Target capture sequencing clarifies key relationships in the <i>Eriostemon</i> group (Rutaceae: Zanthoxyloideae) and supports a reclassification of <i>Philotheca</i>, including the recognition of two new genera

Abstract The Eriostemon group (Rutaceae) is a clade of 16 genera and ~ 209 species endemic to Australia, New Zealand and New Caledonia. Recent efforts to address taxonomic and phylogenetic uncertainty in the group using plastome and nuclear ribosomal DNA sequences have made some progress but have also highlighted problematic areas that require further research. In particular, the current circumscription of Philotheca is known to be non‐monophyletic, but unclear phylogenetic relationships have prevented reclassification of the group. We generated target capture data using the Angiosperms353 universal bait kit and conducted phylogenetic analyses on the Eriostemon group with the aims of resolving uncertain backbone relationships and clarifying the relationships of Philotheca . Our results uncovered extensive cytonuclear discordance in the group, with conflict between our nuclear DNA phylogenies and previous plastome DNA phylogenies observed in several key areas of the tree. Despite this, the positions of the polyphyletic lineages of Philotheca were consistent enough across nuclear DNA and plastome DNA phylogenies to enable a confident reclassification of the genus, which is presented herein. Two sections of Philotheca , P. sect. Corynonema and P. sect. Erionema , are raised to generic rank under the names Corynonema and Erioseira , respectively. Philotheca sect. Cyanochlamys , is transferred into the genus Muiriantha . The type section of Philotheca is retained and becomes the entirety of that genus. Appropriate nomenclatural changes are made to transfer all currently recognised species and subspecies to their respective genera under this new classification.