Phylogenetics and taxonomy of the G o r t e r i a c l a d e (Asteraceae - Arctotideae) Frida Stångberg Phylogenetics and taxonomy of the Gorteria clade (Asteraceae-Arctotideae) Frida Stångberg ©Frida Stångberg, Stockholm University 2014 Cover illustration: Gorteria parviligulata. Photo by Frida Stångberg ISBN 978-91-7447-896-9 Printed in Sweden by Universitetsservice US-AB, Stockholm 2014 Distributor: Department of Ecology, Environment and Plant Sciences “…Thule hujus australis gazas speciosas detegendi gratia, lætus cucurri, sudavi et alsi.” C.P. Thunberg Abstract This thesis deals with the systematics of the Gorteria-Gazania-Hirpicium- clade within the tribe Arctotideae-Gorteriinae in the angiosperm family As- teraceae. The group is found in southern Africa, with many representatives in the Greater Cape Floristic Region in South Africa, an area known for its high species richness and endemism. Specifically, species delimitation within Gorteria and its intergeneric relationships to Hirpicium and Gazania were investigated. Previous phylogenetical studies showed that the two shrubby Hirpicium alienatum and H. integrifolium were more closely related to the herbaceous genus Gorteria than to remaining species of Hirpicium. During field studies additional proof of their affinity was found when these two, like Gorteria, were found to have capitulum diaspores. Gorteria was phylogenetically investigated with a large number of samples from different populations of G. diffusa, a species showing striking variation in ray floret coloration. The study showed that the current division of the genus into three species (Gorteria corymbosa, G. diffusa and G. personata) was not supported and it was also shown that the two Hirpicium species were not sister to but nested within a paraphyletic Gorteria. The necessary nomenclatural changes were made including the new combination Gorteria alienata but left remaining species of Hirpicium unassigned to a genus be- cause the type of Hirpicium was included in Gorteria. When the intergeneric relationship between Gorteria, Gazania and the re- maining species of Hirpicium were investigated in detail it was shown that an additional four species of Hirpicium had also evolved from an ancestor within Gorteria. The generic name Berkheyopsis was resurrected for the morphologically deviating Hirpicium echinus while a new genus, Roessleria, was described for the remaining species of Hirpicium. There was high sup- port for a monophyletic Gazania even though the relationship among the genera was unresolved. List of papers This thesis is based on the following papers, referred to in the text by their Roman numerals. I Stångberg F.K. 2009. Diaspore capitula in Hirpicium supports close evolutionary relationship to Gorteria (Asteraceae– Arctotideae). South African Journal of Botany 75: 600–605. II Stångberg F., Ellis A.G. & Anderberg A.A. 2013. Evolutiona- ry relationships in Gorteria: A re-evaluation. Taxon 62: 537– 549. III Stångberg F. & Anderberg A.A. 2014. Morphology and taxo- nomic reclassification of Gorteria (Asteraceae). Willdenowia 44: 97–109. IV Stångberg F. & Anderberg A.A. Intergeneric relationships in the Gazania-Gorteria-Hirpicium clade of Arctotideae- Gorteriinae, with description of a new genus, Roessleria. Manu- script. Published papers are reproduced with permission from the publishers. Disclaimer: A number of new combinations and a new generic name are outlined in the manuscript that constitutes paper IV. It is not of the author's intention to publish the names in this thesis. All Papers were written by Stångberg with comments and suggestions from the co-authors. Stångberg has conducted all field work, sequence alignments phylogenetic analyses and taxonomical treatments and generated all new sequences for Paper II. Contents Introduction .................................................................................................. 13 Material and Methods .................................................................................. 18 Results and Discussion................................................................................ 20 Concluding remarks ..................................................................................... 24 Svensk sammanfattning (Swedish summary).............................................. 26 Tack! ............................................................................................................ 30 References................................................................................................... 