Data_and_scripts

Tackling the complicated infrafamilial classification of the economically important Oleaceae requires a piecemeal approach that addresses generic circumscriptions. Here, focusing on the distinct clade formed by the generic complex <i>Nestegis</i>, <i>Notelaea</i>, <i>Osmanthus</i>, <i>Phillyrea</i>, and <i>Picconia</i> within the subtribe Oleinae, we aim to elucidate their boundaries and relationships and to evaluate their biogeographic history in light of their peculiar disjunct distribution in Macaronesia, the Mediterranean Region, and the Pacific. Based on phylogenomic data from plastid and nuclear DNA and extensive sampling, the results show six subclades within this generic complex, which are also geographic segregates found in Australia (<i>Notelaea</i>), Hawaiian Islands (<i>Nestegis sandwicensis</i>), Macaronesia (<i>Picconia</i>), Mediterranean Region (<i>Phillyrea</i>), New Caledonia (<i>Osmanthus</i> section <i>Notosmanthus</i>), and New Zealand (<i>Nestegis s.s.</i>). Accounting for broad morphological overlaps within this clade, we recognize three genera (<i>Phillyrea</i>, <i>Picconia</i>, and <i>Notelaea s.l.</i>), subsuming all Pacific taxa under <i>Notelaea s.l.</i> Molecular dating and biogeographic analyses indicate that this clade originated in Eurasia during the Early Miocene (ca. 23 Mya) and that dispersal only can be favored to explain its global disjunct distribution. Although the colonization route to the Hawaiian Islands is unclear, island-hopping and local extinction seem to be the hallmark of the evolutionary history of this group.