy-11,12-dehydrocalamenene, were eluted from the column as a mixture. The mixture of their diacetyl derivatives was oxidized with CrO₃ in AcOH. The major oxidation product was identified as (1S)-7,8-diacetyl-4-oxodeisopropylcalamenene, thereby verifying the sole difference to be the configuration at C-4. This sesquiterpene mixture completely inhibited the growth of S. aureus (100 μg/ml), B. subtilis (50 μg/ml), K. pneumoniae (100 μg/ml) and C. albicans (100 μg/ml). After removal of the sesquiterpenes from the active fraction, the remaining compounds displayed the same level of activity. Another six compounds were also isolated from this mixture as acetylated derivatives due to their instability. Their dimeric structures were identified by 2D-NMR techniques (COSY, HETCOR and NOESY). These dimers may be artifacts since they were formed from their o-quinone monomers when kept at room temperature for a week or when heated at 60°C for 4 hours.

o presente trabalho estuda a evolução química em Asteraceae com base em dados da literatura a respeito de vários grupos de metabólitos secundários (poliacetilenos, lactonas sesquiterpênicas, diterpenos, triterpenos, flavonóides e ácidos ramificados). Foram usadas três diferentes metodologias quimiotaxonômicas. A primeira, baseada no cálculo de parâmetros evolutivos em relação à oxidação e em relação à especialização de esqueleto de substâncias, resultou numa abordagem fenética das relações entre as tribos de onde foram isoladas as substâncias. A segunda, baseada em análise de grupos, resultou numa abordagem filética da evolução de Asteraceae. A terceira, baseada em estudos computacionais e em banco de dados, tenta comprovar a validade dos parâmetros utilizados nas duas etapas iniciais realizando estudos de previsão sobre a posição taxônomica e sobre a composição química de gêneros da família. Os resultados obtidos usando parâmetros evolutivos calculados para as tribos ou usando taxonomia numérica evidenciaram o caráter bifilético da famíliao Foi sugerida uma sequência evolutiva desde o precursor até os grupos mais avançados. Os resultados fornecem também uma comprovação experimental de um dos princípios da sistemática micromolecular. O surgimento de novas linhagens botânicas é acompanhado pe1o explosivo aumento do estado de oxidação de um importante grupo biogenético. O desenvolvimento posterior da linhagem é acompanhado pela gradativa diminuição do grau de oxidação. O princípio permite acompanhar a evolução química da família. Algumas relações entre especiação e quimismo ficaram evidenciadas. / This thesis describes the chemical evolution in Asteraceae based on bibliographic data about groups of secondary metabolites (polyacetylenes, sesquiterpene lactones, diterpenes tritepenes, flavonoids and chain ramified acids). Were used three chemotaxonomic methodologies. The first based on evolutive parameters calculation (oxidation and specialization indexes of isolated substances) which gave a phenetie approaching concerning of the relationships among tribes containing the considered substances. The second, based on cluster analisys gave a phyletic approaching concerning of Asteraceae evolution. The third, based on computational studies and on data bases, comproves the validity of the parameters obtained by the two previous approachings, making prevision studies about the taxonomic position and about the chemistry composition of taxa. The evidence for the biphyletic constituion was showed by using evolutive parameters calculated for the tribes or numerical taxonomy. Were suggested evolutive steps from the precursor to the more advanced groups in the family. The results obtained provide experimental corroboration of a Micromolecular sistematics postulate: \"The development of novel botanic lineage is accompained by vigorous increase in oxidation state of allelochemics. The posterior development of the lineage is accompained by a diminution in the oxidation state. This postulate permits to study the chemical evolution of the family. Were evidenced, using the known evolutive sequences, others relationships between speciation and chemistry composition of taxa.

