Morphometrics was used to study variation in Schizeae pectinata as previous study showed that material originating from the summer rainfall area of South Africa differ in several aspects from that originating from the winter rainfall area. The plant has a simple structure and consequently spore, stoma and sporangia sizes, as well as the number per lamina was studied to determine if the species can be subdivided into two groups, e summer and e winter rainfall group, as was previously hypothesised. Univariate and bivariate methods were used to display the extent of variation within the species. Univariate analysis reflect variability of spore and stomata size, and the number of pinna pairs per lamina. Statistical analyses showed that interpopulation variation for these characters are often highly significant. Phonetic methods were used in the analyses of the data set and shows continuous variation in this species. This continuous variation in Schizaea pectinata could be linked to a phenotypic response to environmental differences between the two regions.

The genus Schizochilus, first described by Sonder in 1847 as an extra-tropical Southern African orchid, is based upon material collected by Ecklon and Zeyher in moist places in the Winterberg mountains. The main characters of the flower are a spurred, fleshy three-cleft lip; and free, erect sepals and petals, all three sepals being equal and the petals much smaller than the sepals. The type species, S. zeyheri Sond., is described as having a small number (2-3) of linear-oblong basal leaves and a spike of 16-20 small flowers. Sepals and petals are both noted as white, the sepals about 0,5 cm in length (2.5 lines) and marked with 3 rosy veins, the petals lanceolate and half the length of the sepals. The spur is "not much shorter than the labellum" and the ovary, "almost twice the length of the spur". The lip itself, obovate in outline, is covered with very small crystalline papillae, the lateral lobes being "somewhat shorter than title broader, obtuse intermediate lobe". There appears to be no mention of the basal tubercles or calli on the lip.

The cosmopolitan Asteraceae tribe Gnaphalieae, or paper daisies or everlastings, form a significant component of both the dry and cool temperate floras of southern Africa. Within this tribe exists a small Afrotemperate genus, Macowania, endemic to the grassland biome of South Africa and occurring almost exclusively within the Drakensberg region, apart from two disjunct species in North Africa. The age, relationships and geographic origin of Macowania is investigated in order to provide insight into the factors affecting speciation, especially uplift events, on this small Afrotemperate genus. A well-supported phylogenetic hypothesis based on both nuclear and chloroplast genes suggests that Macowania is sister to a clade corresponding to the Relhania clade s.s., and that these are in turn sister to a clade containing the genera Athrixia and Pentatrichia. Macowania is monophyletic only with the inclusion of the enigmatic monotypic genus Arrowsmithia, resulting in the future synonymy of Macowania with Arrowsmithia. The anomalous species M. pinifolia, previously part of the genus Athrixia, is placed in a polytomy with the Relhania s.s. clade and the remaining species of Macowania and Arrowsmithia. DNA sequence data could not be obtained for several Macowania species, including the taxa from North Africa. The placement of these species within Macowania is confirmed by means of a parsimony analysis of morphological characters against a molecular backbone constraint tree. One species, M. tenuifolia, is well-supported in two different placements within Macowania by chloroplast and nuclear DNA sequence data. The best position of this species is inferred by incongruence decomposition analysis and morphological affinities. Bayesian relaxed clock methods and ancestral area reconstruction using maximum likelihood and squared change parsimony estimate the age and ancestral area of the genus, and determine the timing and route of colonisation of the Drakensberg. Diversification within Macowania is consistent in timing with the uplift events during the Miocene and Pliocene that resulted in significant vertical movement in eastern South Africa, suggesting that colonisation of the high-elevation Drakensberg grassland by Macowania was promoted by uplift. The topographic heterogeneity and increased river action resulting from the uplift may also have promoted evolution into new habitats and potentially mediated the movement of the ancestor of Macowania into the Drakensberg region via riparian habitats.

The perennation of orchids is poorly understood, in particular that of the Orchidoidae. The understanding of perennation in the Orchidoidae is important because the root-stem tuberoid is used as the one character defining the Orchidoidae as a monophyletic group. The root-stem tuberoid has never been examined for variation before. This project focuses on perennial growth in the Diseae in order to study the structure and function of the root stem tuberoid in relation to other organs and to contribute to the understanding of Orchidoid phylogeny.

