SUMMARY A synopsis of the southern African members of the genera Dicoma Cass. and Macledium Cass. (family Asteraceae, subfamily Cichorioidiae, tribe Mutiseae, subtribe Gochnatiinae) is presented. The most recent monograph of Dicoma was done by Wilson (1923). It included 34 species, of which 17 are southern African, The southern African species were last treated by Harvey (1865). Traditionally Dicoma included 50 to 65 species, of which 23 occur in southern Africa. Ortiz (2001) reinstated the genus Macledium Cass., which was first described by Cassini (1825), following a phylogenetic study of Dicoma and related genera (Ortiz, 2000). The species previously belonging to sections Macledium and Pterocoma of the genus Dicoma have been transferred to the genus Macledium by Ortiz (2001). In this study, characters relating to morphology of the involucral bracts, disc floret cuticle ornamentation, type of pappus and the type of achenes are used to distinguish the two genera. Differences were found between the grassland species and Cape species of Macledium. Type of florets in the capitulum and pappus morphology are used to distinguish sections within Dicoma sensu stricto. Characters such as habit, leaf morphology, shape and size of the capitulum, involucral bracts vestiture and details of the pappus could be reliably used to distinguish species. i The genus Dicoma now consists of about 35 species, of which16 species and two subspecies occur in southern Africa. Four informal groups of D. anomala subsp. anomala, two of D. anomala subsp. gerrardii as well as two of D. montana are recognized to accommodate infraspecific variation. Macledium comprises about 20 species, of which seven species, three subspecies and three varieties occurr in this region. M. spinosum is divided into two informal forms and a new combination, Macledium zeyheri subsp. zeyheri var. thyrsiflorum, is made. In view of the above, a comprehensive taxonomic revision of all the southern African taxa was done. Morphological and anatomical data were used to investigate relationships among the species of Dicoma sensu stricto, using the genus Macledium as the sister group. A phylogenetic analysis of Macledium was also done to investigate relationships between the grassland species and the Cape species. The taxonomic treatment includes the nomenclature, synonymy, diagnostic characters, uses, common names (where possible) and geographical distribution for all southern African taxa belonging to the two genera. Keys to the genera, sections, species and subspecies are provided and the diagnostic characters of the two genera are illustrated. ii OPSOMMING ’n Oorsig word gegee van die Suider-Afrikaanse taksons van die genusse Dicoma Cass. en Macledium Cass. (familie Asteraceae, subfamilie Cichorioidiae, tribus Mutiseae, subtribus Gochnatiinae). Die mees onlangse monografie oor Dicoma is deur Wilson (1923) gedoen. Dit het 34 spesies ingesluit, 17 daarvan van Suider-Afrika. Die Suider-Afrikaanse spesies is laas deur Harvey (1865) behandel. Dicoma het tradisioneel 50 tot 65 spesies ingesluit, waarvan 23 in Suider-Afrika voorkom. Ná ’n filogenetiese ondersoek van Dicoma en verwante genusse (Ortiz, 2000), het Ortiz (2001) die genus Macledium Cass., wat deur Cassini (1825) beskryf is, weer ingestel. Die spesies wat voorheen aan die seksies Macledium en Pterocoma van die genus Dicoma behoort het, is na die genus Macledium oorgedra deur Ortiz (2001). In hierdie ondersoek word kenmerke wat betrekking het op die morfologie van die omwindselskutblare, ornamentasie van die buisblomkutikulum, tipe pappus en die tipe agene gebruik om die twee genusse te onderskei. By Maclidium is verskille is tussen die grasveldspesies en Kaapse spesies gevind. Die tipe blommetjies in die hofie en die morfologie van die pappus word gebruik om tussen seksies in Dicoma sensu stricto te onderskei. Kenmerke soos groeiwyse, blaarmorfologie, vorm en grootte van die hofie, iii bedekking van die omwindselskutblare en besonderhede van die pappus kan betroubaar gebruik word om spesies te onderskei. Die genus Dicoma bestaan nou uit sowat 35 spesies, waarvan 16 spesies en twee subspesies in Suider−Afrika voorkom. Vier informele groepe van D. anomala subsp. anomala, twee van D. anomala subsp. gerrardii asook twee van D. montana word erken om vir infraspesifieke diversiteit voorsiening te maak. Macledium bestaan uit 20 spesies, waarvan sewe spesies, drie subspesies en drie variëteite in hierdie gebied voorkom. M. spinosum word in twee informele vorms verdeel en ’n nuwe kombinasie, Macledium zeyheri subsp. zeyheri var. thyrsiflorum, word gemaak. In die lig van bostaande is ’n omvattende taksonomiese hersiening van al die Suider- Afrikaanse taksons gedoen. Morfologiese en anatomiese data is gebruik om verwantskappe tussen die spesies van Dicoma sensu stricto te ondersoek, met Macledium as die sustergroep. ’n Filogenetiese ontleding van Macledium is ook gedoen om verwantskappe tussen die grasveld- en Kaapse spesies te ondersoek. Die taksonomiese behandeling sluit die nomenklatuur, sinonimie, diagnostiese kenmerke, gebruike, volksname (waar moontlik) en geografiese verspreiding van alle Suider-Afrikaanse taksons van die twee genusse in. Sleutels tot die genusse, seksies, spesies en subspesies word verskaf en die diagnostiese kenmerke van die twee genusse word geïllustreer. iv 1 2 3 5 6 7 4 9 10 8 11 13 12 1 = Namibia 2 = Botswana 3 = Northern Province 4 = North West 5 = Gauteng 6 = Mpumalanga 7 = Swaziland 8 = Northern Cape 9 = Free State 10 = Lesotho 11 = KwaZulu-Natal 12 = Western Cape 13 = Eastern Cape Figure 1 Map of southern Africa showing the areas included in the Flora of southern African region (the area also covered by this study). v.