33 Abbreviations BM The Natural History Museum (British Museum) BOL University of Cape Town (Bolus Herbarium) CCR The Core Cape Subregion DNA Deoxyribonucleic acid & al. (et al.) Et alii, and others e.g. Exempli gratia, for example ECR The Extra Cape Subregion ETS External Transcribed Spacer G-DC Conservatoire et Jardin botaniques de la Ville de Genève (Candolle’s herbarium) GCFR The Greater Cape Floristic Region ITS Internal Transcribed Spacer K Royal Botanic Gardens (Kew) LINN Linnean Society of London NBG South African National Biodiversity Institute, Cape Town (Compton Herbarium) ndhF NADH dehydrogenase subunit F P-JU Muséum National d'Histoire Naturelle (Jussieu’s herbarium) PRE South African National Biodiversity Institute, Preto- ria rps16 Ribosomal protein S16 S Swedish Museum of Natural History SEM Scanning electron microscopy psbA Photosystem II protein D1 trn Transfer ribonucleic acid UPS Uppsala University UPS-THUNB Uppsala University (Thunberg’s herbarium) viz. Videlicet, namely WIND National Botanical Research Institute, Windhoek Introduction South Africa has been “classical ground” to botanist from all parts of the world ever since the Europeans first settled in the Cape in the sixteenth cen- tury. Swedish botanists are no exception. The Linnean disciple Carl Peter Thunberg were among the earliest explorer (1772–1775) of the flora of “Ca- put Bonae Spei” and together with Carl Gustaf Ekeberg, Michael Grubb, and Anders Sparrman the first important Swedish plant collectors in the area. During the centuries they have had many followers (Glen & Germishuizen, 2010). Thunberg is still known as 'The Father of Cape Botany' after the pub- lication of the first comprehensive treatment of the South African plants, his Flora Capensis (1807–1820) (Glen & Germishuizen, 2010). So why South Africa? The Greater Floristic Region (GCFR) of South Africa (and a small portion of southern Namibia) is unique in having an extraordinary species rich flora (Manning & Goldblatt, 2012; Snijman, 2013). The total number of species and number of endemic species are comparable to the high level of biodiversity in tropical rainforests. The region is divided into two subre- gions: The Extra Cape Subregion (ECR), dominated by the succulent karoo biome (Snijman, 2013), and the Core Cape Subregion (CCR, a.k.a. Cape Floristic Kingdom or Cape Floristic Region) where the famous ericoid Fyn- bos biome dominates (Manning & Goldblatt, 2012). The most species rich family of flowering plants in the area is the Asteraceae (the Sunflower family). Asteraceae (fig. 1) is easily recognized by the typical synflorescence of small florets (tube like disc and/or tongue like ray florets) gathered together in a capitulum and some of the species are well-known to most people, many common as ornamentals. Who has not blown on the spherical gathering of cypselas of a Taraxacum, or picked the ray florets off, one by one, of a Leu- canthemum vulgare, or kneeled in a moment of worship in front of a Tussi- lago farfara on the first sunny day of spring? Names are necessary for communication and not only scientists have use for the Latin, scientific names on plants. There are often regional vernacular names of plants, whereas the scientific names are the same worldwide. Plant systematics deals with classification and taxonomy of plants and tries to identify monophyletic groups (Hennig, 1966; Farris, 1979). To increase knowledge of such groups, systematists study the evolutionary patterns among plants by reconstruction of phylogenetic trees based on derived 13 (apomorphic) character states in terms of morphological and/or molecular data. Figure 1. Asteraceae capitulum and floral parts/korg och blomdelar. The large family Asteraceae is divided into several monophyletic subfami- lies and tribes (Funk & al., 2009). This thesis deals with different issues within one of the tribes, the Arctotideae of the subfamily Cichorioideae. The tribe Arctotideae was recognised for the first time by the great Alexandre Henri Gabriel de Cassini (1816) who studied floral microcharacters in As- teraceae. The Arctotideae was diagnosed by the stylar sweeping hairs having a ring of longer hairs situated below the bifurcation of the style. The tribe contains c. 250 species which are distributed in southern Africa with only one exception, a monotypic genus (genus containing only one single species) found in Australia (Funk & al., 2004). The tribe is still characterized by the typical style morphology, but divided into two subtribes which are more easily recognised: Arctotidinae and Gorteriinae. The plants in Gorteriinae, the group studied for the papers in this thesis, all have strongly connate invo- lucral bracts, unique four-lobed ray florets, alveolate receptacles, and deeply lobed disc floret corollas with reinforced lobe margins (Karis, 2007; Karis & al. 2009). The Gorteriinae comprises eight genera: Gorteria, Hirpicium, Gazania, Berkheya, Cullumia, Cuspidia, Didelta, and Heterorhachis. The three first mentioned,