Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 119-134).

Thesis (M.Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 119-134) Also available in print.

Thesis (Ph. D.)--School of Biological Sciences, Faculty of Science, University of Sydney, 2006. / Title from title screen (viewed 15 January 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Biological Sciences, Faculty of Science. Includes bibliographical references. Also available in print form.

M.Sc. (Botany) / A Taxonomic study of the genus Heteromorpha Cham. & Schlechtd. (Apiaceae) The species delimitation in Heteromorpha Cham. & Schlechtd. has until now been unsatisfactory, and the relationship and placement unclear for several plants which have variously been referred to either H. arborescens (Spreng.) Cham. & Schlechtd. or H. trifoliata (Wendl.) Eckl. & Zeyh. The present revision has resulted in the recognition of seven species (including seven varieties) across the African mainland from the south-western Cape to the Yemen Arab Republic, and westwards to Nigeria. Eight species from Madagascar are excluded. The name H. stenophylla Welw. ex Schinz is reinstated and H. transvaalensis Schlechter & H. Wolff is considered a variety of the latter. A new species, H. occidentalis Winter, is described. A narrower view of H. arborescens (Spreng.) Cham. & Schlechtd. than that of recent authors is applied, and the species is subdivided into five varieties to accommodate the diversity. Two of these are described for the first time, namely var. frutescens Winter and var. montana Winter. H. stolzii H. Wolff is added to the synonymy of H. involucrata Conr., and the circumscription is broadened to accommodate other central African forms of the species. Data are analyzed cladistically and the supposed phylogeny is presented in the form of a cladogram. Keys to the recognized species and varieties respectively, as well as the known geographical distribution for each of the taxa, are presented.

The generic boundaries and relationships of Annesorhiza Cham. & Schlechtd., Chamarea Eckl. & Zeyh. and two deciduous species Peucedanum L. (P. filicaule and P. triternatum) have until now been unsatisfactory. This is mainly due to the fact that the species are inconspicuous, poorly known and poorly represented in herbarium collections. The present study has resulted in the recognition of three sections and 21 species within a broadened concept of Annesorhiza. The genus Chamarea is included in Annesorhiza as a section and P. filicaule and P. triternatum are transferred to Annesorhiza to make the genus Peucedanum more uniform. A new section, Ternata Vessio et al., and a new species, A. elsiae Vessio et al., are described. Morphological, anatomical, phenological and geographical evidence is used to investigate the relationships between the genera and species. These characters are discussed and illustrated. The anatomy and structure of leaves (pinnate or ternate), as well as the symmetry, morphology and anatomy of the fruit, and the size and shape of sepals proved to be of taxonomic value in distinguishing between taxa. The data is analysed cladistically, using Glia Sond. as an outgroup. The analyses show that all members of the study group form a monophyletic group characterized by deciduous leaves and the periodic replacement of fleshy roots. Within this larger group (Annesorhiza sensu lato) three monophyletic entities can be distinguished, each of which is treated as a formal sections: Section 1. Annesorhiza sensu stricto (including all except three species of the genus Annesorhiza sensu stricto); Section 2. Chamarea (including all except two species of the genus Chamarea); Section 3. Ternata Vessio et al. (a new section to accommodate all species with ternate leaves – three from Annesorhiza sensu stricto, two from Chamarea and two from Peucedanum). A formal taxonomic treatment is presented, including keys to the recognized sections and species, correct nomenclature, typification, descriptions and distribution maps. / Dr. P.M. Tilney

