Halgania (Ehretiaceae, Boraginales) comprises ∼20 species of ericoid shrubs endemic to Australia. The current taxonomic concepts based on morphology are confusing and are sometimes based on misidentification or lack of information about the type material. We describe the morphological diversity and infer relationships using molecular phylogenetics. The five petals in all Halgania species are blue to violet (rarely white). The yellow or yellow-purple anthers are connected into a cone surrounding the single style. Differences among the species are mainly found in the indumentum of the plants, the leaf margin (i.e. degree of serration), the sepals (being either of equal or of unequal size) and the length of the beak-like anther appendages. A phylogenetic tree mainly based on ITS sequences retrieves three highly supported groups. The H. andromedifolia clade uniquely has sepals of unequal size, and the H. anagalloides clade exhibits dolabriform trichomes. The remaining taxa (constituting the H. littoralis clade) lack such diagnostic morphological traits, but are reliably retrieved as sister group to the H. anagalloides clade. As a first step towards the taxonomic revision of Halgania, we have compiled a nomenclatural list of all validly published names (at the species level and below), provide information about herbarium deposition of original material and discuss the current use of the names.

Pleioluma (Baill.) Baehni (Sapotaceae) circumscribes some 40 medium-sized trees and shrubs, many gynodioecious, in Australia, Malesia and New Caledonia. Systematics of the group is unclear and delimitations of species are notoriously difficult. We explore species boundaries in New Caledonia by multiple accessions of ‘species’, molecules and morphology in a Bayesian framework. The molecular phylogenetic signal is weak, but morphology provides enough information to support groups, species and recognition of one cryptic species. Pleioluma is then revised for New Caledonia, a genus distinguished by areolate higher leaf venation, sepals being pubescent on both surfaces, stamens inserted in or below the middle of the corolla tube, presence of staminodes, foliaceous cotyledons and endosperm. Seventeen endemic species are recognised with descriptions, recognition notes, distributions, etymologies and conservation assessments. Six species are described as new, of which four are assigned IUCN preliminary status as Critically Endangered and in urgent need of protection (Pleioluma acutifolia Swenson & Munzinger, P. belepensis Swenson & Munzinger, P. butinii Swenson & Munzinger and P. tchingouensis Swenson & Munzinger). The new species, P. dioica Swenson & Munzinger and P. tenuipedicellata Swenson & Munzinger are respectively assessed as Data Deficient and Vulnerable. The micro-endemic species P. vieillardii (Baill.) Swenson & Munzinger, confined to the Koniambo massif, is also critically endangered and needs urgent conservation management.

Proteaceae subfamily Persoonioideae, as presently circumscribed, consists of the monogeneric tribe Placospermeae (Placospermum) and the tribe Persoonieae. The latter comprises the diverse genus Persoonia and monospecific genera found in New Zealand (Toronia), New Caledonia (Garnieria) and south-western Western Australia (Acidonia). Persoonia has 101 species distributed across Australia and has been classified into 11 informal groups. Using data derived from plastid DNA (trnL–trnF region), nuclear rDNA (ITS) and morphological characters, we constructed a phylogeny of Persoonioideae and compared the results to the existing classification. Bayesian and parsimony analyses indicated that Persoonia, as currently defined, is non-monophyletic. The molecular data and combined molecular and morphological data place Toronia in a moderately well supported clade with the monophyletic Rufiflora group of Persoonia from Western Australia. This clade is sister to Acidonia, Garnieria and the remaining Persoonia species. Of the other informal groups in Persoonia, the Teretifolia, Quinquenervis, Laurina, Arborea, Graminea and Chapmaniana groups are supported as monophyletic. The Lanceolata group can be re-circumscribed to be monophyletic by the addition of P. elliptica R.Br. (Longifolia group) and the Dillwynioides group. Relationships within this large, geographically widespread clade are largely unresolved and low DNA-sequence variation within it suggests a recent radiation followed by isolation in south-western and eastern Australia. All endemic Tasmanian Persoonia (Gunnii group taxa) are unresolved at the second-most basal node of the Persoonieae. Our results suggest that the Rufiflora group should be treated as a new genus and that the infrageneric taxonomy of Persoonia requires minor amendment.

Mimosa subseries Dolentes Barneby and Brevipedes Barneby are ecologically and morphologically high-diversified infrageneric taxa of this genus in southern South America. We performed a cytogenetical and morphological analysis of both subseries. Chromosome numbers from accessions throughout the area of distribution were studied. The chromosome numbers 2n = 8x = 104 for M. dolens subsp. callosa (Benth.) Barneby, M. dolens subsp. acerba varieties acerba (Benth.) Barneby, latifolia (Benth.) Barneby and rudis (Benth.) Barneby, M. dolens subsp. rigida var. rigescens (Benth.) Barneby, var. anisitsii (Lindm.) Barneby and var. foliolosa (Benth.) Barneby; and 2n = 4x = 52 for M. sceptrum Barneby, M. aff. custodis Barneby and M. dolens var. pangloea Barneby are presented for the first time. Their karyotypes were symmetric, with small chromosomes. There were several areas with taxa growing in sympatry, occasionally with intermediate forms. No diploids were found, which suggests the presence of either a declining polyploid complex or ancient polyploidy in the clade of southernmost representatives of M. series Mimosa, the most derived of the genus. Some vegetative, inflorescence and carpological characters seem to be associated with chromosome duplication. The distribution pattern of the cytotypes suggests events of chromosome duplication in centres of diversity and expansion of octoploids to the southernmost areas of distribution. Our findings support the importance of polyploidy in the morphological diversity, distribution and speciation of this complex.