Recircumscription of O xera ( L amiaceae: A jugoideae) to include F aradaya based on molecular and anatomical data

Oxera is a genus of c. 20 species from N ew C aledonia and V anuatu. Its phylogenetic placement in L amiaceae ( A jugoideae) remained uncertain until studies showed close affinities with the large pantropical genus C lerodendrum , the I ndo‐ P acific F aradaya (three species) and the monotypic H osea from B orneo. We reassessed the relationships of O xera with these genera by building a phylogenetic framework based on six plastid and six nuclear loci and on a sampling including 30 ingroup species. The results show that C lerodendrum and its closely related genera are sister to the alliance encompassing F aradaya , H osea and O xera . Hosea is sister to all species of O xera and F aradaya . F aradaya is recovered as polyphyletic as it is partly nested within O xera . Extensive morphological variability is observed in O xera . However, O xera also shares strong similarities with the three F aradaya species. Polyphyletic F aradaya is therefore placed in synonymy with O xera and we propose three new combinations: O. amicorum , O. lehuntei and O. splendida . A unique synapomorphy supports this new circumscription of O xera : the petiole vascularization consisting of several small vascular bundles arranged in an interrupted full circle (vs. a large bundle in a half circle in other ajugoids). O xera thus comprises c. 37 species, with a diversity centre in N ew C aledonia. Biogeographical processes, plastid paralogy and vascularization shift are discussed. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society , 2015, 179 , 693–711.