Recent molecular studies (Plunkett et al., 1996b, 1997; Downie et al., 1999, 2001; Plunkett, 2001; Valiejo-Roman et al., 2002) on the family Apiaceae have shown that the existing classification system is largely artificial and that genera and tribes are in need of considerable re-arrangement. The fruit morphology and anatomy of 212 genera and 267 species of the family were studied. This study shows that a new interpretation of traditional morphological evidence will not only help to improve our understanding of the newly emerging molecular phylogeny of the Apiaceae, but also be useful for systematic studies of the family. Fruit structure, the very wide commissure and thick mesocarp as is found in Araliaceae fruits especially, provides some support for the molecular systematic study (Plunkett, 2001) in which it was proposed to move Hydrocotyle L. from Drude’s (1898) Hydrocotyloideae Link. to be a sister of ‘core Araliaceae’. Fruit structural evidence from selected Araliaceae suggests that the Araliaceae and Apiaceae are not fundamentally different and that the two families, as currently circumscribed are linked by taxa sharing character states of both families. Hydrocotyle shows features of both Araliaceae and Mackinlayeae. Two genera, Myodocarpus Brongn. & Gris. and Mackinlaya F. Muell., should be moved from Araliaceae to respectively the Myodocarpeae R. Vig. and Mackinlayeae R. Vig., which cladistically are placed below the Apiaceae. The former has median wings and large vittae and the latter has crystals present in the innermost portion of the mesocarp adjacent to the endocarp. These features are usually absent in Araliaceae but may be present in Apiaceae. A study of fruit features of all other genera with laterally compressed mericarps of Drude’s (1898) Hydrocotyloideae (except for Hydrocotyle) suggests that it may be possible to move these taxa to Mackinlayeae because they share not only laterally compressed mericarps, but a similar crystal position and arrangement of ventral bundles (there are cells between the ventral bundles, but a true carpophore is absent), as with Mackinlaya. In the present study the subfamily Mulinoideae [Plunkett et al. (2004) has now independently described this subfamily as the Azorelloideae Plunkett & Lowry subfam. nov. ined.] is proposed and used for Drude’s (1898) Mulineae DC. The Mulinoideae includes three groups, viz. the Klotzschia Cham., Azorella Lam. and Bolax Commerson ex Jussieu groups. The mericarps of the genera in the Klotzschia group may have five prominent ribs and a very wide commissure. In the Azorella group the lateral ribs are small and the marginal ribs may be prominent or winged and the commissure narrow. In the Bolax group the mericarps have more prominent lateral ribs or wings and the marginal ribs are small or undeveloped. The commissure is very narrow. Crystals may be present in the Klotzschia group. They are usually absent in the Azorella group and present in most genera of the Bolax group. These results partly support a molecular study (Plunkett, 2001), in which three groups: the Klotzschia, Azorella and Bowlesia groups, were indicated. The subfamily Saniculoideae is unique in fruit structure. Intrajugal oil ducts are present and there are sometimes some small vittae scattered in the mesocarp. Crystals are dispersed in the mesocarp. Lagoecia L., which has vallecular and commissural vittae, should not be grouped in Saniculoideae but rather be positioned with Apioideae as was indicated by a molecular study (Plunkett et al. 1996; Downie et al., 2001; Valiejo-Roman et al., 2002). Several African genera, including Lichtensteinia Cham. & Schltdl., Marlothiella H. Wolff, Arctopus L., Polemanniopsis B.L. Burtt and Steganotaenia Hochst, have only large intrajugal oil ducts as in Saniculoideae (Steganotaenia also has some small vittae scattered in the mesocarp). A slightly lignified endocarp may be present in most genera (except in Marlothiella) and crystals are present in Lichtensteinia and Marlothiella as in Saniculoideae and absent in other genera. It is proposed that these taxa be moved from Apioideae to near the Saniculoideae as different groups: the Arctopus, Polemanniopsis and Lichtensteinia groups (the latter includes Marlothiella), in addition to the Saniculoideae sensu stricto. This corresponds to a large extent with DNA sequence data (Downie & Katz-Downie, 1999; Plunkett, 2001). The ‘basal Apioideae’ is morphologically poorly defined but can be recognized by a combination of plesiomorphic characters, such as the woody habit, heteromorphic fruits, deciduous leaves and poorly developed carpophores. The most reliable difference between this group and the genera of ‘remaining Apioideae’ is the dispersed crystals in the mesocarp as in Saniculoideae. In ‘basal Apioideae’, DNA studies (Downie et al., 2001; Plunkett, 2001) indicated that the Heteromorpheae Downie & Watson include five endemic African genera: Anginon Raf., Dracosciadium Hilliard & B.L. Burtt, Glia Sond., Heteromorpha Cham. & Schltdl. and Polemannia Eckl. & Zeyh. The fruit study shows that in these genera laterally-winged mericarps (of heteromorphic fruits) and lignified endocarps and mesocarps may be present as well as crystals dispersed in the mesocarp and ventral bundles usually becoming free. Some other endemic African and Madogascar genera, viz. Andriana B-E. van Wyk, Cannaboidea B-E. van Wyk, Pseudocannaboides B-E. van Wyk, Pseudocarum C. Norman and Tana B-E. van Wyk, should also be placed in, or close to, the Heteromorpheae because they have crystals dispersed in the mesocarp and ventral bundles usually becoming free as in some Heteromorpheae. In the Annesorhiza Cham. & Schltdl. group (Annesorhiza and Chamarea Eckl. & Zeyh.), laterally-winged fruits (in heteromorphic fruits), a distinct hypoderm and a lignified endocarp may be present. The monotypic genus Molopospermum W.D.J. Koch is related to Annesorhiza (Downie, personal communication to B-E. van Wyk and P.M. Tilney); it has lateral wings on one of the two mericarps and an abundance of crystals in the mesocarp. The mericarps of the Bupleureae Spreng. may have irregular vittae as in Saniculoideae sensu stricto. All these fruit features are present in the ‘basal Apioideae’ and may be found in Saniculoideae and related groups. Remaining Apioideae differs from the genera of ‘basal Apioideae’ in the absence of dispersed crystals in the mesocarp and various other characters that occur alone or in combination (see above). Eight tribes (including some subtribes) and seven additional clades in ‘remaining Apioideae’ were defined by Downie et al. (2001). The circumscription of some of the tribes, subtribes and clades distinguished by Downie et al. (2001) on the basis of DNA data receive support from fruit structure. These taxa include tribes Aciphylleae and Echinophoreae, subtribes Daucinae and Torilidinae, and clades the Arracacia, Conioselinum and Heracleum clades. The present study shows that Drude’s (1898) system has significant taxonomic value, although many problems are present in his Hydrocotyloideae and Apioideae. These problems may have arisen because some fruit characters were not available, were overlooked, ignored or over-emphasised. Although some of Drude’s groups will be retained in a new system, a clear break from the Drude system is indicated by molecular systematics. This study suggests that taxonomically important fruit characters are wing configuration, presence or absence of intrajugal oil ducts and vittae and their size, presence or absence of crystals and their positions, possible lignification of the endocarp, and the arrangement and position of ventral bundles that may or may not form free carpophores. Therefore, evidence provided by fruit structure, if properly interpreted, can help to support and strengthen the newly emerging molecular phylogeny of the Apiaceae and facilitate understanding of the evolution of taxa in the family. / Prof. B.E. van Wyk

