More links in the daisy chain: morphology and molecules delimit two new species in Coronidium and two in Leucozoma (Asteraceae; Gnaphalieae)

Taxonomic uncertainty in Coronidium has existed since its original circumscription. Recent molecular phylogenetic analyses inferred Coronidium to be non-monophyletic and composed of four distinct clades, leading to the erection of Leucozoma and the confirmation that C. scorpioides (Labill.) Paul G.Wilson and related species are more closely related to other Australian Gnaphalieae. The present study focused on the delimitation of those species inferred to be part of Coronidium, Leucozoma and the closely related Helichrysum leucopsideum DC. We gathered DArTseq single-nucleotide polymorphism data and tested species limits by examining genotypic differences, ancestry, and morphological characters observed on herbarium specimens and living collections. Results support the recognition of four new narrowly endemic species, namely, C. batianoffii T.L.Collins & I.Telford, C. bruhlii T.L.Collins, L. alexandri T.L.Collins and L. wollumbin T.L.Collins. Results indicated that the narrow endemic C. fulvidum Paul G.Wilson is a variable hybrid between C. newcastlianum (Domin) Paul G.Wilson and C. rupicola (DC.) Paul G. Wilson, and subspecies of C. oxylepis (F.Muell.) Paul G.Wilson to be a polymorphic aggregate or ochlospecies, the subject of ongoing study. We lectotypify H. elatum A.Cunn ex DC. and Helipterum glutinosum Hook. and provide revised descriptions of all taxa in the genera, their conservation status, a dichotomous key, tables distinguishing closely related taxa and distribution maps.