Senna section Chamaefistula series Bacillares (Benth.) H.S.Irwin & Barneby comprises ~50 Neotropical legume species occurring in both tropical and subtropical areas. Approximately 25 of those species occur in Brazil, with nine being endemic. This work provides a taxonomic study of Senna section Chamaefistula series Bacillares in the Atlantic Forest north of the São Francisco River in north-eastern Brazil, which is considered a global hotspot for biodiversity, contributing to understanding their taxonomy, diversity and distribution, as well as analysing morphological variations that have led to identification errors in the past. Fieldwork was conducted to make observations and collect fresh material; specimens from national and international herbaria were also examined. Senna section Chamaefistula series Bacillares is represented in the study area by nine species (of which four are endemic to Brazil), including S. pluribracteata F.S.Souto & R.T.Queiroz, a species recently described for the area. All species of the series known from the study area are described and illustrated and a key is provided. Additionally, four names were typified, with two lectotypes and two neotypes being designated here. The results have reinforced the importance of conducting floristic inventories for documenting new species and new occurrences.

A taxonomic revision of the Pultenaea setulosa species complex (Fabaceae, tribe Mirbelieae) is presented. Prior to this study, P. setulosa Benth. was broadly circumscribed as a single, morphologically variable species. Here, we present evidence supporting the recognition of 18 species, 14 of which are new to science. Pultenaea setulosa is recircumscribed as a morphologically uniform taxon endemic to the Marlborough region in south-east Queensland. We reinstate Pultenaea boormanii H.B.Will., Pultenaea campbellii Maiden & Betche and Pultenaea lapidosa Corrick from synonymy of P. setulosa and describe an additional 14 new species: Pultenaea acanthocalyx R.L.Barrett & Clugston, Pultenaea corrickiae R.L.Barrett, Orme & Clugston, Pultenaea estelleae R.L.Barrett & Clugston, Pultenaea farmeriana R.L.Barrett, Orme & P.H.Weston, Pultenaea hoskingii R.L.Barrett & Clugston, Pultenaea imminuta R.L.Barrett & S.F.McCune, Pultenaea murrayi R.L.Barrett, Pultenaea palssoniae R.L.Barrett & Clugston, Pultenaea praetermissa R.L.Barrett & Albr., Pultenaea purdieae R.L.Barrett & Clugston, Pultenaea renneri R.L.Barrett & Clugston, Pultenaea venusta R.L.Barrett & Orme, Pultenaea westonii R.L.Barrett & Clugston and Pultenaea woolcockiorum R.L.Barrett & Clugston. Sixteen of these species are endemic to New South Wales, one to Queensland and one to Victoria. All taxa are described and illustrated, and habitats and conservation status are discussed. Two additional related species, Pultenaea procumbens A.Cunn. and P. setigera A.Cunn. ex Benth. are recircumscribed. Pultenaea setigera is reinstated here, known from the type collection made in 1822 and is possibly extinct. Lectotypes are selected for the names Pultenaea boormanii, P. campbellii, P. procumbens, P. setigera and P. setulosa.

The South American central Andes have a great richness of Asteraceae, where the genus Stevia (Eupatorieae, Piqueriinae) is also especially diverse. The taxonomy of Stevia species in the southern part of the central Andes pose a challenge because of the unclear delimitation among the species and overlap of morphological characters. Two species complexes were identified for the region comprising north Argentina and southern Bolivia. In this study, our objectives were to employ morphometric analyses to assess the delimitation of taxa within the Stevia alpina Griseb. and Stevia chamaedrys Griseb. complexes. We aimed to identify informative morphological characters and gain insight into the identity of species in each group. To accomplish this, we utilised cluster analysis, principal-component analysis, non-metric multidimensional scaling and univariate analyses to evaluate 37 morphological traits. In total, 200 specimens were examined, covering the entire geographic distribution of each species complex. We found support for the recognition of nine species: Stevia alpina, S. breviaristata Hook. & Arn., S. chamaedrys, S. mandonii Sch.Bip., S. mercedensis Hieron., S. minor Griseb., S. potrerensis Hieron., S. procumbens Hieron. and S. vaga Griseb. A new combination and status is proposed for S. tarijensis Hieron., incorporating it as a variety of S. mandonii, and S. centinelae Cabrera and S. crassicephala Cabrera are merged as synonyms under the name S. alpina. Two neotypes are designated for the names S. mercedensis and S. potrerensis.

Resolution of systematic associations and species boundaries is vital for developing conservation priorities for threatened taxa. A complex of Fontainea (Euphorbiaceae) populations, endemic to rainforest communities in central-eastern Australia, comprises several taxonomically challenging species. Fontainea oraria is Critically Endangered, with only one natural population of 10 mature individuals, with the closely related species F. australis being listed as Vulnerable. A recently discovered Fontainea population (currently nominated as F. sp. Coffs Harbour) with taxonomic similarities to F. oraria has been provisionally listed as Critically Endangered, with fewer than 40 individuals. This study employed an integrative approach, combining genetic data and morphometrics to determine species boundaries for three threatened Fontainea population groups as a model system for an integrative approach to delimiting cryptic species. Although our results suggest the potential subdivision of the population groups into three taxa, caution is warranted because this hypothesis remains inconclusive. Taxonomic challenges demand a careful approach, acknowledging the possibility of alternative interpretations. Contrary to supporting distinct species, our morphological and genetic data may also be interpreted as indicative of a single species with geographic variation, a phenomenon observed in genetically linked populations experiencing isolation by distance. Overall, we highlight the need for further research to establish species limits to guide conservation actions.

Derris Lour. and Brachypterum (Wight & Arn.) Benth. (Leguminosae subfamily Papilionoideae) in Australia are revised on the basis of examination of fresh, dried and spirit-preserved specimens and phylogenetic analysis of plastid matK and nuclear internal transcribed spacer (ITS) sequence data. Three species of Derris and four species of Brachypterum are recognised as occurring in Australia. Two new Brachypterum species, namely Brachypterum nitidum W.E.Cooper and Brachypterum opacum W.E.Cooper, are described and illustrated. Notes on habitat, distribution and an identification key are presented for all species of both genera that occur in Australia.