This study extends an earlier M.Sc. research project on the narrow-leaved species of the genus Asclepias L. (30 species) to cover the entire subtribe Asclepiadinae sensu K. Schum. in southern Africa- (182 species in 23 genera). Two genera (Eustegia R. Br. and Pentarrhinum E. Mey.) are revised and then removed from this tribe. The remaining 177 species and 21 genera form the focus of this thesis, whose principal objectives are to reevaluate the taxonomic and evolutionary significance of various macro, micro and chemical characters and then use them to produce a classification that, more closely, reflects the overall similarity and phylogeny of the taxa involved. Species and genera are recircumscribed based on the wealth of data that has come to light since the subtribe was last revised by N.E. Brown (1907-1908) some 90 years ago. This process was supplemented by extensive field work, observations on pollination and reproductive biology, ecology, biogeography, conservation and ethnobotany. The majority of this thesis consists of a compilation of 17 papers, 12 of these published and most, but not all, of the remainder in preparation for press. Two of these papers form the bulk of the taxonomy. The first deals with what was the genus Asclepias in southern Africa. The genus is now believed to be confined to the Americas. The • Botswana, Lesotho, Namibia, South Africa and Swaziland. southern African species have diverse origins and are partitioned into 7 genera, one of them (Gomphocarpus R. Br.) resurrected, two of them (Aidomene Stopp and Aspidonepsis Nicholas & Goyder) expanded and four of them (Paulforstera, Sigridia, Bruynsia and Pachyacris) described as new. Gomphocarpus is divided into two subgenera and Aidomene into four subgenera. Three new species are also described. The second paper investigates the bulk of most of the remaining genera. Kanahia R. Br., Cordylogyne E. Mey. and Fanninia Harv. remain as is. Xysmalobium R. Br., previously a genus of 19 species in southern Africa, is reduced to three species in two subgenera. Trichocodon is segregated off from Pachycarpus E. Mey. as a new genus. While two species, previously placed in Xysmalobium, are added to Pachycarpus, but placed in the new subgenus Parapodiopsis. Parapodium E. Mey. is reduced from three to two species and Periglossum Decne. is reduced from five to three species, one of them newly described. Woodia Schltr. and Stenostelma Schltr. are both considerably expanded, mainly with species previously housed in Xysmalobium), and the former divided into two subgenera. The third paper briefly looks at the Schizoglossum E. Mey., Miraglossum Kupicha and Aspidoglossum E. Mey. Some changes are suggested but, as further work is needed, none are formalised. As a corollary to the taxonomy, secondary metabolite profiles of 38 species and 17 genera were done using Thin layer Chromatography. The results sometimes confirmed morphological patterns and sometimes were at odds with them. A trend from simple profiles to more complex profiles seems to echo the suspected phylogeny of the genera within this sub tribe. Some species and genera have greater chemical diversity than others and secondary metabolites are shown to vary considerably in different parts of a single plant. As a supplement to the above work or because they are cited elsewhere in the dissertation, published papers dealing with floral structure, the asclepiadaceous work of Rudolf Schlechter, as well as miscellaneous works in the tribe Stapelieae, are also given. / Thesis (Ph.D.)-University of Durban-Westville, 1999.

Diss. (sammanfattning) Uppsala : Univ., 2007. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 6 uppsatser.

