Taxonomic delineation of closely related taxa can be difficult, particularly in regions such as southern Western Australia where a highly diverse flora exhibits complex patterns of subtle morphological variation and genetic structuring and where some taxa have highly disjunct populations. A combined approach utilising highly variable, non-coding chloroplast gene regions and morphological data is used here to help delimit cryptic taxa in the rare Western Australian species Pityrodia scabra A.S.George. The species comprises disjunct populations over 400 km of the Western Australian wheatbelt from near Wyalkatchem, Southern Cross and Lake Lefroy. Morphological features such as leaf phyllotaxy, calyx size and indumentum vary among the populations and provide some evidence for cryptic taxa. Phylogenetic analyses based on cpDNA psbA–trnH and psbD–trnT and nuclear external transcribed spacer (ETS) sequences revealed genetic distinctiveness between the Wyalkatchem (type) population and the Southern Cross and Lake Lefroy populations. This evidence, when used in conjunction with the morphological differences, provides support for the recognition of the new subspecies described herein as Pityrodia scabra subsp. dendrotricha K.A.Sheph. subsp. nov. This new subspecies is of conservation concern because it is currently known only from a few, isolated populations; the typical subspecies remains Critically Endangered because it comprises one extant population. A description of both subspecies, a key and images are provided.

Molecular data have revealed many morphologically cryptic species. More surprising than lack of difference, however, is that morphological variation and complex patterns of overlapping features can mask cryptic species. We employ geometric morphometric methods (GMM) to explore patterns of variation within four liverwort species, three of which were previously attributed to Lejeunea tumida Mitt. Each species exhibited considerable variation within, and overlap among, species in size and shape, independent of degree of relatedness. Most variation was expressed within individuals, suggesting that the observed breadth of variation was within the developmental capacity of single genotypes. Size and shape variation within, and consequently overlap among, individuals resulted primarily from variance in growth of shoots. Inter-specific differences were swamped by intra- and inter-individual variation. We coupled GMM with multivariate methods for outlier removal, and simple averaging of individuals to explore whether intra-individual variation could be reconciled to maximise the inter-species difference, facilitating resolution of cryptic species despite extensive morphological continuity and overlap. Unfortunately, outlier removal did not achieve separation among species, because removing extremes failed to eliminate overlap resulting from within-species variation. Individual averaging was partially successful in extracting L. tumida as a discrete entity but did not segregate the remaining three species. Although the challenges for morphology-based identification of cryptic species are significant, GMM provide one of the best sets of methods for identifying and communicating any subtle morphological differences that may exist.

A morphometric study of the Olearia phlogopappa species complex from throughout south-eastern Australia has confirmed species boundaries and resolved the infraspecific taxonomy of two species. It has shown O. phlogopappa (Labill.) DC., O. stellulata (Labill.) DC., O. lirata (Sims) Hutch., O. rugosa (F.Muell. ex W.Archer bis) Hutch. and O. brevipedunculata N.G.Walsh to be non-overlapping entities with unique morphological characters. O. stellulata is circumscribed to include only southern and western Tasmanian populations and those from the Otways and Wilsons Promontory in southern Victoria. O. rugosa is restricted to Victoria and a few isolated populations on Flinders Island and northern Tasmania. Four previously noted variants of O. rugosa from Victoria are here described as subspecies, along with the description of a fifth subspecies from northern Tasmania. Infraspecific boundaries of O. phlogopappa are here revised to include nine subspecies, six of which were previously included as varieties, and descriptions are made of three new subspecies.