The major goal of this study was to re-analyse a published molecular dataset based on ITS and matK sequences of the genus Ceratophyllum (Ceratophyllaceae) within a cladistic framework, operating only with rooted trees. The problem is lack of an identifiable suitable outgroup to Ceratophyllum. We show different ways to root trees and thus resolve the sister group relationships within this genus. We root the trees using an all zero outgroup or a combination of exemplar taxa from among monocots (Acorus), eudcots (Ranunculus) and Chloranthus. Ceratophyllum echinatum was consistently strongly supported as sister to all of the remaining taxa of the genus. This observation is congruent with the earlier results of Les who noted the uniqueness of C. echinatum in a series of comprehensive morphological and biosystematic studies. We, here, transfer C. echinatum to a new and presumably monotypic genus Fassettia Mavrodiev. The exact taxonomic circumscription of Fassettia requires further investigation.

The diagnostic characteristics and distinctiveness of plant taxa have traditionally been based on a combination of geographic and morphological discontinuity. Implicit within these concepts is the notion that morphological variation is fixed and that gene flow among taxa is limited. However, species complexes that comprise a range of more-or-less continuous morphotypes often confound such assumptions and resist formal taxonomic treatment. A range of independent data sources, namely, nucleotide sequences, volatile oils and traditional morphology, were used in an integrative approach to resolve the taxonomic structure within the geographically widespread species complex of Prostanthera lasianthos Labill. We concluded that no dataset has primacy in defining segregate taxa, and that a combination of morphological and molecular data was required to determine the taxa within. As a result, we amended the description of P. lasianthos sens. strict. and recognise the following five new segregate species: Prostanthera largiflorens B.J.Conn & K.Proft, P. lasiangustata J.Carrick ex B.J.Conn & K.Proft, P. rupicola B.J.Conn & K.Proft, P. subalpina B.J.Conn & K.Proft, and P. williamsii B.J.Conn & K.Proft.

Nicotiana is found predominantly in the Americas and Australia, but also has representatives in Africa and the Pacific Islands. All native Australian Nicotiana species belong to section Suaveolentes. The number of species in this section is uncertain and subject to revision. An example of this uncertainty is the taxonomic status of a South Australian Nicotiana accession colloquially termed ‘Corunna’. Here, we report sequences for nuclear and plastid markers for N. sp. Corunna (D.E.Symon 17088) and accessions of two other Australian species, N. burbidgeae and N. benthamiana. Phylogenetic comparison of these sequences with those of other members of Nicotiana places all three taxa in N. section Suaveolentes and shows that ‘Corunna’ represents a distinct phylogenetic lineage in a well supported clade along with N. goodspeedii, N. maritima, N. amplexicaulis and N. suaveolentes. Phenetic analysis of floral characters also supports recognition of N. sp. Corunna (D.E.Symon 17088) as a distinct species, which we describe here as Nicotiana paulineana Newbigin & P.M.Waterh., sp. nov. The enlarged molecular dataset described here contributes to a better understanding of taxonomic relationships within the section.

A molecular phylogeny of Chloantheae (Lamiaceae) based on a three-marker chloroplast and nuclear DNA dataset was used to test the monophyly of Lachnostachys Hook., Newcastelia F.Muell. and Physopsis Turcz. A clade consisting of at least one species from each of these genera was recovered separately from the ‘core’ Lachnostachys, Newcastelia and Physopsis clades. The members of this composite clade are here transferred to the new genus, Apatelantha T.C.Wilson & M.J.Henwood, which can be recognised by a combination of the base of the style being glabrous or with only non-glandular trichomes (glandular trichomes lacking), apex of corolla lobes (when present) acute to obtuse (not extending into an apical protrusion) and thin-textured (not distinctively thickened), pherophylls subtending three flowers, and anther connectives glabrous (sessile glands absent). A description of the new genus, together with new combinations for five species of Apatelantha, and amended descriptions of Lachnostachys, Newcastelia and Physopsis, are provided. A new species, Newcastelia clavipetala T.C.Wilson & Radunz, is described and illustrated. A taxonomic key to genera of Chloantheae, and keys to species of Lachnostachys, Newcastelia, Physopsis and Apatelantha are provided.

Pycnandra Benth., a member of subfamily Chrysophylloideae (Sapotaceae), is the largest endemic genus in New Caledonia and is subdivided into six subgenera. It circumscribes 59 species, plus an additional three described here, and nine additional species that remain undescribed for various reasons. We here use nrDNA data of ETS, ITS, and RPB2, analyse it within a Bayesian framework using BEAST, and place the new species in their respective subgenera. Pycnandra perplexa Swenson & Gâteblé is placed in subgenus Achradotypus and given a preliminary IUCN Red List assessment of Near Threatened (NT). It is confined to the ultramafic massif of southern Grande Terre and separated from the similar species P. griseosepala Vink, which is confined to non-ultramafic mountains north of the large southern ultramafic plateau. Pycnandra kopetoensis Munzinger & Swenson and P. margueriteae Munzinger & Swenson are two new micro-endemic species known only from their type localities, where habitats have been destroyed by deforestation, deliberate fires and mining activities. Pycnandra kopetoensis is named after Mount Kopéto, placed in subgenus Leptostylis, and given a preliminary assessment as Critically Endangered (CR). Pycnandra margueriteae is from a small remnant forest near Bourail and categorised as Critically Endangered (CR). Revised identification keys for subgenus Achradotypus, Leptostylis and Pycnandra are provided.