Orientador: Andréia Alves Rezende / Coorientador: Marco Antônio Assis / Banca: Elza Guimarães / Banca: Veridiana de Lara Weiser / Resumo: O presente trabalho visou estudar a composição das espécies de Bignoniaceae no noroeste paulista a fim de auxiliar no conhecimento da flora do interior do estado, onde foram amostrados 18 remanescentes de vegetação nativa. Os fragmentos do noroeste paulista são recobertos por floresta estacional semidecidual, cerradão e quatro classificados como mata de transição (entre floresta estacional semidecidual e cerradão), ambos ameaçados pelo histórico de degradação e exploração predatória, em função particularmente das atividades agropastoris. Os remanescentes florestais na região estão extremamente fragmentados, tal impacto coloca o noroeste paulista como uma das regiões mais desmatada e fragmentada do estado e com a menor concentração de unidades de conservação. A família Bignoniaceae apresenta 827 espécies distribuídas em 82 gêneros com espécies predominantemente neotropicais. No presente estudo foram identificadas 46 espécies pertencentes a 19 gêneros, o gênero Fridericia é o mais representativo com 11 espécies. Verificou-se também, a partir de técnicas de ordenação que os fragmentos não apresentaram diferença na composição de espécies independente do tamanho, mas quando separados pela formação, os fragmentos de floresta estacional semidecidual se agruparam. Considerando a riqueza em espécies, a hipótese de que as métricas da paisagem influenciam na riqueza foi confirmada, pois quanto maior a área do fragmento, maior foi o número de espécies de Bignoniaceae. Os resultados foram organizados em dois capítulos: o primeiro aborda a composição da família na região, apresenta uma chave de identificação das espécies baseada principalmente em características vegetativas, comentários taxonômicos e geográficos, além de figuras que ilustram as estruturas vegetativas e ou... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work aimed to study the species composition of Bignoniaceae in northwestern São Paulo state in order to do inventory of the flora of the state, where 18 remnants of native vegetation were sampled. The fragments in northwestern São Paulo are covered by seasonal semideciduous forest, woodland savanna and transition forest, both threatened by the history of degradation and predatory exploitation, particularly in the light of agropastoral activities. The Forest remnants in the region are extremely fragmented, such an impact puts the northwestern São Paulo as one of the most deforested and fragmented regions of the state with the lowest concentration of conservation units. The family Bignoniaceae has about 827 species in 82 genera with predominantly neotropical species. The present study identified 46 species belonging to 19 genera, the genus Fridericia is the most representative with 11 species. It was also found from ordering techniques that the fragments did not differ in species composition regardless of size, but when separated by the vegetation, the fragments of seasonal semideciduous forest were grouped. Considering the species richness, the hypothesis that landscape metrics influence the wealth has been confirmed, because the larger the area of the fragment, the greater number species of Bignoniaceae. The results were organized into two chapters: the first deals with the composition of the family in the area, provides an identification key for species based primarily on vegetative characteristics, taxonomic and geographic comments, and figures that illustrate the vegetative or reproductive structures and to... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:29:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-16Bitstream added on 2014-06-13T20:28:15Z : No. of bitstreams: 1 rodrigues_mc_me_botib.pdf: 2584319 bytes, checksum: 53bd0e46a7c71841f1eba2e0425e226c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho visou estudar a composição das espécies de Bignoniaceae no noroeste paulista a fim de auxiliar no conhecimento da flora do interior do estado, onde foram amostrados 18 remanescentes de vegetação nativa. Os fragmentos do noroeste paulista são recobertos por floresta estacional semidecidual, cerradão e quatro classificados como mata de transição (entre floresta estacional semidecidual e cerradão), ambos ameaçados pelo histórico de degradação e exploração predatória, em função particularmente das atividades agropastoris. Os remanescentes florestais na região estão extremamente fragmentados, tal impacto coloca o noroeste paulista como uma das regiões mais desmatada e fragmentada do estado e com a menor concentração de unidades de conservação. A família Bignoniaceae apresenta 827 espécies distribuídas em 82 gêneros com espécies predominantemente neotropicais. No presente estudo foram identificadas 46 espécies pertencentes a 19 gêneros, o gênero Fridericia é o mais representativo com 11 espécies. Verificou-se também, a partir de técnicas de ordenação que os fragmentos não apresentaram diferença na composição de espécies independente do tamanho, mas quando separados pela formação, os fragmentos de floresta estacional semidecidual se agruparam. Considerando a riqueza em espécies, a hipótese de que as métricas da paisagem influenciam na riqueza foi confirmada, pois quanto maior a área do fragmento, maior foi o número de espécies de Bignoniaceae. Os resultados foram organizados em dois capítulos: o primeiro aborda a composição da família na região, apresenta uma chave de identificação das espécies baseada principalmente em características vegetativas, comentários taxonômicos e geográficos, além de figuras que ilustram as estruturas vegetativas e ou... / The present work aimed to study the species composition of Bignoniaceae in northwestern São Paulo state in order to do inventory of the flora of the state, where 18 remnants of native vegetation were sampled. The fragments in northwestern São Paulo are covered by seasonal semideciduous forest, woodland savanna and transition forest, both threatened by the history of degradation and predatory exploitation, particularly in the light of agropastoral activities. The Forest remnants in the region are extremely fragmented, such an impact puts the northwestern São Paulo as one of the most deforested and fragmented regions of the state with the lowest concentration of conservation units. The family Bignoniaceae has about 827 species in 82 genera with predominantly neotropical species. The present study identified 46 species belonging to 19 genera, the genus Fridericia is the most representative with 11 species. It was also found from ordering techniques that the fragments did not differ in species composition regardless of size, but when separated by the vegetation, the fragments of seasonal semideciduous forest were grouped. Considering the species richness, the hypothesis that landscape metrics influence the wealth has been confirmed, because the larger the area of the fragment, the greater number species of Bignoniaceae. The results were organized into two chapters: the first deals with the composition of the family in the area, provides an identification key for species based primarily on vegetative characteristics, taxonomic and geographic comments, and figures that illustrate the vegetative or reproductive structures and to... (Complete abstract click electronic access below)

