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Variation in breeding systems between species of the same taxonomic group complicates the consistent application of species concepts, and perhaps even the logically consistent circumscription of species. Several genera of arid-zone ephemerals in the Angianthus clade (Asteraceae: Gnaphalieae: Gnaphaliinae) contain both outcrossing and non-outcrossing species. The latter are recognised by producing an order of magnitude fewer pollen grains per anther and an often reduced number of corolla lobes, and they are frequently more widespread than are the former. In its current taxonomy, the genus Pogonolepis comprises an otherwise morphologically indistinguishable pair of one outcrossing and one non-outcrossing species. I generated sequence capture data to test the genetic segregation of P. stricta and P. muelleriana and the utility of sequence capture data for species circumscription and diagnostics. Phylogenetic analysis showed the two species to form two specimen clades, supporting the current taxonomy. Contrary to expectations, non-outcrossing P. muelleriana exhibited lower gene concordance, in line with values expected from recombination, as well as higher heterozygosity than its outcrossing sister species. More research on the breeding system and population structure of the two species may be required to explain these results.

Golden everlasting paper daisies in the genus Xerochrysum Tzvelev are iconic Australian native plants grown worldwide. The X. bracteatum 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 Xerochrysum (Asteraceae: Gnaphalieae). Multiple lines of evidence provided strong support for the recognition of new taxa. Here we describe the following 11 new species: X. andrewiae T.L.Collins & J.J.Bruhl, X. berarngutta T.L.Collins & I.Telford, X. copelandii J.J.Bruhl & I.Telford, X. frutescens J.J.Bruhl & I.Telford, X. gudang T.L.Collins & J.J.Bruhl, X. hispidum T.L.Collins & I.Telford, X. macsweeneyorum T.L.Collins, X. murapan T.L.Collins & I.Telford, X. neoanglicum J.J.Bruhl & I.Telford, X. strictum T.L.Collins, and X. wilsonii T.L.Collins, reinstate Helichrysum banksii A.Cunn. ex DC. (as X. banksii (A.Cunn. ex DC.) T.L.Collins & I.Telford), lectotypify X. banksii and X. papillosum (Labill.) R.J.Bayer, and recircumscribe X. bicolor (Lindl.) R.J.Bayer to include X. halmaturorum Paul G.Wilson and some populations of X. bracteatum sens. lat. 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.

Variation in breeding systems between species of the same taxonomic group complicates the consistent application of species concepts, and perhaps even the logically consistent circumscription of species. Several genera of arid-zone ephemerals in the Angianthus clade (Asteraceae: Gnaphalieae: Gnaphaliinae) contain both outcrossing and non-outcrossing species. The latter are recognised by producing an order of magnitude fewer pollen grains per anther and an often reduced number of corolla lobes, and they are frequently more widespread than are the former. In its current taxonomy, the genus Pogonolepis comprises an otherwise morphologically indistinguishable pair of one outcrossing and one non-outcrossing species. I generated sequence capture data to test the genetic segregation of P. stricta and P. muelleriana and the utility of sequence capture data for species circumscription and diagnostics. Phylogenetic analysis showed the two species to form two specimen clades, supporting the current taxonomy. Contrary to expectations, non-outcrossing P. muelleriana exhibited lower gene concordance, in line with values expected from recombination, as well as higher heterozygosity than its outcrossing sister species. More research on the breeding system and population structure of the two species may be required to explain these results.

Present patterns of diversity in the Australian flora have been shaped by increasing seasonality since the Eocene, and by pronounced aridification in the past 3 million years. Arid-zone plants are commonly hypothesised to be the products of radiations of ancestrally temperate or coastal lineages, as in the case of the everlasting paper daisy tribe Gnaphalieae (Asteraceae). However, these inferences are often based on higher-level phylogenies, whereas evolutionary processes in the Australian Gnaphalieae have rarely been studied at the species level. Here, we reconstructed the phylogeny and biogeographic history of the small, but ecologically diverse, paper daisy genus Leucochrysum, to examine recent habitat shifts and character changes, at the same time exploring the feasibility of using amplicon sequencing of low-copy nuclear gene regions to resolve phylogenetic relationships in Australian Gnaphalieae. On the balance of evidence, outgroup comparison and ancestral-area reconstruction support an ancestral range in the arid zone with subsequent diversification towards the south-east, demonstrating a complex evolutionary history with a re-colonisation of temperate areas. Low amplification success rates suggest that methods other than amplicon sequencing of currently available primers will be more promising for molecular phylogenetic work at a larger scale.

The Australasian clade of Gnaphalieae (Asteraceae) is an ecologically diverse group of species whose generic limits and phylogenetic relationships are still partly unresolved. Previous studies including hybridisation trials, morphological characterisation and preliminary phylogenetic analyses within the Gnaphalieae have suggested that two genera, namely, Waitzia and Leucochrysum, require further investigation into their generic boundaries. To explore the phylogenetic relationships of both genera, the present study used a combination of morphological and molecular approaches. The character traits of herbarium specimens from 14 species and six infraspecific taxa of Waitzia, Leucochrysum and Anemocarpa were examined. Chloroplast (psbA–trnH) and nuclear ribosomal ITS and ETS sequences were generated for phylogenetic analysis. Our findings support Waitzia in its current circumscription as a monophyletic group, whereas Leucochrysum was found to be polyphyletic. Leucochrysum fitzgibbonii was found to be the sister group of Waitzia and shares characters of the involucral bracts, indumentum and growth habit with that genus. The species is formally transferred to the genus Waitzia as W. fitzgibbonii.

The first comprehensive quantitative study of morphological characters in all Australian species of the billy button genus Craspedia (Asteraceae, Gnaphalieae) is presented. Homogeneity analysis and pair-wise reclassification tests are used to test species circumscriptions under the genotypic-cluster concept. Although most species are supported, C. aurantia and C. jamesii do not form separate morphological clusters, and C. jamesii is reduced to a variety of C. aurantia. Although our results indicated that C. variabilis may be synonymous with C. glauca, we reserve judgment because of the small number of specimens of the latter species included in the present study. Other species were found to be less problematic; however, additional and more detailed studies will be needed to clarify the circumscription of various species with woolly leaf indumentum, in particular C. canens, C. coolaminica and C. macrocephala. A synopsis of all Australian species of Craspedia is presented, together with a preliminary key.