Morphological, phytochemical and molecular analyses define species limits in Eucalyptus magnificata (Myrtaceae) and lead to the discovery of a new rare species

Abstract

<I>Eucalyptus magnificata</I> L.A.S.Johnson & K.D.Hill is an endangered species endemic to the New England Tablelands Bioregion of eastern Australia, with taxonomic conflict regarding its recognition. Analyses of morphology, phytochemistry and genomic DNA were used to test species limits of <I>E. magnificata</I>. Morphometric and phytochemical phenetic analyses found distinct differences among <I>E. magnificata, E. baueriana</I> and a putative entity recognised during field collection, i.e. <I>E</I>. sp. Dalveen. Another putative entity, <I>E</I>. sp. Oxley, was morphologically and phytochemically intermediate between <I>E. magnificata</I> and <I>E. conica</I>. Phenetic analysis of single-nucleotide polymorphism (SNP) data supported the results from morphological and phytochemical analyses. The original circumscription of <I>E. magnificata</I>, as distinct from <I>E. baueriana</I>, was strongly corroborated. <I>Eucalyptus magnificata</I> was found to be restricted in distribution to the Macleay Gorges area south-east of Armidale. Multiple lines of evidence provided strong support for the recognition of <I>E</I>. sp. Dalveen as a separately evolving entity at a species level, here described as <I>Eucalyptus dalveenica</I> T.L.Collins, R.L.Andrew & J.J.Bruhl. A full description of the new species, a table distinguishing <I>E. dalveenica</I> from closely related taxa, and an identification key are provided. Distribution, habitat and conservation status are discussed.