Ph.D. / This chemotaxonomic study of the leaf phenolic compounds in the genus Aloe is introduced by presenting a review of Aloe taxonomy, followed by a second review of all known leaf compounds. A chemotaxonomic study of virtually all species of Aloe has made it possible to define several chemical groups in the genus of 420 species. The chemical groups are either identified by a single marker compound or by a series of unique compounds. The following groups have been identified and the chemotaxonomic value of each group is discussed: • An aloin / aloinoside / microdontin group, comprising 36 species, mostly of tropical origin. This group includes species not previously associated with one another. • An 8-O-methyl-7-hydroxyaloin group. Here the co-occurrence of some leaf compounds suggests that 8-O-methyl-7-hydroxyaloin is not homologous in the 18 species where it has been detected. Evidence is presented illustrating that 8-O-methyl-7-hydroxyaloin is an 'hybrid compound' which forms when two chemically divergent species (aloin- and homonataloincontaining parents) are crossed. • An aloenin group, comprising 16 species which are believed to be a monophyletic group. • A microstigmin group, indicating a taxonomic alliance between series Purpurascentes and series Anguialoe, with A. broomii an intermediate between the two. • A 10-hydroxyaloin B group, represented by series Asperifoliae and related species, which appears to be a drought adapted Glade of tropical origin. • A homonataloside group, comprising 14 species, suggesting a biochemical link between the aloes of north Africa and southern Africa. • An aloeresin E and F group, indicating a taxonomic alignment between series Mitriformes and five anomalous species. • A plicataloside group, with its single marker compound indicating a taxonomic relationship between 20 mostly tropical east African species. • A flavone group. The large number of species with flavones (sections Leptoaloe Graminialoe, Lomatophyllum and series Macrifoliae) are suggested to be basal in the genus. • A flavanone group. A few anomalous species produce flavanones but it is unlikely that they form a monophyletic group. A concluding review of leaf exudate compounds (not mentioned above) is also presented which includes hypotheses on the chemotaxonomic value of chromones and anthrones in general. A chemical re-arrangement of species is presented in the form of a new 'chemical classification' for Aloe based on chemotypes. These chemical groups have lead to an improved understanding of natural relationships in a genus where no satisfactory infrageneric classification has hitherto been available.

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No description available.

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No description available.