The monophyly of the genus Brachycorythis has been tested. The phylogeny of the African genera of Orchidinae - Orchideae - Orchidaceae (Schwartzkopffia, Brachycorythis, Neobolusia, Schizochilus, Dracomonticola, Holothrix and Bartholina is estimated with special attention to phylogenetic positions of Brachycorythis and Neobolusia. Pollen surfaces of twelve of the species are examined. Thirty-eight morphological and anatomical characters for 25 species of the species mentioned above are cladistically analysed and the stability of the different clades of the most parsimonious trees determined using various clade stability indices. The current delimitation of the Southern African Orchidae genera, with Neobolusia and all the other genera being independent from Brachycorythis is supported. Pollen surface ornamentation also shows the only species of Neobolusia examined for this (N. tysonii) as being quite different from the rest of the genera studied in having intectate pollen whereas the rest have semitectate pollen. This has further indicated support for the independence of Neobolusia from the genus Brachycorythis.

No description available.

Molecular sequence data from two noncoding regions of DNA (ITS AND TRNL-F) were used to produce a phylogeny for the genus Tribolium and its African and Australasian allies. Topological comparisons of the combined molecular data with the appended existing morphological tree were made. A significant incongruence was revealed. Molecular data indicate that Tribolium is paraphyletic. The formally defined sections: Uniolae, Acutiflorae and Tribolium have been retrieved by the molecular data. The analysis retrieved Karroochloa as polyphyletic. Monophyly of Schismus is strongly supported. The Australasian species form a monophyletic clade. Data support early divergence of the Merxmuellera species and Pseudopentameris macrantha.

Two Trichilogaster sp. (gall-forming wasps) have been introduced against Acacia longifolia and Acacia pycnantha in the Cape. Trichilogaster acaciaelongifoliae has reduced both seed production (by between 85 and 100% in the Cape) and vegetative growth in Acacia longifolia. The aim of this project was to determine whether the galls and buds of Acacia pycnantha have significantly different energy values, and to determine what affect this has on the plant. There was no significant difference between gall and bud energy values (p=0.029, df-=7, alpha=0.05) but gall energy values were, on average, 9.35% lower than those of bud material. The mass of galls increased steadily throughout the year while bud material remains at the same weight. The resource loss to the plant caused by the galls is dependent on the size and number of galls present on the tree. Even with similar energy values per unit dry mass there were many more grams of gall material on a tree than bud material and thus they would demand more resources to be invested in the gall material. An important factor concerning the effect galling has on A. pycnantha is the time during the trees reproductive cycle that galling occurs. It has been shown that when galling coincides with the season when the most energy is channelled into reproduction that the damage to the tree is heaviest.

Ten species of coralsnakes are known from Bolivia, and the ranges of an additional four approach Bolivia's northeastern border. Ranges of several species are expanded to accommodate recently collected material. Coralsnakes with characteristics thought to be diagnostic of Micrurus tricolor do not occur in Bolivia, and this species is considered to be a junior synonym of Micrurus pyrrhocryptus. Micrurus frontifasciatus is returned to the synonymy of M. lemniscatus. Some specimens previously referred to M. frontifasciatus, are described as the new species Micrurus serranus, which is apparently restricted to dry intermontane valleys of the Andes above 1200 m. Putative subspecies of M. spixii occur in sympatry within Bolivia and differ from one another by a suite of morphological characters. Accordingly, we recognize M. spixii and M. obscurus as distinct species. Characteristics used to define M. s. princeps appear to be clinal, and this taxon is considered to be synonymous with M. obscurus. Micrurus corallinus, M. ibiboboca, and M. tschudii do not occur in Bolivia, despite earlier reports to the contrary. Claims that melanism increases with age in some species are not supported by our observations.

The moss genus Andreaea possesses some sporophyte features that resemble liverworts or mosses and some gametophyte features resembling only the mosses, whereas other features are unique. This thesis presents the first phylogenetic study of the genus, based on both morphological and molecular evidence. Gametophyte and sporophyte characters were utilised for cladistic analysis. Sequence data was also generated from two chloroplast gene loci, the trnL-F intergenic spacer and the coding region of the ribosomal protein S4 (rps4). Separate morphological and molecular analyses produced topologies incongruent in certain parts and congruent in others. However, their combined analysis was better supported and therefore offered a more reliable hypothesis. The inferred phylogeny supported the monophyly of the genus. However, the monophyly of most infra-generic groups was largely contradicted. The putative subgenus Chasmocalyx is monotypic with A. nivalis as the sole species, whereas A. australis and A. nitida were resolved within the more broadly circumscribed section Andreaea of subgenus Andreaea. The section Nerviae of subgenus Andreaea is more narrowly circumscribed. A. blyttii (presumed member of section Nerviae) forms a basal lineage separate from all other species and apparently should constitute another monotypic subgenus. A. wilsonii (traditional Subgenus Acroschisma) is embedded within section Andreaea of Subgenus Andreaea. A. subulata, a presumed member of the section Nerviae (Subgenus Andreaea) is included in the section Andreaea. Character state optimisation has shown that falcate leaves, possession of a leaf costae and medium sized spores are some of the pleisiotypic features within Andreaea. However, a number of phylogenetic questions, regarding infra-generic relationships of the genus still remain unanswered. Directions for further future work have been suggested.

