Margaret M. Heslewood

A molecular estimate of the phylogeny of Styphelieae (Ericaceae)

Parsimony analyses of sequence data derived from two regions of the chloroplast genome, matK and the atpB-rbcL intergenic spacer, separately and together, are reported for Styphelieae. Taxonomic sampling includes representatives of all currently accepted genera apart from the two non-Australian monotypics, Cyathopsis Brongn. & Gris and Decatoca F.Muell., and of all subgenera or informal infrageneric groups except for Trochocarpa subgenus Pseudocyathodes Sleumer. A well resolved estimate of the phylogeny of the tribe is obtained, with high levels of jackknife support for terminal groupings. The results provide support for the current concepts of Acrotriche R.Br., Androstoma Hook.f., Croninia J.M.Powell, Cyathodes Labill. sensu Weiller, Leptecophylla C.M.Weiller, Leucopogon R.Br. sensu Taaffe et al., Pentachondra R.Br., Planocarpa C.M.Weiller and Trochocarpa R.Br., but the following genera appear paraphyletic: Astroloma R.Br., Brachyloma Sond., Cyathodes sensu Labill., Leucopogon R.Br. sensu lato, Lissanthe R.Br., Monotoca R.Br. and Styphelia Sm. (sensu Bentham). Several robust clades are identified as potential new genera but formalisation of nomenclatural changes is left, pending morphological analyses of the various clades to identify synapomorphies with which to characterise generic groupings. The general approach to be adopted in this endeavour is discussed, with narrower generic concepts being favoured as more informative and less disruptive of the existing nomenclature.

Generic concepts in Styphelieae (Ericaceae): the Cyathodes group

Non-molecular and atpB-rbcL spacer sequence datasets for 38 taxa representing Cyathodes Labill. sensu lato and its relatives, together with several outgroups from Styphelieae, Oligarrheneae, Epacreae and Archerieae, were subjected to cladistic analyses. The monophyly of Cyathodes sensu Weiller, Leptecophylla Weiller, Lissanthe R.Br. sensu Crayn et al. and Planocarpa Weiller is supported. Cyathopsis Brongn. & Gris is expanded to include two other New Caledonian species, Styphelia violaceospicata (Guillaumin) McPherson and S. albicans (Brongn. & Gris) Sleumer. Androstoma Hook.f. is redefined to include Leucopogon milliganii (F.Muell.) Rodway. Leucopogon durus Benth. is transferred to Acrotriche R.Br. Two new genera are described: Acrothamnus C.J.Quinn, comprising at least five species in eastern Australia, New Zealand, New Guinea and the Pacific; Agiortia C.J.Quinn, comprising three species in north-eastern New South Wales and south-eastern Queensland. Keys to the species of Acrothamnus, Agiortia, Androstoma and Cyathopsis are provided.

A multi-locus molecular phylogeny of the Lepidoziaceae: Laying the foundations for a stable classification

The Lepidoziaceae, with over 700 species in 30 genera, is one of the largest leafy liverwort families. Despite receiving considerable attention, the composition of subfamilies and genera remains unsatisfactorily resolved. In this study, 10 loci (one nuclear 26S, two mitochondrial nad1 and rps3, and seven chloroplast atpB, psbA, psbT-psbH, rbcL, rps4, trnG and trnL-trnF) are used to estimate the phylogeny of 93 species of Lepidoziaceae. These molecular data provide strong evidence against the monophyly of three subfamilies; Lepidozioideae, Lembidioideae and Zoopsidoideae, and seven of the 20 sampled genera; Lepidozia, Telaranea, Kurzia, Zoopsis, Lembidium, Paracromastigum and Chloranthelia. Several robust clades are recognised that might provide the basis for a revised subfamily circumscription including a narrower circumscription of the Lepidozioideae and a more inclusive Lembidioideae. Neogrollea notabilis is returned to the Lepidoziaceae and Megalembidium insulanum is placed in the Lembidioideae.

