The Eastern Cape is regarded as the centre of diversity for Passerina, except for two species occurring in the outliers of eastern Africa. Ten species are endemic to the Cape Floristic Region and four are regarded as near endemics. A complete species-level phylogeny for Passerina utilising sequences from three plastid and one nuclear gene is presented. The loci sequences were rbcL, trnL-F, rps16 and ITS. Parsimony and Bayesian analysis yield identical relationships and two informal groupings are described. Passerina is well imbedded within the tribe Gnideae and not sister to it as previously suggested. The elevation of the subtribe Passerininae (under the tribe Gnidieae) to the monogeneric tribe Passerineae, is thus not supported. The age of the root node of Passerina was estimated to evaluate the widely held view that much of the diversification in the Cape occurred ca. 5Mya with the start of the Mediterranean climate. Contrary to this, the timing and the temporary dynamics of the radiation of Passerina indicated that the lineage is at least 18 million years old and that the diversification rate had declined slightly over the past 5 million years. In Passerina, it also appears that speciation has been largely allopatric with a high frequency of range shifts. / Dr. M. van der Bank

Lachnaea L. (Thymelaeaceae), a genus established in 1753, is endemic to the Cape Floristic Region (CFR) of southern Africa. It demonstrates a high level of regional endemism, with 55% of the species endemic to one of the six centres in the CFR. The first detailed taxonomic account of the genus was published by Meisner in 1840 based on the collections of Drège. Three sections were recognised, namely Sphaeroclinium Meisn., Conoclinium Meisn., and Microclinium Meisn., based mainly on the inflorescence structure. The circumscription of Lachnaea has been extended to include all five species previously placed in Cryptadenia Meisn. and at present 40 species and two subspecies are recognised. In this study a detailed species-level phylogenetic tree for Lachnaea was produced using 3 283bp of plastid DNA and 679bp of nuclear DNA for 38 accessions and various outgroups. The loci sequenced were trnL intron and trnL-F spacer, rbcL, rps16 intron and the nuclear gene ITS. Parsimony and Bayesian analyses yielded identical relationships and these are consistant with morphological data, producing the best-supported phylogenetic assesment currently available for the genus. Five informal groupings are also described in the study. The start of the diversification of Lachnaea was estimated at 7.2Mya with a major proliferation around 6Mya. Sympatric speciation in this genus appears to be plausible with patterns suggesting that altitudinal differences and pollinators have been involved in the speciation process. / Dr. M. van der Bank

Ph.D. / Pimelea Banks & Sol. Ex Gaertn. nom. cons. is a large genus consisting of 110 species, of which 90 species are endemic to Australia, 19 to New Zealand and one to Lord Howe Island. The genus has a great diversity of life forms, breeding systems and habitat. Its closest related genus is Thecanthes Wikstr. Thecanthes comprises five species of annual herbs occurring in the Philippines, New Ireland and northern Australia. Australasian Thecanthes and Pimelea are the only genera within sub-tribe Pimeleinae (angiosperm family Thymelaeaceae) and are characterised by the reduction to two stamens. Here I present the most comprehensive molecular phylogenetic study for Pimelea and Thecanthes. Sequences data from nuclear ITS rDNA and plastid rbcL, rps16, matK and trnL-F intergeneric spacer were used to reconstruct a phylogeny for these genera. I have produced 457 new DNA sequences (five genes and 150 taxa) for the present analyses. The resulting phylogeny was used to assess the taxonomic status of Thecanthes and to evaluate the relationships with Pimeleinae since previous studies indicated a close relationship between Pimelea, Thecanthes and species of Gnidia L. from tropical Africa. The morphological delimitation of sections within Pimelea, the biogeography and the radiation of the genus have been revaluated. Pimelea was found to be monophyletic. It was concluded that Pimelea and Thecanthes are congeneric; consequently a paper has been submitted transferring all species of Thecanthes into Pimelea and making the new combination Pimelea filifolia (Rye) Motsi & Rye. Data analysis revealed very low sequence variation within the subtribe Pimeleinae. This suggested a rapid radiation of the genera, which was confirmed by my molecular dating analyses. Based on molecular clock techniques, I calculated the following ages for the origin of Pimelea: 4.1 mya for New Zealand Pimelea spp. and 13.38 mya for other Pimelea spp. The molecular data also indicated that Pimelea and South Africa Gnidia have a direct common ancestor. I also show that the New Zealand Pimelea are derived and dispersed from Australian