Different histories for forests in Southern Africa have been hypothesized from vegetation biogeography and pollen analysis. However, the history of forests is still controversial. Phylogeography uses gene genealogies to infer history of distributions. Two forest endemic moss species were sampled: Leptodon smithii; and Neckera valentiniana. Two gene regions were used, trnLF (chloroplast genome) and ITS1 (nuclear genome). Neckera valentiniana showed no variation from the populations sampled. Results from Leptodon smithii based on the trn and ITS region suggest that forests once were widespread, but then became fragmented. Dispersal corridors still exist between Southern Cape populations and Western Cape populations.

Character variation in Chaetobromus, a genus of palatable grasses endemic to the arid western areas of southern Africa, was used to derive a classification reflecting taxonomic and ecological pattern. The present study differs from earlier biosystematic investigations by its much more intensive approach to sampling, with 75 anatomical, morphological and cytological characters and 169 individual samples being used. The use of larger population samples permitted quantification of variation within populations, in addition to that among populations and groups. Phenetic methods revealed the existence of three groups, approximating three formerly described taxa and reflecting divergent ecological strategies in Chaetobromus. A lack of diagnostic field characters argues against their recognition at species level, and Chaetobromus Nees is here described as monotypic, the type species, C. involucratus (Schrad.) Nees, comprising three subspecies C. involucratus subsp. involucratus, C. involucratus subsp. villosus Verboom and C. involucratus subsp. dregeanus (Nees) Verboom. There is overlap among subspecies in most characters although many showed significant mean differences. Within subspecies, character variation appears to be homogeneously distributed with respect to population boundaries suggesting that these are likely to have little impact on sampling. An investigation testing the effect of sample strategy on variation capture and taxonomic group detection suggests that a sample of 10-15 specimens is likely to account for most variation present. Phylogenetically, Chaetobromus is included in the tribe Danthonieae, and, on morphological evidence, is probably basal to a clade containing Pentaschistis, Pentameris and Pseudopentameris. The genus appears to occupy a niche unique among the African danthonioids, favouring lime-rich, basic soils and a strongly-seasonal winter-rainfall regime with arid summers. Ecological differences among the subspecies are reflected in differences in growth form and vegetative and reproductive phenologies. The niche requirements of Chaetobromus may be adequately specific to explain the patchy distribution of the genus. Bibliography: pages 119-131.