A variação sazonal na produção de compostos secundários em Tithonia diversifolia (Hemsl) Gray foi investigada desde a primavera de 2002 até o inverno de 2003. Coletas bimensais foram realizadas com posterior extração e fracionamento do material vegetal (folhas e flores). As amostras foram monitoradas por CCD e analisadas quanto a atividade antimicrobiana contra Staphylococcus aureus, Escherichia coli, Salmonella choterasuis e Pseudomonas aeruginosa, pelo método de microplaca. Os perfis cromatográficos foral distintos para as diferentes épocas do ano, sendo evidenciada a presença de um grupo de substâncias em maior quantidade no mês de Abril de 2003 (outono), período de pré-florada desta espécie. Os extratos foram ativos para apenas dois microrganismos dentre os quatro testados. Algumas frações apresentaram CIM (concentração inibitória mínima) significativa (<1mg/mL). / The seasonal variation upon production of active compounds in Tithonia diversifolia (Hemsl) Gray was investigated from spring of 2002 until winter of 2003. Leaf samples were collected every three months for posterior extraction and analysis . The samples were monitored by Thin Layer Chromatography (TLC) and analyzed for anti-microbial activities on Staphylococcus aureus, Escherichia coli, Salmonella choterasuis and Pseudomonas aeruginosa, using micro-plate method. The TLC results showed a clear accumulation of active compounds during April . The extracts were active for only two microorganisms of a total of four studied.

o presente trabalho estuda a evolução química em Asteraceae com base em dados da literatura a respeito de vários grupos de metabólitos secundários (poliacetilenos, lactonas sesquiterpênicas, diterpenos, triterpenos, flavonóides e ácidos ramificados). Foram usadas três diferentes metodologias quimiotaxonômicas. A primeira, baseada no cálculo de parâmetros evolutivos em relação à oxidação e em relação à especialização de esqueleto de substâncias, resultou numa abordagem fenética das relações entre as tribos de onde foram isoladas as substâncias. A segunda, baseada em análise de grupos, resultou numa abordagem filética da evolução de Asteraceae. A terceira, baseada em estudos computacionais e em banco de dados, tenta comprovar a validade dos parâmetros utilizados nas duas etapas iniciais realizando estudos de previsão sobre a posição taxônomica e sobre a composição química de gêneros da família. Os resultados obtidos usando parâmetros evolutivos calculados para as tribos ou usando taxonomia numérica evidenciaram o caráter bifilético da famíliao Foi sugerida uma sequência evolutiva desde o precursor até os grupos mais avançados. Os resultados fornecem também uma comprovação experimental de um dos princípios da sistemática micromolecular. O surgimento de novas linhagens botânicas é acompanhado pe1o explosivo aumento do estado de oxidação de um importante grupo biogenético. O desenvolvimento posterior da linhagem é acompanhado pela gradativa diminuição do grau de oxidação. O princípio permite acompanhar a evolução química da família. Algumas relações entre especiação e quimismo ficaram evidenciadas. / This thesis describes the chemical evolution in Asteraceae based on bibliographic data about groups of secondary metabolites (polyacetylenes, sesquiterpene lactones, diterpenes tritepenes, flavonoids and chain ramified acids). Were used three chemotaxonomic methodologies. The first based on evolutive parameters calculation (oxidation and specialization indexes of isolated substances) which gave a phenetie approaching concerning of the relationships among tribes containing the considered substances. The second, based on cluster analisys gave a phyletic approaching concerning of Asteraceae evolution. The third, based on computational studies and on data bases, comproves the validity of the parameters obtained by the two previous approachings, making prevision studies about the taxonomic position and about the chemistry composition of taxa. The evidence for the biphyletic constituion was showed by using evolutive parameters calculated for the tribes or numerical taxonomy. Were suggested evolutive steps from the precursor to the more advanced groups in the family. The results obtained provide experimental corroboration of a Micromolecular sistematics postulate: \"The development of novel botanic lineage is accompained by vigorous increase in oxidation state of allelochemics. The posterior development of the lineage is accompained by a diminution in the oxidation state. This postulate permits to study the chemical evolution of the family. Were evidenced, using the known evolutive sequences, others relationships between speciation and chemistry composition of taxa.

