Revised taxonomy of the Arctotis Annual Clade (Arctotideae, Asteraceae) from Southern Africa: integration of molecular phylogenetic and morphological evidence

Previous phylogenetic analysis of ITS nrDNA sequence data for Arctotidinae species resolved a highly supported clade containing all but one of the showy annual Arctotis species (informally designated the ‘Arctotis Annual Clade’). In the present study, phylogenetic relationships in the Arctotis Annual Clade were investigated by Bayesian inference and maximum parsimony analyses of cpDNA (trnT-trnL-trnF and trnH-psbA) and nrDNA (ITS) sequence data. The cpDNA and nrDNA phylogenies were notably incongruent. Arctotis venusta and a putative unnamed species (‘sp. B’) were highly supported as monophyletic by both datasets. The monophyly of A. leiocarpa was strongly supported by the ITS dataset, whereas the remaining accessions formed a poorly resolved complex (the ‘A. fastuosa complex’). Within the A. fastuosa complex, A. hirsuta was monophyletic with high support in the ITS phylogeny. A statistical parsimony-derived cpDNA haplotype network resolved five broad groups of haplotypes and showed no ...