By how much do we underestimate species diversity of liverworts using morphological evidence? An example from Australasian Plagiochila (Plagiochilaceae: Jungermanniopsida)

As a framework for revisionary study of the leafy liverwort Plagiochila in Australia, two methods for species delimitation on molecular sequence data, General Mixed Yule Coalescence model (GMYC) and Automatic Barcode Gap Discovery (ABGD) were applied to a dataset including 265 individuals from Australia, New Zealand, and the Pacific. Groups returned by GMYC and ABGD were incongruent in some lineages, and ABGD tended to lump groups. This may reflect underlying heterogeneity in the history of diversification within different lineages of Plagiochila. GMYC from trees calculated using three different molecular clocks were compared, in some lineages different primary species hypotheses were returned by analyses of trees estimated under different clock models, suggesting clock model selection should be a routine component of phylogeny reconstruction for tree-based species delimitation methods, such as GMYC. Our results suggest that a minimum of 71 Plagiochilaceae species occur in Australasia, 16 more than currently accepted for the region, comprising 8 undetermined species and 8 synonyms requiring reinstatement. Despite modern taxonomic investigation over a four decade period, (1) real diversity is 29% higher than currently recognized; and (2) 12 of 33, or 36%, of currently accepted and previously untested Australasian species have circumscription issues, including polyphyly, paraphyly, internal phylogenetic structure, or combinations of two or more of these issues. These both reflect the many challenges associated with grouping decisions based solely on morphological data in morphologically simple yet polymorphic plant lineages. Our results highlight again the critical need for combined molecular-morphological datasets as a basis for resolving robust species hypotheses in species-rich bryophyte lineages.

A phylogeny of Lophocoleaceae-Plagiochilaceae-Brevianthaceae and a revised classification of Plagiochilaceae

The Lophocoleaceae-Plagiochilaceae-Brevianthaceae clade is a largely terrestrial, subcosmopolitan lineage of jungermannialean leafy liverworts that may include significantly more than 1000 species. Here we present the most comprehensively sampled phylogeny available to date based on the nuclear ribosomal internal transcribed spacer region and the chloroplast markers rbcL and rps4 of 372 accessions. Brevianthaceae (consisting of Brevianthus and Tetracymbaliella) form a sister relationship with Lophocoleaceae; this lineage is in turn sister to Plagiochilaceae. Plagiochila is resolved monophyletic subsequent to exclusion of Plagiochila radiculosa; this species is placed in a new genus Cryptoplagiochila. Chiastocaulon and a polyphyletic Acrochila nest in Plagiochilion; these three genera are united under Chiastocaulon to include the Plagiochilaceae species with dominating or exclusively ventral branching. The generic classification of the Lophocoleaceae is still unresolved. We discuss alternative approaches to obtain strictly monophyletic genera by visualizing their consistence with the obtained consensus topology. The presented phylogeny will serve as a basis for follow-up studies including several thousand accessions. These studies will enable revision of current hypotheses on species diversity and distribution of Lophocoleaceae-Plagiochilaceae-Brevianthaceae and allow for a reconstruction of their evolution in time and space.

Contrasting levels of connectivity and localised persistence characterise the latitudinal distribution of a wind-dispersed rainforest canopy tree