A presente tese tenta demonstrar a validade do uso de lactonas sesquiterpênicas como marcadores sistemáticos em angiospermas, principalmente dentro da família Asteraceae, onde se encontram quase todas as substâncias isoladas até o momento. O trabalho teve como etapa inicial o levantamento de dados sobre ocorrência de lactonas sesquiterpênicas em plantas, e a sistematização desdes dados de acordo com a classificação vegetal das espécies portadoras destas substâncias. Na tentativa de estabelecer os prováveis caminhos evolutivos destas micromoléculas, e usá-las como marcadores sistemáticos, utilizam-se dois parâmetros químicos designados O e E. O primeiro consiste em um índice de oxidação médio por átomo de carbono das substâncias. O segundo consiste em um grau de especialização dos esqueletos, dado ou pelos seus números de ordem nas colunas do esquema biogenético, ou pelo seu número médio de transformações (ligamento ou desligamento de ligações carbono-carbono) sofridos por cada átomo de carbono do esqueleto em comparação com um precursor. As médias dos valores de O e E de lactonas sesquiterpênicas de um taxon produzem seus respectivos AEo e AEe , ou seja seus índices de avanço evolutivo em relação a oxidação e à especialização destas substâncias. Estes foram comparados (a nível de família) com índices de evolução morfológicasegundo Sporne (IS) obtendo bons resultados. Com base na metodologia indicada traçou-se para o grupo das lactonas sesquiterpênicas um caminho evolutivo provável que ajuda a entender as relações filéticas entre Apiaceae e Asteraceae. Dentro de Asteraceae, lactonas sesquiterpênicas mostram-se úteis para confirmar os trabalhos mais recentes da subdivisão da família em subfamílias e tribos. Dentro da tribo Heliantheae a análise de dados citogenéticos, aliados aos valores de AEo e AEe , mostra claramente tendências paralelas dos números de cromossomos das subtribos, comparados com a diversificação estrutural e o nível de oxidação de suas substâncias. Finalmente o valor dos índices AEo e AEe em classificação vegetal foi posto a prova tentando classificar, dentro das tribos de Asteraceae, espécies recentemente estudadas, obtendo-se excelentes resultados. / The present thesis attempts to demonstrate the validity of the use of sesquiterpene lactones as systematic markers in angiosperms, chiefly in the family Asteraceae where nearly all presently known compounds are located. Initially all published data on the occurrence of sesquiterpene lactones in plants are listed. followed by the systematization of the data with respect to the classification of the sesquiterpene lactone containing species. In the attempt to establish the probable evolutionary pathways of these micromolecules and to use them as systematic markers, two chemical parameters. designated O and S, were used. The former consists in a mean oxidation index per carbon atom of the compounds. The latter consists in a specialization index for skeletons, given by the symbols which define their position on the columns of the biogenetic scheme, or by the mean number of transformations (formation or breakage of carbon-carbon bonds) suffered by each carbon atom of a skeleton in comparason with a precursor. The means of the O and E values of sesquiterpene lactones of a taxon give the respective EAo and EAe values, i. e. their evolutionary advancement in relation to the oxidation state and the skeletal specialization of these compounds. The EA values were compared (at the family leveI) with Sporne indices (SI) based on morphological criteria. Based on the indicated methodology a probable pathway for the biogenetic group of sesquiterpene lactones was developed. This aids in the understanding of phyletic relations between Apiaceae and Asteraceae. Within the Asteraceae sesquiterpene lactone data are consistent with recent subdivisions of the family in subfamilies and tribes. Within the tribe Heliantheae the analysis of cytagenetic data, compared with EAo and EAe values, shows clearly parallel trends in the number of the chromosomes of the subtribes, as compared with the oxidation state and the skeletal specialization of their sesquiterpene lactones. Finally the value of the EAo and EAe indices in plant classification was evaluated achieving the placement, within the Asteraceae tribes, of recently studied species with satisfactory results.

