Philyrophyllum (Asteraceae) transferred from Gnaphalieae to Athroismeae based on phylogenetic analysis of nuclear and plastid DNA sequence data

The small southern African genus Philyrophyllum (Asteraceae) has traditionally been placed amongst t he basal lineages of tribe Gnaphalieae, close to the Namibian-centred genus Pentatrichia. However, a recent plastid phylogeny placed Philyrophyllum distant from Pentatrichia within the Gnaphalieae crown radiation, a finding that is strongly contradicted by a suite of morphological synapormorphies that are otherwise unvarying within the crown radiation. In the present study, two linked nuclear loci (ITS, ETS) and one plastid region (trnL-trnF) are sequenced to determine the phylogenetic position of Philyrophyllum, with the addition of available plastid psbA-trnH spacer and ndhF sequences for outgroup taxa. Maximum likelihood bootstrap and Bayesian analysis is used to assess support for phylogenetic relationships. Individual plastid and nuclear, as well as combined data, strongly support a close relationship between Philyrophyllum and the African-centred, morphologically diverse genus Anisopappus, currently placed in subtribe Anisopappinae of the anomalous tribal assemblage Athroismeae. Athroismeae is the sister group of Feddeeae and the "Heliantheae tribal alliance", a large mainly northern hemisphere grouping that is phylogenetically distant from Gnaphalieae.