Bush Blitz is an innovative and ambitious partnership between the Australian Biological Resources Study, BHP Billiton Sustainable Communities and the Earthwatch Institute (Australia) that aims to fill critical gaps in the knowledge of the biodiversity of Australia ( http://www.bushblitz.org.au). Since its inception in 2009, over 900 putative new species of animals and plants have been discovered in Australian conservation reserves. As a unique approach to surveys in often-remote areas of the Australian outback, the Bush Blitz program has been highly successful and highlights the need for ongoing exploration and research to adequately document the biodiversity of Australia. This special issue of Australian Systematic Botany describes some of the newly discovered species and showcases the botanical results of the Bush Blitz program.

Taxonomic uncertainty exists regarding the circumscription of the following seven phenotypically similar Australian species: Poa crassicaudex Vickery, P. hookeri Vickery, P. labillardierei Steud., P. phillipsiana Vickery, P. poiformis (Labill.) Druce, P. porphyroclados Nees (including P. serpentum Nees) and P. sieberiana Spreng. Multivariate ordination and clustering analyses of morphological data were conducted and the distribution of morphological diversity among taxa was assessed for congruence with current taxonomic boundaries. One-way analyses of variance and Tukey’s honest significant difference tests were applied to identify continuous characters that differentiate taxa. Utility of morphological characters was assessed in light of the distribution of variation among and within taxa. Revisions of P. labillardierei, P. porphyroclados and P. sieberiana circumscriptions are proposed. Accounting for nomenclatural priority, proposed revisions include recognition of P. porphyroclados vars. acris, labillardierei, porphyroclados, and. serpentum, P. sieberiana var. cyanophylla Vickery at species rank, and P. phillipsiana at varietal rank within P. sieberiana. Species boundaries are supported by leaf, culm, panicle, spikelet and floret dimensions. The present study enables increased accuracy in taxonomic identifications for Poa species that are keystones in a range of grassland vegetation types, including critically endangered natural temperate grassland and eucalypt woody grassland ecosystems, therefore contributing to the effective biodiversity monitoring and management of these ecosystems.

Aspleniaceae is one of the largest fern families. It is species-rich in Australasia and the south-western Pacific (ASWP), where approximately 115 species occur. In the current study, the chloroplast regions rbcL, trnL–trnF and rps4–trnS were sequenced for 100 Aspleniaceae samples from ASWP. These data were combined with published sequences for species from New Zealand and other regions for phylogenetic analyses. Species of Aspleniaceae from ASWP were placed in six of the eight previously identified inter-continental clades. The majority of species from ASWP were placed in two of these clades, with the remaining four clades each being represented by three or fewer species. Strong biogeographic affinities with South-east Asia were observed and immigration, rather than local radiations of endemic taxa, appears to have made a more important contribution to patterns of diversity in ASWP. This study supports the current taxonomic practice of recognising two genera, Asplenium L. and Hymenasplenium Hayata, in Aspleniaceae, and identifies future taxonomic work required for the family in this region, including potential synonymising of species, and revision of species complexes or widespread species that are demonstrably non-monophyletic.

Asplenium listeri C.Chr. has been considered endemic to Christmas Island and is one of only two fern species listed as Critically Endangered under Australia’s Environment Protection and Biodiversity Conservation Act. Its status as a distinct species has been questioned because of morphological similarity to the widespread A. polyodon G.Forst., which also occurs on Christmas Island. Molecular analyses revealed that A. listeri and plants attributed to A. polyodon from coastal limestone in New Caledonia and Vanuatu share the same rbcL, trnL–trnF and rps4–trnS haplotype and that other samples of A. polyodon in Australia and the south-western Pacific belong to three separate molecular lineages. One of these lineages is formed by epiphytic A. polyodon from Christmas Island and has a chloroplast haplotype closely related to that of A. listeri, differing by four mutations. The A. listeri haplotype and each of the three A. polyodon lineages are associated with morphological characters and are all worthy of recognition as separate species. Asplenium listeri is here expanded to include limestone dwelling populations in the Pacific previously assigned to A. polyodon. This greatly extends the geographic range of A. listeri, and its conservation status should be revised accordingly. Application of correct names to all species in the A. polyodon complex requires further molecular sampling throughout its geographic range and clarification of how type material relates to each of the molecular groups.

