Cron, Glynis Valerie2006-11-012006-11-012006-11-01http://hdl.handle.net/10539/1584Student no:7719196 PhD thesis 2005 Faculty of Science, School of Animal, Plant and Environmental Sciences.This study aimed to investigate the phylogeny of Cineraria L. to elucidate its position in the tribe Senecioneae (Asteraceae), to delimit its generic and species boundaries, explore species relationships (infrageneric structure) and produce a monograph of the genus. It also aimed to examine its distribution, phytogeographic affinities, levels of rarity and endemism in Cineraria, to identify some of the factors contributing to rarity in Cineraria and to highlight implications for conservation. Phylogenetic analyses were performed using morphological and molecular (DNA sequence) characters to elucidate relationships within the genus and between Cineraria and selected related genera in the subtribe Senecioninae. The phylogenetic species concept was applied - suites of diagnostic characters were used to characterise species. The phenetic approach, using Cluster Analysis and Principal Coordinates Analysis, was applied to investigate variation in two highly variable species, C. deltoidea Sond. and C. lobata L’Hér. Species distributions were mapped and the number of species per degree square was plotted for southern Africa to identify centres of diversity and endemism. Rare species were identified and categorised according to Rabinowitz’s criteria of geographic range, habitat specificity and local population size. Cineraria now has a more homogenous generic concept, characterised as herbs or subshrubs with palmately veined leaves, radiate, calyculate capitula, penicillate style apices and obovate, compressed cypselae with two distinct margins or wings and a substantial carpopodium. Eleven species have been removed from the genus and two new genera, Bolandia Cron and Oresbia Cron & B.Nord. have been established to accommodate three of the species. Two species have been reassigned to and another reinstated in Senecio L. The affinities of five species remain unresolved. Cineraria now comprises 35 species with four new subspecies and two new varieties recognised. Eight species have been placed in synonymy and five new species have been described during this revision. The status of C. deltoidea as a single, highly variable species, widespread throughout the eastern mountains of Africa, has been confirmed. Cineraria lobata has been shown to be a very variable species and the geographic and morphological variation has been formally (and informally) recognised. No infrageneric classification has been applied to Cineraria as a robust phylogeny of all the species has yet to be hypothesised. A southern African origin for Cineraria in the Western and/or Eastern Cape is postulated, based on the current distribution of the sister genus Bolandia and Cineraria mollis DC. iv Cineraria appears to have undergone rapid speciation fairly recently, as indicated by the lack of variation in the molecular data analysed, with reticulate evolution playing an important role in its evolutionary history (as seen by the lack of congruence between the chloroplast and nuclear DNA sequences). The centre of diversity of Cineraria is the KwaZulu-Natal Midlands, part of the Maputaland-Pondoland Centre of endemism in southern Africa. Cineraria has an afromontane affinity, and fifteen species endemic to specific mountains or regions of endemism and five near-endemics have been identified in Cineraria. Eleven species have been shown to be rare (in the sense of low abundance, restricted range and high habitat specificity), however only five are considered to be threatened as indicated by IUCN Red Data Criteria. However, at least seven species are Data Deficient and require further investigation. Causes of rarity in Cineraria are linked to narrow habitat specificity, particularly soil or rock type and/or altitudinal range.3149252 bytes3924446 bytes2885366 bytes2203823 bytes3432944 bytes3338331 bytes2976296 bytes3473244 bytes2821163 bytes2849089 bytes3164110 bytes2114035 bytes2701773 bytes2452219 bytes3063259 bytes2943755 bytes3840063 bytes2789906 bytes2584473 bytes3047255 bytes4074821 bytes2542440 bytes2050508 bytes3467313 bytes3077841 bytes3266413 bytes2247813 bytes1681329 bytes2646087 bytes1885522 bytes3653576 bytes25368554 bytes8831427 bytes17104843 bytes26883379 bytes12106506 bytes1633214 bytes1689999 bytes781616 bytes388802 bytes76018 bytes774337 bytes16646605 bytes3730866 bytes1698618 bytes4504170 bytes1729908 bytes141131 bytes223373 bytesapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfenmultivariate analysismonographreticulate evolutionmolecular and morphological phylogeneticsThesis