Bioactivity-guided isolation of SFE oil led to the identification of another sesquiterpene lactone, 6-O-angeloylprenolin, containing the bioactive alpha, beta-unsaturated cyclopentenone. MTT results showed that CNE cells were more susceptible to 6-O-angeloylenolin than the normal Hs68 cells. Besides, the inhibitory effect of 6-O -angeloylenolin on the CNE cells was slightly stronger than that of cisplatin, the positive control, albeit statistical insignificance. / Both volatile oils prepared by supercritical fluid extraction (SFE) and steam distillation (SD) were evaluated for their anti-NPC potential. Results showed that SFE oil was much stronger than that of SD oil. SFE oil significantly inhibited the growth of CNE cells by dysfunctioning the mitochondria and activating caspases. Gas chromatography-mass spectrometry analysis revealed that the responsible principals in the SFE oil were likely homologues of sesquiterpene lactones. / Centipeda minima (L.) A. Br. (Compositae), a Chinese medicinal herb, is used to treat nasopharyngeal carcinoma (NPC) in the Chinese folk. However, there is a paucity of information on its anticancer activities. In particular, both of its anti-NPC potential and the potent constituents remain elusive. / In this study, the n-hexane fraction of C. minima showed broad spectrum of inhibitory effects on five human cancer cell lines, including the breast carcinoma MCF7 cells, the prostate carcinoma PC-3 cells, the hepatocellular carcinoma Hep G2 cells, the nasopharyngeal cancer CNE cells and the acute promyelocytic leukemia HL-60 cells, with IC 50 values ranging from 6.1 to 47.3 mug/mL. Bioactivity-guided separation of the n-hexane fraction using the CNE cells as the cellular system led to the isolation of a sesquiterpene lactone, 2beta-(isobutyryloxy)florilenalin (IF), which contained the bioactive alpha-methylene-gamma-lactone ring. IF significantly induced CNE cell death with an IC50 value of 3.1 mug/mL. Despite this potency, its effect on the normal Hs68 cells was much weaker, with an IC50 value larger than 50 mug/mL. Its inhibitory effect on the CNE cells ascribed to apoptotic induction as evidenced by the cumulation of sub-G1 cell population, DNA fragmentation and nuclear condensation, caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage. Mechanistic study showed that both extrinsic and intrinsic apoptotic pathways were activated. In the extrinsic pathway, IF activated caspase-8, which further induced the activation of caspase-3 and caspase-7. In the intrinsic pathway, IF regulated the expressions of Bcl-2 family proteins, followed by depletion of mitochondrial membrane potential (Delta&PSgr;m), the release of cytochrome c to cytosol, the activation of caspase-9 and other downstream caspases, and finally the induction of apoptosis. / Mechanistic investigation showed that 6-O-angeloylenolin caused cell cycle arrest at S and G2/M phases and induced apoptosis in CNE cells. For the cell cycle arrest, a sharp decrease was found in the expressions of cyclin D1, cyclin D3, cdc25c, and p-cdc25c, with concomitant decrease in CDK4, cyclin A, cyclin E, p-Rb(Ser780), p21Waf1/Cip1, cdc2 and p-cdc2. For the induction of apoptosis, externalization of phosphatidylserine and depletion of Delta&PSgr;m prior to the detection of sub-G1 peak were found. Other apoptotic features including the presence of apoptotic bodies, the activation of caspase-3 activity and the cleavage of PARP were observed. Activation of caspase-8 and caspase-10 was detected. Besides, 6-O -angeloylenolin induced the release of cytochrome c and AIF to cytosol. The former formed apoptosome with caspase-9, further activated the downstream caspase-3 and caspase-7 and cleaved PARP, while the latter was translocated into the nucleus and caused large-scale DNA fragmentation. Failure of the pan-caspase inhibitor, z-VAD-fmk, to interrupt the apoptotic induction by 6-O-angeloylenolin suggested that caspase-independent pathway was involved. 