ETS sequences support the monophyly of the eucalypt genus Corymbia (Myrtaceae)

Abstract

AbstractThe generic classification of the eucalypts, especially recognition of the genus Corymbia, has been controversial. The phylogeny of Corymbia and related eucalypt groups was investigated using nuclear ETS sequences, and combined ETS and ITS sequences. Both the ETS and combined datasets support the monophyly of Corymbia. Three major eucalypt clades are confirmed: Corymbia + Angophora; Eucalyptus s.s.; and the Eucalyptopsis group. Within Corymbia, relationships are broadly consistent with phylogenies based on morphological and anatomical characters; sections Ochraria, Blakearia, and Politaria are all supported as monophyletic; sect. Rufaria is monophyletic with the inclusion of the monotypic sect. Apteria. Within Eucalyptus s.s., relationships are generally consistent with those shown by previous molecular studies. Within the Eucalyptopsis group, Allosyncarpia is sister to the clade Stockwellia + Eucalyptopsis. Relationships between the major eucalypt clades are equivocal, but combined analysis of ETS and ITS data shows Corymbia + Angophora as sister to Eucalyptus—the rainforest taxa of the Eucalyptopsis group being outside this clade. Patterns of relationship and distribution are consistent with differentiation of major lineages of Corymbia prior to the isolation of taxa (now relictual) in eastern and south‐western Australia, arguably before the mid‐Miocene.