The Tetratheca hirsuta Lindl. species complex from south-west Western Australia is one of the last unresolved complexes in this Australian endemic genus, and comprises the highly variable T. hirsuta, two rare, phrase-named taxa, and the closely allied T. hispidissima Steetz. An integrative approach, incorporating multivariate morphometric analysis and molecular phylogenetic and phenetic analyses of nrDNA (ETS) and cpDNA (ndhF–trnL, rpl16, trnS–trnG5′ 2S), was used to investigate taxonomic boundaries within the complex. Morphological data showed clear divergence within the complex, and allowed several taxonomically uncertain individuals to be assigned. Phenetic and phylogenetic analyses of ETS showed substantial congruence with morphology, indicating that the groups recognised through morphometric analyses are also genetically divergent. By comparison, the chloroplast regions yielded incongruent gene trees, perhaps owing to incomplete lineage sorting, hybridisation or slow evolution of cpDNA. The present results support the recognition of the following four taxa: a morphologically and geographically expanded T. hispidissima, which is highly divergent from the remainder of the complex, and a closer grouping of T. hirsuta subsp. boonanarring Joyce & R.Butcher subsp. nov., T. hirsuta subsp. viminea (Lindl.) Joyce comb. et stat. nov. and T. hirsuta subsp. hirsuta.

The genus Dolichandrone (Fenzl) Seem. (Bignoniaceae) has been revised for Australia. Five species and one subspecies are recognised and described. Dolichandrone occidentalis Jackes is newly described, as well as a new subspecies D. alternifolia subsp. variabilis Jackes. A key to the species and distribution maps are provided.

A new subaerophytic cyanobacterium, Ewamiania thermalis gen. et sp. nov., was isolated from a thermal spring complex in tropical, north-eastern Australia and characterised using combined morphological and phylogenetic attributes. It formed blackish-green hemispherical caespitose mats that began as small circular tufts, maturing to form dense mats up to several metres long. It grew along the crests of the minidams just above the thermal waters as well as along some of the shallow unconfined areas of vent-discharge aprons. Morphologically, Ewamiania is most similar to members of the Scytonemataceae. Filaments were isopolar, cylindrical, straight or flexuous, densely arranged and erect, often parallely fasciculate, with tolypotrichoid false-branching, rarely with scytonematoid false-branching. Vegetative cells were short barrel-shaped or isodiametric, slightly constricted at the cross-walls, with granulated contents. Sheaths were firm, thick, lamellated, uncoloured to yellowish or darkly yellow–brown in colour, cylindrical and closed at the apex. Heterocytes were spherical or ovoid in shape, and occurred in both basal and intercalary positions, generally solitary, but sometimes up to two or three in a series, developing particularly at the base of branches. Reproduction occurred by the production of hormogonia by the formation of necridic cells; hormogonia were not constricted at cross-walls and often included terminal heterocytes. Phylogenetic analyses using partial 16S rRNA sequences obtained from a strain of E. thermalis showed that it formed a well supported monophyletic clade, sharing less than 94.3% nucleotide similarity with other cyanobacterial sequences, including putatively related taxa within the Scytonemataceae. It also formed a novel clade in the nifH phylogeny, which was associated with members of the genus Brasilonema M.F.Fiore, Sant’Anna, M.T.P.Azevedo, Komárek, Kastovsky, Sulek & Lorenzi.