6-O-Angeloylenolin was able to activate Akt, ERK and JNK pathways. But only with the addition of JNK inhibitor (SP600125), significant suppression of the 6-O-angeloylenolin-induced apoptosis was observed, suggesting the involvement of the JNK pathway in the apoptotic pathway. Taken together, this study provided a better mechanistic insight into the potential application of 6-O-angeloylenolin as a candidate for NPC treatment. / Overall, this study revealed that two sesquiterpene lactones, including IF and 6-O-angeloylenolin were found to be responsible for the potent anti-NPC effect of C. minima. This study reiterates the notion that Chinese medicinal herbs traditionally applied to cancer treatment may be good sources of anticancer drug discovery, and sesquiterpene lactone may be a group of noteworthy lead compounds displaying anti-NPC potential. / Su, Miaoxian. / Adviser: Hau Yin Chung. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 100-113). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-09-22T18:40:11Z No. of bitstreams: 2 Moreira, Giselle Lopes-2013-dissertação.pdf: 4190690 bytes, checksum: 100f75f7b9afd4680f4462b266f235b1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-09-22T18:58:00Z (GMT) No. of bitstreams: 2 Moreira, Giselle Lopes-2013-dissertação.pdf: 4190690 bytes, checksum: 100f75f7b9afd4680f4462b266f235b1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-22T18:58:00Z (GMT). No. of bitstreams: 2 Moreira, Giselle Lopes-2013-dissertação.pdf: 4190690 bytes, checksum: 100f75f7b9afd4680f4462b266f235b1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The tribe Vernonieae Cass. (Asteraceae) Serra Dourada, Goiás, Brazil. The tribe Vernonieae belongs to Cichorioideae, has 21 subtribes, 119 genera and approximately 1000 species, having a pantropical distribution. For Brazil are cited 55 genera and 437 species. In Goiás state are recorded 19 genera and 129 species. The aim of this study is to present the taxonomic treatment of the species of the tribe Vernonieae from Serra Dourada, Goiás. The collections were made between September 2011 and December 2012, and all material was depositated in UFG herbarium. The species were described based on all material examined (own collections and collections from the herbaria RB, UB and UFG). It is presented an identification key for the taxa found in the study area, as well as descriptions, followed by taxonomical comments, such as morphological variability and affinity between the taxa, comments on geographic distribution and phenology, as well as illustrations. Were found 30 species grouped in 13 genera and seven subtribes. The most representative genus was Lessingianthus H. Rob. (11 spp.), followed by Chresta Vell. ex DC. and H. Vernonanthura Rob. (3 spp. each), all together representing about 57% of the total, other four genera (Chrysolaena H. Rob., Elephantopus L., Eremanthus Less. and Lepidaploa (Cass.) Cass.) are represented by two species each, and six other genera (Centratherum Cass., Echinocoryne H. Rob., Lychnophora Mart., Piptocarpha R. Br, Stenocephalum Sch.Bip. and Strophopappus DC.) with one species each. From the total species number, 76% are represented by shrub or subshrub layer, 17% herbaceous and 7% woody. Some species found in the study area have restricted geographical distribution as Chresta curumbensis (Philipson) H. Rob. (Goiás and Mato Grosso), C. speciosa Gardner (Goiás and Tocantins), Lessingianthus hoveaefolius (Gardner) H. Rob. (Goiás and Minas Gerais) and L. soderstroemii (H. Rob.) H. Rob. (Distrito Federal and Goiás). Lessingianthus rigescens (Malme) Dematt. is a new record for Goiás state, this species was initially reporterd for Mato Grosso. The study it is the first taxonomic treatment of tribe Vernonieae to some locality in the Goiás state. / A tribo Vernonieae Cass. (Asteraceae) na Serra Dourada, Goiás, Brasil. A tribo Vernonieae pertence a família Asteraceae, subfamília Cichorioideae, possui 21 subtribos, 119 gêneros e aproximadamente 1000 espécies, possuindo uma distribuição pantropical. Para o Brasil são citados 55 gêneros e 437 espécies. No estado de Goiás são registrados 19 gêneros e 129 espécies. O objetivo do presente trabalho é apresentar o tratamento taxonômico das espécies pertencentes à tribo Vernonieae ocorrentes na Serra Dourada, Goiás. As coletas foram