Species boundaries and relationships were investigated in the Asplenium paleaceum (Aspleniaceae) species complex from eastern Australia, using AFLP fingerprinting and chloroplast trnL–trnF and rps4–trnS and nuclear pgiC DNA sequences. Phenetic analyses of AFLP data resulted in the following five distinct groups: (1) A. carnarvonense, (2) A. bicentenniale (including nearby collections originally identified as A. paleaceum), (3) A. paleaceum with both aborted and normal spores, (4) one population of putative tetraploid A. attenuatum var. indivisum from south Queensland, and (5) remaining octoploid A. attenuatum populations and several putative hybrids. Taxonomic revision of this complex will require morphological re-circumscription of the current species and recognition of a new species if these AFLP groups are taken to represent separate species. The chloroplast regions, morphology and pgiC together provide good evidence that an Asplenium of unconfirmed identity, A. sp. ‘Kroombit Tops’, is an allopolyploid with a species of the A. paleaceum chloroplast clade, probably A. paleaceum, and distantly related A. polyodon as parents. Further study is required to determine the complete ancestry of the other species of the A. paleaceum complex.

Two new species in the genus Trapelia, namely, T. calvariana Kantvilas & Lumbsch from the Tasmanian highlands and T. thieleana Kantvilas & Lumbsch from south-western Western Australia, are described. Examination of ascus types and analyses of DNA-sequence data confirmed the inclusion of these taxa in Trapelia sensu lato, but raised questions concerning the homogeneity of the genus as currently circumscribed and, in particular, the generic classification of T. lilacea Kantvilas & Elix.

Australian species of Chara L. sect. Charopsis (Kütz.) Leonh. are revised. Multivariate analysis supports recognition of four species: Chara braunii C.C.Gmel., C. evanida Casanova, C. karolii Casanova and C. muelleri (A.Braun) F.Muell. These taxa are described and illustrated, and a key is provided.

Field studies have provided an improved understanding of a known undescribed species of Tricoryne R.Br. and also shown that two or three separate species are included in an existing taxonomic concept. Two new species are described here, namely, T. tuberosa Keighery & T.D.Macfarl. and T. soullierae T.D.Macfarl. & Keighery. Tricoryne tuberosa has an extensive range in the northern wheatbelt and adjacent pastoral areas of south-western Western Australia. It has large root tubers, the leaves are withered at flowering time, and it forms clonal groups by long rhizomatous shoots. Tricoryne soullierae has a restricted distribution in remnant vegetation in the northern wheatbelt. It has fibrous roots and is conspicuously leafy when flowering.

Lomandra marginata T.D.Macfarl. & Conran is described as a new species and illustrated by photographs and a distribution map. Recognised initially from vegetative plants during a biological survey at Lochada Station, it was realised subsequently that the species is widespread from Geraldton to Corrigin. However, it apparently flowers only occasionally under favourable conditions, so earlier collections were mostly vegetative. Lomandra marginata is placed in L. series Sparsiflorae on the basis of possessing a narrow floral bract that does not encircle the pedicel and a bracteole, when present, offset rather than opposite the bract. It has distinctive membranous leaf margins resembling those of the related genus Chamaexeros and the longest pedicels in the genus, mostly 10–16 mm long, on which are borne white flowers resembling those of L. effusa (Lindl.) Ewart. Although L. effusa is the most similar species in flower and inflorescence and is also a member of L. series Sparsiflorae, it differs vegetatively by having distinctly two-toothed leaf tips.