Mechanisms for the generation of biodiversity in species-rich biomes such as rain forests remain unclear. Molecular phylogenies using DNA sequence data, calibrated with a temporal dimension offer a means of addressing this question, enabling the testing of different hypotheses on biogeographic histories and causes of diversification. Manilkara is a genus of trees in the Sapotaceae consisting of ~79 species distributed throughout the tropics (30 South and Central American, 35 African and 14 Southeast Asian). This species diversity in all major tropical regions of the globe makes it an ideal candidate for in-depth biogeographic studies. Maximum parsimony and Bayesian analyses of nuclear (ITS) and chloroplast (rpl32-trnL, rps16-trnK and trnS-trnFM) sequences were used to reconstruct a species level phylogeny of Manilkara and related genera in the tribe Mimusopeae. Manilkara, as currently defined, is not monophyletic due to the placement of three Asian taxa (M. fasciculata, M. dissecta and M. udoido), which are more closely related to the Madagascan genera Labourdonnaisia and Faucherea than to Manilkara s.s. and need to be re-circumscribed in a new genus. Letestua is nested in Manilkara and the genera Faucherea and Labourdonnaisia are not monophyletic. Nuclear and chloroplast datasets were mostly congruent, however, three instances of hard incongruence were demonstrated, suggesting chloroplast capture events. Bayesian analyses of ITS sequences using a relaxed molecular clock calibrated with fossils, focused on testing biogeographical hypotheses on the origin of Manilkara’s pantropical disjunct distribution and spatio-temporal diversification patterns on each continent. Mimusopeae, originated during the Eocene ~46-57 Ma and fossil evidence supports its existence in the boreotopical region of the northern hemisphere during this time. This suggests that the tribe may have evolved there and found refuge in Africa when Oligocene climatic cooling made higher latitudes uninhabitable for megathermal taxa. The subtribe Manilkarinae was resolved as ~42-36 Myo. These ages fall on the Eocene-Oligocene boundary and the crown node age coincides with the onset of Oligocene cooling and the closing of the boreotropical route. The genus Manilkara is estimated to have evolved ~36-33 Ma. The current distribution of the genus could not, therefore, have been the result of Gondwanan vicariance or migration through the boreotropics, but results instead support long distance dispersal as an important factor influencing the distribution of the group. Resolution along the backbone of the phylogeny is weak and the area of origin is, therefore, difficult to determine. However, all sister taxa to Manilkara are African and this suggests that the most likely explanation is an African origin for the genus with subsequent inter-continental dispersal during the Miocene. Manilkara spread from Africa to the Neotropics and Asia via at least three separate long distance dispersal events. A single lineage dispersed to the Neotropics ~27-21 Ma and spread across the Isthmus of Panama before its closure. Another lineage dispersed to Southeast Asia ~30-25 Ma from mainland Africa and subsequently diversified throughout the region. A third dispersal from Madagascar to the Sahul Shelf, occurred ~31-16 Ma in the M. fasciculata/dissecta/udoido lineage. In South America, diversification is consistent with both aridification and the rearrangement of drainage patterns in the Amazon basin as a result of Andean orogeny. The Atlantic coastal forest clade and the Amazonian clade of Manilkara split from one another ~14 Ma, at approximately the same time as the dry biomes of the Cerrado and Caatinga were forming between them. In Africa diversification coincides with Tertiary cycles of aridification and uplift of the east African plateaux. In Southeast Asia Wallace’s Line did not affect the dispersal of Manilkara. Instead, the limiting factor was the appearance of land in New Guinea ~10 Ma, which coincides with the dispersal and establishment of new taxa east of Wallace’s Line. Spatio-temporal patterns of diversification in Manilkara were compared to those of 34 other wet tropical genera which have intercontinental disjunctions. Ages of disjunctions ranged from the Eocene to the Pliocene, indicating that compilation of the tropical rain forest biome is a dynamic process which has been occurring throughout the Tertiary. Recent migration via long distance dispersal is a significant phenomenon in biome construction. Geo-climatic events have also been shown to be important drivers of diversification in all continental regions.

A unifying goal of plant systematics is in pursuit of a natural system that means phylpgenetic relationships. We can construct it by means of various characters. There are many arguments about generic circumscription of Pteridophyta. It¡¦s worth while to reexamine some characters, such as trichome. Trichomes have long been considered one of the most important characters by pteridologists. However, The study of trichomes in Taiwan is very rare. In the present study, trichome morphology is used to assess phylogenetic relationships among genera of Dryopteridaceae (sensu Kramer et al.) . The observation of trichomes focus on hairs on the lamina and scales on the base of stipes. Lamina surface hairs are classified into unicellular hairs, club-like unicellular glands, uniseriate hairs, spine-like hairs, appressed glandular hairs, uniseriate hairs with a glandular head and verruca. Stipe base scale margins are classified into entire, serrate, unicellular branch, uniseriate branch, multicellular branch with a glandular head, and dorsi-ventral branch. Color distribution and branch dimension of scales were also good differentiation characters. The main taxonomic conclusions are as follows: (1)Trichome characters support the distinctness of Nothoperanema, Peranema, Polystichm, Dryopsis, Ctenitis, Tectaria, Athyrium, Cystopteris, Acystopteris, and Woodsia; (2) Diplazium and Dryopteris are hererogenous and show little correaltion to exist system. The latter two genera need further research.