D.Phil. (Botany) / A taxonomic revision of the genus Centella is presented that is based on vegetative and reproductive characters. Genetic data was included in the extensive research ofpossible hybridisation. Hybridization as a possible mechanism of evolution may account for the lack of conguence between taxonomic characters in Centella. Phylogenetic and phenetic methods of analysis were used to explore the relationships among species. The results show that Centella is a particularly difficult genus, with many ofthe problems experienced at species level being a reflection ofthe problematic nature of the Apiaceae. The taxonomic treatment includes nomenclature, synonymy, typification, diagnostic characters, detailed illustrations and geographical distribution of all 45 species that are recognized. Keys to the subgenera, sections and species are provided. The revision includes several taxonomic and nomenclatural changes. The genus is subdivided as follows: Subgenus Trisanthus Subgenus Solandra Subgenus Centella 1 species 4 species Section Erianthae Section Tri/obae Section Centella Section Virgatae 9 species 3 species 16 species 12 species The following 13 new species were described: C. annua, C. calcaria, C. rotundifolia, C. umbellata, C. ternata, C. crenata, C. cryptocarpa, C. gymnocarpa, C. pi/osa, C. brachycarpa, C. dolichocarpa, C. thesioides and C. glauca. One ofthese species C. cryptocarpa, has been collected for the first time. Centalla rotundifolia, C. cordata and C. longifolia were elevated to species rank and C. rigescens was reinstated as a species of Centella. The number of varieties was significantly reduced and variation within the species is mostly described informally. Varieties were retained for only two species. New varieties are: C. tridentata var. tridentata, C. tridentata var. littoralis, C. tridentata var. hermanniifolia, C. tridentata var. dregeana, C. graminifolia var. graminifolia, C.graminifolia var. natalensis and C. graminifolia var. stipitata.

