Eucalypt phylogeny — molecules and morphology

Abstract

Molecular (5S rDNA spacer and chloroplast DNA RnPs) and morphological data sets are informative at different levels of the eucalypt clade. They allow separate analysis of major subclades, the results of which, when combined, give a single, phylogenetic tree for Angophora Cav. and Eucalyptus L'Hér. For taxonomic revision, the tree supports the recognition of bloodwood eucalypts as monophyletic, but shows that informal subgenus Corymbia Pryor & Johnson is paraphyletic. The tree supports recognition of three major clades within the non-bloodwood eucalypts ('eudesmids', 'symphyomyrts' and 'monocalypts') and suggests relationships for taxa within each of these. Ovule and seed characters proved to be most informative in the morphological data set. The phylogenetic hypothesis suggests interpretations for homoplasious morphological characters, including parallel evolution of sepaline and petaline opercula (and associated stemonophore) and types of conflorescence.