Abstract Senecio is one of the largest genera in the Asteraceae family with 28 Senecio species in New Zealand and over 1200 species worldwide. Native Senecio in the Canterbury region are typically naturally uncommon and exhibit extreme fluctuations in population size. Contrary to native Senecio, exotic Senecio in the Canterbury region are thriving. Why some exotic species thrive in a novel environment while native species decline has been an area of intense study since the era of Darwin. However, despite extensive study, we are still unsure about the underlying mechanisms of this phenomenon. This thesis looks at several hypotheses that have been proposed to explain differences in success between native and exotic species including four that have been frequently mentioned in the literature: phylogenetics, natural enemy release and biotic resistance, allopolyploidy and habitat modification. In order to determine if phylogenetic relatedness influences the abundance and distribution of Senecio species in Canterbury, DNA phylogenies of New Zealand’s Senecio were constructed using nuclear (ITS, ETS) and plastid (trnL, trnL-F and psbA-trnH) DNA sequences. The resulting cladograms were used to determine the areas of origin of New Zealand’s Senecio lineages, the identity of their closest relatives and lineages and species that are of allopolyploid origin. The data provided by the phylogenetic analyses was to provide context for analyses of ecological data of 86 native and exotic Senecio populations from the Canterbury region. My results indicate that phylogenetic relatedness is a poor predictor of the amount of folivory experienced by Senecio, although some natural enemies of native and exotic Senecio displayed a positive preference for Senecio depending on their clade. The strongest effects on Senecio and the occurrences of their natural enemies came from the surrounding land use which influenced the amount of folivory and the abundances of natural enemies on Senecio. Enemy release and biotic resistance were land use specific within Canterbury and by themselves cannot explain the variance in folivory when applied to a landscape scale. According to my results, the biggest factor influencing Senecio folivory, abundance and distribution in the Canterbury region is change in the surrounding land use.

Orientador: Vinicius Castro Souza / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T10:53:10Z (GMT). No. of bitstreams: 1 Silveira_DanielaSampaio.pdf: 13077358 bytes, checksum: 444d6c94d072cef289968c110c821bf3 (MD5) Previous issue date: 2009 / Resumo: Elaeocarpaceae inclui 15 gêneros, com aproximadamente 500 espécies distribuídas em regiões tropicais e subtropicais do globo, em com exceção dos continentes africano e europeu. O gênero Sloanea reúne 120 táxons, dos quais cerca de 40 ocorrem no Brasil em diversos tipos de vegetação, principalmente na Floresta Amazônica e na Floresta Atlântica. O presente trabalho refere-se à revisão taxonômica das espécies neotropicais extra-amazônicas de Sloanea. A realização deste estudo constou de levantamento bibliográfico, consulta aos acervos dos principais herbários nacionais e estrangeiros, e expedições de coleta em áreas de ocorrência natural dos táxons do gênero. De um modo geral, com base na morfologia externa, a caracterização de Sloanea compreende árvores de grande porte dotadas de sapopemas, folhas simples, flores com sépalas que podem ou não cobrir órgãos reprodutivos na fase pré-antese, estames com prolongamento do conectivo conspícuo, que pode ser agudo, acuminado ou filiforme, frutos cobertos por cerdas rígidas ou flexíveis, algumas vezes inermes. Na revisão foram definidas 19 lectotipificações aqui desginadas, quatro novas sinonimizações, um nome duvidoso e a constatação de cinco nomes ilegítimos e seis nomes nus. Foram identificadas 17 espécies na área de estudo, sendo seis desconhecidas para a ciência: S. fasciculate, S. filiforms, S. hatschbachii, S. petala, S. subssesilis, S. uniflora. / Abstract: Elaeocarpaceae includes 15 genera, witch approximately 500 species distributed in tropical and subtropical regions of the globe, except for African and European continents. Sloanea comprises 120 taxa, of witch about 40 occur in Brazil in several vegetation types, but mainly in the Amazon Forest and in the Atlantic Forest. This thesis revises the taxonomy of the neotropical species of extra-amazon Sloanea genus. This study consisted of literature review, consultation with the collections of major Brazilian and foreign herbaria, and collection expeditions in areas of natural occurrence of taxa of the genus. In general, based on external morphology, the characterization of Sloanea comprises large trees endowed with buttressed roots, simple leaves, flowers witch sepals that may cover or not the reproductive organs in pre-anthesis phasis, stamens with the connective continued into a small knob, acuminate, acute or filiform awn, fruit covered with rigid or flexible bristles, sometimes unarmed. In this thesis 19 lectotypes her designated were defined, and four new synonyms, one doubtful name, five illegitimate names and six nude names were found. From the 17 species that were identified in the studied area, six of them were unknown to science: S. fasciculate, S. filiforms, S. hatschbachii, S. petala, S. subssesilis, S. uniflora. / Universidade Estadual de Campi / Biologia Vegetal / Doutor em Biologia Vegetal