Contrasting signals of genetic divergence due to historic and contemporary gene flow were inferred for Coachwood, Ceratopetalum apetalum (Cunoniaceae), a wind-dispersed canopy tree endemic to eastern Australian warm temperate rainforest. Analysis of nine nuclear microsatellites across 22 localities revealed two clusters between northern and southern regions and with vicariance centred on the wide Hunter River Valley. Within populations diversity was high indicating a relatively high level of pollen dispersal among populations. Genetic variation was correlated to differences in regional biogeography and ecology corresponding to IBRA regions, primary factors being soil type and rainfall. Eleven haplotypes were identified by chloroplast microsatellite analysis from the same 22 localities. A lack of chloroplast diversity within sites demonstrates limited gene flow via seed dispersal. Network representation indicated regional sharing of haplotypes indicative of multiple Pleistocene refugia as well as deep divergences between regional elements of present populations. Chloroplast differentiation between sites in the upper and lower sections of the northern population is reflective of historic vicariance at the Clarence River Corridor. There was no simple vicariance explanation for the distribution of the divergent southern chlorotype, but its distribution may be explained by the effects of drift from a larger initial gene pool. Both the Hunter and Clarence River Valleys represent significant dry breaks within the species range, consistent with this species being rainfall dependent rather than cold-adapted.

Re-evaluation of the genus Babingtonia (Myrtaceae) in eastern Australia and New Caledonia

The validity of the generic concept of Babingtonia Lindl. adopted by Bean (1997a) is tested in the light of molecular and morphological data. Molecular analyses support recognition of segregate genera, none of which is closely related to the type of the genus, Babingtonia camphorosmae, a western Australian species. Two genera, Sannantha and Kardomia, are described as new and a third genus, Harmogia, resurrected from synonymy; new combinations are provided in the new genera. A fourth group, consisting of ‘Babingtonia’ behrii and its allies, appears distinct but, as a predominantly southern group, with numerous western Australian representatives, is not treated further.

Pentachondra dehiscens sp. nov.—an aberrant new member of Styphelieae

A new species of Styphelieae collected from the Blue Mountains region of New South Wales is described. Cladistic analyses of morphological and molecular data show that the species has a strong affinity with the genus Pentachondra. The genus is redefined to accommodate the following features of the new species: a drupaceous fruit with 6–11 locules in which the mesocarp splits to release the separate pyrenes at maturity and a more complex inflorescence.

An integrative revision of Dinckleria (Plagiochilaceae: Jungermanniopsida)

Abstract. On the basis of variation in molecular sequence data and morphology, three species are recognised within Dinckleria. The generitype D. pleurata is widespread in Tasmania and New Zealand and has outlier populations in Victoria, and in rainforests around the New South Wales–Queensland border. Dinckleria fruticella is endemic to New Zealand, records of this species from Tasmania and Queensland are based on misidentifications. The widespread Malesian species Plagiochila singularis is transferred to Dinckleria, and newly reported for Australia and Vanuatu. In Australia, this species is known by two collections, one from the Atherton Tableland the other from the Paluma Range. Dinckleria can be distinguished from other genera of Plagiochilaceae by the presence of papillae on leaf-cell surfaces in combination with monomorphic leafy shoots arising from a basal stolon, the stolons originating by ventral-intercalary branching, presence of cell surface wax, and the restriction of rhizoids to the ventral merophyte.

The genera Chiastocaulon, Cryptoplagiochila and Pedinophyllum (Plagiochilaceae) in Australia

Abstract. Molecular and morphological data support the recognition of seven species of Chiastocaulon in Australia, of which four, namely C. braunianum and C. geminifolium comb. nov. from tropical north-eastern Queensland and C. proliferum and C. flamabilis sp. nov. from Tasmania (and New Zealand), represent new records. The other three species accepted for Australia are C. biserialis, C. dendroides and C. oppositum. Chiastocaulon conjugatum is excluded from the Australian flora, because previous Australian records are based on misidentifications of C. braunianum and Plagiochila retrospectans. Pedinophyllum monoicum, reported for Australia from a single locality in Victoria, is excluded from the Australian flora because all credible records are based on misidentifications of Syzygiella tasmanica. The Papua New Guinean Chiastocaulon takakii comb. nov. is reinstated from synonymy under C. dendroides on the basis of morphological evidence. Descriptions and illustrations of all Australian species, and dichotomous keys to species of the Chiastocaulon lineage in Australia and New Zealand, are provided.