Phylogenetic relationships of 'Coronidium', 'Xerochrysum' and several neglected Australian species of "Helichrysum" (Asteraceae: Gnaphalieae)

Abstract

A molecular phylogeny of selected Australian native Gnaphalieae (Asteraceae) is inferred from nuclear ribosomal ETS and ITS and chloroplast 'matK-psbA', 'psbA-trnH' and 'ycf6-psbM' sequences to test the reciprocal monophyly of the genera 'Coronidium' and 'Xerochrysum' and to taxonomically place several species currently treated as part of 'Helichrysum'. Ribosomal and chloroplast phylogenies are topologically incongruent, but the latter are poorly resolved and poorly supported. Ribosomal and total evidence data suggest that the 'C. scorpioides' group makes 'Coronidium' in its current circumscription polyphyletic. Even without this species group, remaining 'Coronidium' is inferred to be paraphyletic to 'Xerochrysum'. 'Helichrysum macranthum' and 'H. milligani' are shown to be part of 'Xerochrysum' and formally transferred to that genus. A lectotype is designated for 'H. milliganii'. 'Helichrysum leucopsideum' is shown to be affiliated with 'C. adenophorum' and 'C. waddelliae' while 'H. rutidolepis' is confirmed to be part of the 'C. scorpioides' group. In contrast, the affiliations of 'H. calvertianum', 'H. oligochaetum' and 'H. pumilum' cannot currently be resolved with confidence.