Hibbertia is the largest genus in Dilleniaceae and one of the largest Australian plant genera, with ~350 current and more than 100 known undescribed species in Australia. We present the first published phylogeny based on rigorous sampling of Hibbertia. As part of Genomics for Australian Plants Stage II, 95 Hibbertia species were newly sequenced using Angiosperm353, OzBaits nuclear and OzBaits plastid bait sets, resulting in 402 nuclear and 79 plastid loci that were subsampled to retain the most phylogenetically useful 300 and 60 loci respectively. Nuclear and plastid phylogenies were reconstructed using concatenation and coalescent approaches, and further analysed using Quartet Sampling. We found that Hibbertia and the four subgenera within the genus are robustly supported as monophyletic and recovered 14 major clades, supported in both datasets, within the two largest subgenera (subg. Hemistemma and subg. Hibbertia). However, many relationships between these major clades are unresolved and discordant. Some incongruence was also detected between the plastid and nuclear trees. Discordance was particularly high in the largest eastern Australian clade of subg. Hemistemma. Possible causes of this discordance, and relationships between and within these major clades, are discussed.

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.

The Dicranemataceae was monographed morphotaxonomically by Kraft in 1977, to which the four genera Dicranema Sond., Peltasta J.Agardh., Reptataxis Kraft and Tylotus J.Agardh were attributed. All, save for a species of Tylotus J.Agardh (from east Asia), were endemic to Australia. Additions (in 2006 and 2014 respectively) were the genus Pinnatiphycus N’Yeurt, Payri & P.W.Gabrielson from New Caledonia and Fiji and a new species of Tylotus from Hawaii. General features emphasised by Kraft were similarities of apical and internal structure, zonate tetrasporangia, monoecious gametophytes and placentate cystocarps. The genera did not show uniformity in regard to thallus habits and especially carposporophytes, however, the major differences of which were not accorded any family-level significance. Two later studies, N’Yeurt et al. in 2006 and Kraft et al. in 2014, presented limited molecular data but did not treat the family as a whole or fully resolve relationships between all of the taxa, leaving Kraft’s assumption that the family was monophyletic unchallenged. We address all of the genera, both anatomically and molecularly, and support proposal of two new families, the Peltastaceae and Tylotaceae, in addition to a monogeneric Dicranemataceae. A new genus and species of Peltastaceae, Peltastanomala virantra G.W.Saunders & Kraft, has unique axial and spermatangial anatomies and an unexpected family association with Peltasta. Two additional new genera and species (Chambersius thyrsus G.W.Saunders & Kraft and Huismanophycus marinus G.W.Saunders & Kraft) are even more dissimilar to Peltasta in habit and structure but weakly allied to the Peltastaceae on molecular evidence. Both are therefore regarded as incertae sedis.