realizadas no período de setembro de 2011 a dezembro de 2012 e todo material coletado encontra-se depositado no herbário UFG. As espécies foram descritas com base em todo material examinado (coleções próprias e coleções dos herbários RB, UB e UFG). Para tal é apresentada uma chave de identificação para os táxons encontrados na área de estudo, bem como descrições, seguidas de comentários taxonômicos, tais como variabilidade morfológica e afinidade entre os táxons, comentários sobre distribuição geográfica e fenologia, bem como ilustrações. Foram encontradas na área de estudo 30 espécies agrupadas em 13 gêneros e sete subtribos. Os gêneros mais representativos foram Lessingianthus H. Rob. (11 spp.), Chresta Vell. ex DC. e Vernonanthura H. Rob. (3 spp. cada), representando cerca de 57% do total, os quatro gêneros (Chrysolaena H. Rob., Elephantopus L., Eremanthus Less. e Lepidaploa (Cass.) Cass.) estão representados por duas espécies cada e outros seis gêneros (Centratherum Cass., Echinocoryne H. Rob., Lychnophora Mart., Piptocarpha R. Br., Stenocephalum Sch.Bip. e Strophopappus DC.) com uma espécie cada. Do total de espécies, 76% são representadas pelo estrato arbustivo ou subarbustivo, 17% herbáceo e 7% arbóreo. Algumas espécies encontradas na área de estudo possuem distribuição restrita como Chresta curumbensis (Philipson) H. Rob. (Goiás e Mato Grosso), C. speciosa Gardner (Goiás e Tocantins), Lessingianthus hoveaefolius (Gardner) H. Rob. (Goiás e Minas Gerais) e L. soderstroemii (H. Rob.) H. Rob. (Distrito Federal e Goiás). Lessingianthus rigescens (Malme) Dematt. é uma nova ocorrência para o estado de Goiás, citada anteriormente somente para o Mato Grosso. O presente trata-se de um trabalho inédito, sendo o primeiro a abordar o tratamento taxonômico da tribo Vernonieae para alguma localidade do estado de Goiás.

The present paper present a taxonomic study of the Brazilian species of the genus Aspilia Thou. (Compositae-Heliantheae). AlI taxa involved, and their geografical distribution, are described, discussed, and illustrated. The material examined is listed, and a dichotomus key for the identification of the Brazilian species of Aspilia, is presented. About 1200 exsiccatae, from 22 Brazilian and 16 foreign herbaria, were studied, 61 species are recognized, 19 of which are new to science. The genus is maintained in the tribe Heliantheae. The genus Aspilia can be distinguished from other genera of Heliantheae in having ligulate and neuter radial flowers with two or three conspicuous veins, and central achenium slightly compressed, with a scar at its base, from the carpophore. The genus, with about 155 recognise species, occurs in Afr ica, Madagascar, and Tropical. America from Mexico to Argentina. In Brazil, most species are found in "ambientes rupestres", in "cerrados", in gallery forests, and in "restinga", mainly in the states of Minas Gerais, Goiás, Bahia, Mato Grosso, and Mato Grosso do Sul / Expõe-se neste trabalho um estudo taxonômico das espécies brasileiras do gênero Aspilia Th. (Compositae-Heliantheae). Os taxa, com suas respectivas distribuições geográficas, são descritos, discutidos e ilustrados.Elaborou-se relação de material examinado e uma chave dicotômica com a finalidade de identificar as espécies brasileiras, muitas das quais apresentam grande afinidade entre si. Com base no estudo de cerca de 1.200 exsicatas, provenientes de 22 herbários nacionais e 16 herbários do exterior, 61 espécies são reconhecidas, das quais 19 são novas. O gênero é mantido na tribo Heliantheae s.l., subtribo Ecliptinae. O gênero Aspilia, além de outras características de menor expressão, pode ser distinguido de outros da tribo por apresentar flores do raio liguladas e neutras, com duas a três nervuras conspícuas e aquênio do disco, levemente comprimido, com cicatriz na base. O gênero com cerca de 155 nomes é encontrado na África, Madagascar e no continenete americano desde o México até à Argentina. - No Brasil, a maioria das espécies se encontra em ambiente rupestre, cerrado, mata de galeria e restinga, principalmente nos Estados de Minas Gerais, Goiás, Bahia, Mato Grosso e Mato Grosso do Sul