This study presents a molecular phylogeny of Zieria Sm., a genus of shrubs and small trees, with 59 species in Australia and one endemic to New Caledonia. The phylogeny is based on four cpDNA markers and 116 samples representing all species of Zieria except one, and the monotypic outgroup Neobyrnesia suberosa. The New Caledonian species, Z. chevalieri, was resolved as sister to a well supported clade of all Australian taxa. There was widespread incongruence between the cpDNA tree and species-level taxonomy, with 14 species shown as polyphyletic or paraphyletic. These included widespread species (e.g. Z. smithii and Z. arborescens, each falling in at least four well supported clades) and some with narrow geographic ranges (e.g. Z. alata and Z. oreocena). No species represented by three or more samples was resolved as monophyletic. We suggest that a combination of factors explains this incongruence, including regional cpDNA introgression (chloroplast capture), incomplete lineage sorting and inappropriate taxonomic boundaries. The cpDNA phylogeny provides useful insight into the evolution of Zieria but, because of its complexity, does not provide a clear basis for assessing phylogenetic relationships and monophyly of taxa. Better understanding of relationships, taxon limits and evolutionary processes in Zieria will require comparisons with nuclear DNA markers and critical assessment of morphological and genetic variation in widespread species.

Molecular analysis of the newly reinstated genus Synostemon F.Muell. (Phyllanthaceae, Phyllantheae), using ITS sequence data from the now densely sampled genus, confirmed that the previously recognised ‘Queensland clade’ consists of Synostemon albiflorus (F.Muell. ex Müll.Arg.) Airy Shaw, S. sphenophyllus Airy Shaw, Sauropus podenzanae (S.Moore) Airy Shaw and the undescribed Synostemon spinescens, sp. nov. ined., the latter being validated here as S. spinosus I.Telford & J.J.Bruhl. Morphological synapomorphies for the clade are as follows: linear, apiculate anthers that are connivent but only basally connate, and thickened, clavate, recurved stigmas. A new combination is provided under Synostemon for Sauropus podenzanae as Synostemon podenzanae (S.Moore) I.Telford & Pruesapan and Sauropus convallarioides J.T.Hunter & J.J.Bruhl is formally placed in synonymy under Synostemon sphenophyllus. Descriptions, distributional data and notes on ecology and conservation status are provided for these species. Phyllanthus albiflorus F.Muell. ex Müll.Arg., the basionym of Synostemon albiflorus, is lectotypified.

Brachychiton chrysocarpus Cowie & Guymer from Fish River Station in the north-western part of the Northern Territory is described as a new species. It is compared with B. tuberculatus Guymer and B. xanthophyllus Guymer, but differs especially in the softer finer indumentum, shorter caducous stipules, slender paniculate, open inflorescence, the weakly tuberculate follicles and other characters. It appears to be restricted to Eucalyptus tectifica woodland on slopes of ∼17° associated with ferruginous sandstone of the Waterbag Creek formation. Its conservation status is discussed and assessed.

Goodenia cravenii R.L.Barrett & M.D.Barrett, G. maretensis R.L.Barrett, Goodenia heterotricha M.D.Barrett & R.L.Barrett and Lechenaultia mimica M.D.Barrett & R.L.Barrett are described as new species from the northern Kimberley region of Western Australia. Goodenia cravenii (subg. Goodenia sect. Amphichila DC.) is the smallest species known in the family. Goodenia maretensis (subg. Goodenia sect. Goodenia subsect. Ebracteolatae K.Krause) is known only from the Maret Islands group in the Bonaparte Archipelago. Goodenia heterotricha (subg. Goodenia sect. Goodenia subsect. Ebracteolatae K.Krause) was discovered during a Bush Blitz survey on Home Valley Station in May 2014. Modified keys to these species are presented. Lechenaultia mimica (sect. Latouria (Endl.) Benth.) is known only from the Harding Range and may represent the first instance of floral mimicry to be reported in the genus Lechenaultia. Seed article micromorphology in tropical annual species of Lechenaultia R.Br. is discussed and a key to species is provided. A putative elaiosome, the first report for the genus, was observed on the seed article of L. ovata. All species described here are of conservation priority and are illustrated.