There's gold in them thar hills! Morphology and molecules delimit species in Xerochrysum (Asteraceae; Gnaphalieae) and reveal many new taxa

Abstract

<p>Golden everlasting paper daisies in the genus <i>Xerochrysum</i> Tzvelev are iconic Australian native plants grown worldwide. The <i>X. bracteatum</i> species complex has been regarded as taxonomically confusing and in need of revision for over 60 years. We applied morphological and molecular analyses to delimit species, detect common ancestry among populations, and identify putative hybrids in the genus <i>Xerochrysum</i> (Asteraceae: Gnaphalieae). Multiple lines of evidence provided strong support for the recognition of new taxa. Here we describe the following 11 new species: <i>X. andrewiae</i> T.L.Collins & J.J.Bruhl, <i>X. berarngutta</i> T.L.Collins & I.Telford, <i>X. copelandii</i> J.J.Bruhl & I.Telford, <i>X. frutescens</i> J.J.Bruhl & I.Telford, <i>X. gudang</i> T.L.Collins & J.J.Bruhl, <i>X. hispidum</i> T.L.Collins & I.Telford, <i>X. macsweeneyorum</i> T.L.Collins, <i>X. murapan</i> T.L.Collins & I.Telford, <i>X. neoanglicum</i> J.J.Bruhl & I.Telford, <i>X. strictum</i> T.L.Collins, and <i>X. wilsonii</i> T.L.Collins, reinstate <i>Helichrysum banksii</i> A.Cunn. ex DC. (as <i>X. banksii</i> (A.Cunn. ex DC.) T.L.Collins & I.Telford), lectotypify <i>X. banksii</i> and <i>X. papillosum</i> (Labill.) R.J.Bayer, and recircumscribe <i>X. bicolor</i> (Lindl.) R.J.Bayer to include <i>X. halmaturorum</i> Paul G.Wilson and some populations of <i>X. bracteatum sens. lat.</i> from mainland South Australia and Victoria. We also provide revised descriptions of all taxa in the genus, their conservation status, a dichotomous key, tables distinguishing closely related taxa and distribution maps.</p>