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.

A molecular phylogeny, morphological descriptions, species lists and a key to the sections of Croton L. (Euphorbiaceae) recognised for Australia are presented. The molecular phylogenetic results supported the recognition of six sections, to account for the 29 native Australian species. The monophyly of each of these sections was highly supported in the Bayesian and maximum-likelihood analyses of nuclear ITS and plastid trnL–F DNA sequences, whereas their relationships to each other and to other groups were less well resolved. Croton may represent one, two or three separate arrivals to Australia, with support for hypotheses of subsequent dispersals from Australia to Pacific islands and to Asia. Croton sections Argyrati, Arnhemici, Caudati, Dockrilliorum and Insulares are newly described. Croton section Gymnocroton Baill., previously placed in synonymy, is again recognised. Croton armstrongii S.Moore is excluded from the Australian flora.

A rare, new tetraploid Atriplex, restricted to two populations ∼30 km apart in arid Western Australia, is supported as a distinct species by morphological and molecular evidence. Genetic analyses using amplified fragment length polymorphisms (AFLPs) showed significant genetic divergence between the two populations. In contrast, an ordination based on elliptic Fourier descriptors for leaf and bracteole shape did not identify any consistent morphological differentiation. Although the level of genetic differentiation is similar to that previously reported between subspecies in other Atriplex, the populations of the new taxon are described herein as A. yeelirrie K.A.Sheph. & K.R.Thiele, without taxonomic recognition at the intraspecific level. We outline our reasoning for this decision and discuss the implications for appropriate conservation management of the species, structured into two genetically distinct populations.

Many species of Stephania Lour. are used traditionally in South-east Asia as medicinal plants. Understanding and predicting their therapeutic properties could be improved, provided that the evolutionary relationships among lineages are clarified. We present the first molecular phylogeny of the genus Stephania, focusing on the species occurring in China on the basis of nuclear (internal transcribed spacer, ITS) and chloroplast (trnL–F) markers sequenced from 29 species of Stephania. Our results showed that S. subgenus Stephania and S. subgenus Tuberiphania are not monophyletic, owing to the phylogenetic placement of a single species (S. mashanica). The relationships with the third subgenus, S. subgenus Botryodiscia, are not resolved. None of the sections in our analyses is monophyletic. Our study calls for further phylogenetic investigations including more accessions from the whole distribution area of the genus. A taxonomic revision of the genus Stephania, which would reassess the appropriateness of the macromorphological characters used so far to distinguish among subgenera (e.g. flower merism, size and aspect of the rootstock and main root), and sections (e.g. inflorescence morphology, sessiliflorous or not), is much needed.

Recent studies have transferred several species previously attributed to the fern genus Oenotrichia to other genera, and even out of the Dennstaedtiaceae to other families. However, the relationship of the type species, O. maxima from New Caledonia, has not previously been investigated using DNA sequences. With phylogenetic analyses of chloroplast DNA sequences, we verify the placement of Oenotrichia within the Dennstaedtiaceae. Moreover, O. maxima actually nests along with Leptolepia in a clade of Dennstaedtia. Dennstaedtia itself is non-monophyletic, with a second clade being more closely related to Microlepia. We outline what is required to resolve the generic taxonomy of this group. We also find that samples attributed to Saccoloma are polyphyletic, with some falling inside the Dennstaedtiaceae and others outside.