Generic circumscriptions within the large polymorphic genus Peucedanum (family Apiaceae, subfamily Apioideae) have long been regarded as one of the last major challenges in the taxonomy of the family (Burtt 1991; Pimenov & Leonov 1993). Recent molecular phylogenetic studies have shown that the African species of Peucedanum form a distinct clade completely separate from the superficially similar Eurasian species. As a first contribution towards a re-evaluation of generic concepts, all the species occurring within the Cape Floristic Region were revised. A new generic classification system is presented for the 17 species here recognised. The two woody groups are described as two new genera viz. Nanobubon (2 spp.) and Notobubon (12 spp.). The herbaceous genus Cynorhiza is reinstated and expanded to include two additional species, one of which is newly described herein. New combinations for 15 of the 17 species are made and 7 taxa/species are reduced to synonymy. Cladistic analyses of both morphological/anatomical and gene sequence data (ITS) were performed to investigate infra- and inter- generic relationships. Keys, complete nomenclature, typification, descriptions as well as geographical distributions for all of the new genera and species are presented. / Prof. B.E. Van Wyk Dr. P. M. Tilney

M.Sc. (Botany) / Morphological, anatomical, palynological, cytological, phenological and geographical evidence are used to investigate relationships between the species of Anginon. These characters are discussed and illustrated. Characters of' the genus Glia Sond. were also studied and the genus is shown to be an obvious outgroup in a phylogenetic analysis. Despite the paucity of characters and the variability of character states in the genus Anginon, it is possible to give here a summary of character evolution as interpreted within the genus and also an explicit hypothesis (cladogram) of phylogenetic relationships amongst the species. Especially, the study of the fruit anatomy has resulted in a better understanding of taxonomic relationships at the generic and infrageneric levels. A formal taxonomic treatment is presented, including a key to the species, correct nomenclature, typification, descriptions and distribution maps.

The genus Heracleum (Apiaceae) includes 65-70 species, and is distributed across the Northern Hemisphere from North America to East Asia (Pimenov & Leonov, 1993). The Sino-Himalaya region (Nepal eastwards to SW China) is one of the most important distribution areas of Heracleum (with 10 species in the Himalaya and about 30 species in China). This thesis integrates a series of studies on the systematics of Sino-Himalayan Heracleum including allied taxa and a taxonomic revision of Nepalese Heracleum species. The taxonomic value of the various morphological characters used in Heracleum is generally discussed and potentially important fruit morphological characters investigated alongside. Several characters were found to be distinctive, constant out of taxonomic importance. These included extent of development of the lateral wings, presence/absence of epidermal hairs, hair types, and the transverse sectional arrangement of the mericarp, including position of sclerenchyma of vascular bundles, rib development, pattern of endosperm, distribution of vittae and thickening of wing margins. Based on these characters, Heracleum was divided into at least 5 types that are also supported by molecular data (ITS DNA sequences). In order to evaluate the monophyly of Sino-Himalayan Heracleum, and clarify the species relationships within this group, sequences of ITS, rps16 intron, and psbAtrnH spacer of Heracleum and related genera were studied. The resulting data matrix was analyzed using Maximum Parsimony and Bayesian analysis. Both ITS and rps16 intron regions show a good resolution of phylogenetic relationships down to species level. However, although psbA-trnH region has been successively tested in other plant families, it failed to resolve relationships among the major Heracleum clade. Only higher level resolution was successful. The results of our comparative phylogenetic study confirmed that the “Major Heracleum clade” (Sensu Downie) remains monophyletic. Within this clade at least six major lineages are defined: Heracleum, Malabaila-Pastinaca, Zosima, Semenovia, Tordylium, and Tordyliopsis. The Sino-Himalayan Heracleum lineage is seen to comprise three distinct sub-lineages (Heracleum group I, II and III) including several European Heracleum species. Heracleum is thus not monophyletic. Generic segregates of Heracleum proposed in past classifications,such as Tetrataenium, can be correlated with these subclades. These phylogenies also helped resolve the taxonomic placement of some enigmatic taxa such as Tordyliopsis brunonis and Heracleum millefolium. These molecular data provide valuable characters for inferring relationships within the Sino-Himalayan Heracleum. A taxonomic account of the species of Heracleum in Nepal is presented including a key to identification of the species is produced. A reinterpretation of the taxonomy of Sino-Himalaya Heracleum is presented based on these results including an account of the Nepalese species.