Bibliography: leaves 106-120. / The genus Euphorbia is morphologically diverse and nearly cosmopolitan. Both succulent and non-succulent species are found within the genus. Succulent species are found in most arid and semi-arid areas of the world, but show their greatest concentration and diversity of form in Southern Africa especially the Cape Floristic Region. The monophyly and phylogenetic relationships of the genus Euphorbia were investigated based on morphology and on sequences of the nuclear ribosomal internal transcribed spacer (ITS) and chloroplast psbA-trnH intergenic spacer. Fifty-one species of Euphorbia and four outgroups from Monadenium and Ciutia were sampled. Matrices were analysed using parsimony and maximum likelihood methods. Separate analyses of data partitions resulted in largely non-conflicting topologies; therefore the data sets were combined. The results showed that the genus Euphorbia is paraphyletic and four monophyletic groups with a number of putative synapomorphies defining each clade were strongly supported in most analyses. The Cape succulents fall into two well-supported clades. The results thus provided evidence for Cape radiations. Most analyses indicated that one of the Cape groups is sister to a group consisting of species mostly from Southern Africa (excludingthe Cape Region). Increased taxon sampling is however needed to clarify relationships within the monophyletic groups. Morphological characters recovered broad groups within Euphorbia. Due to inadequate sampling in some sections, modifications in the present classification of Euphorbia are not suggested. The total evidence tree was used to explore morphological character evolution through character state optimisations. The presence of root tubers was homoplasious and this character state is hypothesized to have arisen at least five times under current sampling. Cylindrical stems, conspicuous leaves and absence of leaf spines were some of the pleisiomorphic states observed in some sampled members of the genus Euphorbia. Although the results obtained in the CUlTent study are preliminary, they have created further challenges for future studies of phylogenetic relationships and morphological character evolution in the genus Euphorbia.

Includes bibliographical references. / This study examines the effects of fragmentation on bryophyte diversity in renosterveld vegetation of South Africa's west coast. The main objectives of this study are to; Document bryophyte species assemblages in remnant fragments of renosterveld vegetation, investigate the effect of fragment size, isolation and heterogeneity on bryophyte diversity patterns in renosterveld, determine the extent to which fragments are nested and evaluate the extent to which existing conservation measures are appropriate for the long-term survival of the bryophyte flora in this vegetation type. Seventy-two bryophyte species were recorded from 23 fragments ranging from 0.1 to 102 hectares.

Hoodia Sweet ex Decne is revised to contain 13 species which are divided into 2 sections. Sect. Hoodia contains H.currorii, H.dregei, H.gordonii, H.juttae and H.parviflora. Sect. Trichocaulon contains H.alstonii, H.flava, H.mossamedensis, H.officinalis, H.pedicellata, H.pilifera, H.ruschii and H.triebneri, all except H.ruschii formerly constituting the section "Eutrichocaulon", the so-called "spiny" species of Trichocaulon. The remainder of Trichocaulon, the section Cactoidea, is transferred to Lavrania Plowes. This genus then consists of the monotypic section Lavrania (L.haagnerae) and Sect. Cactoidea containing L.cactiformis, L.marlothii, L.perlata and L.picta.

Bibliography: leaves 86-97. / Lepfodon smithii (Leptodontaceae) and Pterogonium gracile (Leucodontaceae) are widespread and disjunctly distributed moss species, that in South Africa are confined to forest patches believed to be relics of vast forests that existed before the Pleistocene glaciation period. These two species exhibit similar distribution and ecologies and frequently co-occur. Wardia hygrometrica is a southwestern Cape endemic that is restricted to streams within the kloofs that the forests generally occupy. In an attempt to trace the species histories and their subsequent colonization of forest patches, two molecular markers, internal transcribed spacer (ITS) nuclear rDNA and trnL-F cpDNA were employed.