Flowers of holoparasitic plants have evolved several adaptations for pollination as part of their parasitic strategies. A study of the petal epidermis may be useful to systematics as well as to the knowledge of ecological and co-evolutionary adaptations between the parasites and their pollinators. The present work is a comparative study of the microsculpture of nectar guides and landing platforms in the flowers of holoparasitic species in the family Orobanchaceae. In total, 285 samples of 39 species from 10 holoparasitic genera (Boschniakia C.A.Mey. ex Bong., Boulardia F.W.Schultz, Cistanche Hoffmanns. & Link, Conopholis Wallr., Diphelypaea Nicolson, Epifagus Nutt., Mannagettaea H.Sm., Orobanche L., Phacellanthus Siebold & Zucc. and Phelipanche Pomel) and as an outgroup, of six additional hemiparasitic genera (Castilleja Mutis ex L.f., Euphrasia L., Orthantha (Benth.) A.Kern., Parentucellia Viv., Rhinanthus L., and Striga Lour.) were analysed using both light and scanning electron microscopy. Types of epidermal cells were characterised, and their distribution on the adaxial and abaxial surfaces of the petals determined. The following four major epidermal types were recognised: tabular rugose striate cells (TRS), areolate cells (AS), papillose conical cells (PCS) and lobular striate cells (PLS). Two main types of trichomes were observed, namely glandular and non-glandular. Our results showed that petal micromorphology may be useful to systematics; its influence in relation to the pollinators is discussed.

Phylogenetic analyses based on 10 molecular markers unquestionably support a sister relationship between Albidella nymphaeifolia and the Caldesia oligococca species group. The type species of the genus Caldesia is excluded from this monophylum. These results are unsurprising in the light of morphological characteristics, but require three new combinations in Albidella to render both Albidella and Caldesia monophyletic. These new combinations are provided here. Under the new circumscription, Albidella shows a disjunct distribution pattern, with one species in the Caribbean region and three species distributed from tropical Africa and along the margins of the Indian Ocean to Australia.

Molecular phylogeny reconstruction has motivated recircumscription of all families and most genera within the Lophocoleinae, and in Plagiochila, the largest genus of this lineage, has refined the sectional classification as well. Here, we extend this ongoing revision in the first study focusing on species from Australasia, a region to date underrepresented in molecular phylogenetic datasets. We reconstructed a phylogeny containing more than 300 individuals from Australasia and the Pacific, and with this tested sectional circumscriptions within the two largely contradictory classifications recently proposed for Plagiochila. Neither scheme satisfactorily captures relationships among species and all sections prove paraphyletic or polyphyletic, with the exception of those defying these properties by virtue of containing only one species. We propose expanding the circumscription of several sections as the best option for achieving a revised classification representing monophyla that remains stable over the short to medium term, given current knowledge. Broader circumscriptions are proposed for section Denticulatae with section Tayloriae as a new synonym; section Arrectae with section Caducifoliae as a new synonym; a reinstated section Deflexifoliae; and section Plagiochila, to include P. trapezoidea; section Belangerianae to include sections Annotinae, Mitteniae and Strombifoliae as new synonyms; and section Durae with section Colensoae as a new synonym. Section Fragmentissimae is applied to the lineage previously named section Deltoideae nom. inval. or section Hodgsoniae nom. inval., as the Tasmanian P. ratkowskiana and New Zealand P. fragmentissima are the same, and sister to other species in the lineage containing P. deltoidea. Morphological characters supporting these groups are identified, but more importantly the proposed revisions provide a robust framework on which informed re-examination of morphology within this variable and species-rich genus can proceed, and we introduce some encouraging avenues in this area.

The phylogeny of Heterocaryum and Suchtelenia was examined using sequence data from the internal transcribed spacer region of the nuclear rDNA (ITS) and plastid trnL intron and trnL–trnF intergenic spacer (trnL–F) regions. Results indicated that Heterocaryum is non-monophyletic because of the inclusion of Suchtelenia calycina (C.A.Mey.) A.DC. Heterocaryum laevigatum (Kar. & Kir.) A.DC. formed a distinct branch sister to S. calycina and remaining Heterocaryum species. Hence, all species of Heterocaryum except H. laevigatum (type species of the genus) are transferred to a new genus, Pseudoheterocaryum. Taxonomic descriptions are presented for Pseudoheterocaryum and Heterocaryum, as well as a diagnostic key to the three genera included in the present study.