Phylogenomic analysis of the generic limits of Chrysocephalum.

Shelley Rowntree (University of New England); Alexander Schmidt-Lebuhn (CSIRO, Centre for Australian National Biodiversity Research); Jeremy Bruhl (University of New England); Ian Telford (University of New England); Rose Andrew (University of New England).

Chrysocephalum Walp. is a medium-sized genus in the Waitzia clade of the Australian Gnaphalieae (Asteraceae), comprising nine currently recognised species and two phrase-named species. Detailed relationships within the clades of the Gnaphalieae remain largely unresolved, and generic concepts are often based on a small number of morphological characters traditionally considered important. In a recent revision of the C. apiculatum and C. semipapposum complexes (Wilson 2016), 34 subspecies were named based on morphological characters, with a high level of complexity making distinction difficult among them. Towards my Ph.D. project, I have inferred a molecular phylogeny of selected Australian native Gnaphalieae (Asteraceae) using target capture sequences to test the monophyly of the Chrysocephalum. A group of three species formed the “core” Chrysocephalum clade, C. apiculatum (type species), C. semipapposum and C. vitellinum. Arid zone species formed separate clades. Further studies are underway to identify morphological and anatomical synapomorphies for clades and to resolve species limits and species-level relationships with molecular and morphological analyses.