Systematics and phylogenetics of the Blepharispermum group (Asteraceae - Heliantheae)

Abstract: This thesis treats the Blepharispermum group which comprises the three genera Athroisma DC., Blepharispermum Wight ex DC., and Leucoblepharis Arnott. The systematic position of the group within the Asteraceae is discussed, and a transfer is proposed from the tribe Inuleae, where it was placed earlier, to the Heliantheae. The subtribal position within the Heliantheae is also discussed. A dadisric analysis of all species shows that the genera are monophyletic. The genus Leucoblepharis is reinstated for the sister species of Blepharispermum. Each genus is treated in more detail and nomenclature, taxonomy, morphology, distribution maps, and phylogenetic analyses are presented. In Blepharispermum, 15 species are accepted of which two are new, and in Athroisma 12 species are accepted of which four are new. In Athroisma, where intermediate collections abound, the correlation of character patterns with geographical distributions is investigated. Introgressive hybridisation is hypothesised to account for the presence of four intermediate ”groups” of specimens. The relationships, taxonomic status, and origin of those groups are discussed.