Australian Tropical Herbarium

The genus Dracophyllum Labill. (Ericaceae) has a fragmented distribution in Australasia, but reaches the greatest level of species richness and morphological diversity in New Zealand. We investigated evolutionary processes that contribute to this disparity in species richness by comparing DNA sequences from members of Dracophyllum, its close relatives Richea Labill. and Sphenotoma R. Br. ex Sweet (together constituting tribe Richeeae Crayn & Quinn), along with more distant relatives in the Ericaceae. We created complementary data sets for the chloroplast-encoded genes matK and rbcL. Parsimony, Bayesian, and maximum likelihood analyses were conducted to assess the robustness of our phylogenetic inferences. The results were largely congruent and, when analyzed in combination, provided greater resolution. In our analyses, tribe Richeeae formed a monophyletic group that diverged during the Eocene (at least 33.3 million years ago [Ma]) with a crown radiation during the Early Miocene (at least 16.5 Ma) that resulted in two disjunct lineages. This date corresponds roughly to the onset of aridification in central Australia. The southern Western Australian genus Sphenotoma formed an isolated evolutionary lineage, while Dracophyllum and Richea together formed a second lineage restricted to eastern Australia, Lord Howe Island, New Caledonia, and New Zealand. The relationships of the Tasmanian endemic, D. milliganii Hook. f., remain an enigma. It was ambiguously placed as sister to Sphenotoma or to the Dracophyllum–Richea clade. We recovered two distinct lineages, traditionally recognized as Richea sect. Cystanthe (R. Br.) Benth. and Richea sect. Dracophylloides Benth., which were nested within Dracophyllum. The Lord Howe Island endemic, D. fitzgeraldii F. Muell., emerged as sister to an eastern Australian clade of Dracophyllum. Our evidence suggests that the New Caledonian and New Zealand species of Dracophyllum dispersed from Australia; we document two independent episodes of long-distance dispersal in the Late Miocene to Early Pliocene. Low levels of sequence divergence suggest a rapid and recent species radiation in these two island archipelagos largely within the last three to six million years. This radiation accompanied Pliocene uplift of the New Zealand Southern Alps and episodes of glaciation during the Pleistocene. Because Dracophyllum is paraphyletic and Richea is polyphyletic, the taxonomic circumscription of these genera requires revision.

Khaya senegalensis (African mahogany or dry-zone mahogany) is a high-value hardwood timber species with great potential for forest plantations in northern Australia. The species is distributed across the sub-Saharan belt from Senegal to Sudan and Uganda. Because of heavy exploitation and constraints on natural regeneration and sustainable planting, it is now classified as a vulnerable species. Here, we describe the development of microsatellite markers for K. senegalensis using next-generation sequencing to assess its intra-specific diversity across its natural range, which is a key for successful breeding programs and effective conservation management of the species. Next-generation sequencing yielded 93,943 sequences with an average read length of 234 bp. The assembled sequences contained 1030 simple sequence repeats, with primers designed for 522 microsatellite loci. Twenty-one microsatellite loci were tested with 11 showing reliable amplification and polymorphism in K. senegalensis. The 11 novel microsatellites, together with one previously published, were used to assess 73 accessions belonging to the Australian K. senegalensis domestication program, sampled from across the natural range of the species. STRUCTURE analysis shows two major clusters, one comprising mainly accessions from west Africa (Senegal to Benin) and the second based in the far eastern limits of the range in Sudan and Uganda. Higher levels of genetic diversity were found in material from western Africa. This suggests that new seed collections from this region may yield more diverse genotypes than those originating from Sudan and Uganda in eastern Africa.

Abstract— The taxonomy of the Polypodiaceae subfamily Microsoroideae is highly problematic, especially with respect to the circumscription of the highly variable and non-monophyletic genus Microsorum . Using phylogenetic analyses and morphological evidence, we demonstrate that sixteen taxa typically treated in the genera Microsorum and Colysis are not closely related to those groups and instead belong to three clades that are successive sister groups to the Old-World ant-fern genus, Lecanopteris . We use the available genus name Dendroconche for one of these clades and propose the new genera Bosmania and Zealandia to accommodate the remaining two groups. We provide a description and identify morphological synapomorphies for each of the genera, make new combinations and designate lectotypes where necessary, and present keys and descriptions for all relevant species. We also discuss the evolution of ant-fern associations in the lecanopteroid ferns and highlight the need for additional taxonomic work in the subfamily. The following new combinations are provided: Bosmania lastii , B . leandriana , B . membranacea , Dendroconche ampla , D . latilobata , D . linguiforme , D . sayeri , D . scandens , D . varians , Zealandia novae-zealandiae , Z . powellii , Z . pustulata , Z . pustulata subsp . howensis , and Z . vieillardii .

Background and Aims: Many African genera of the Amaranthaceae exhibit unique inflorescences that include sterile flowers modified to hooks or spines. Considering that the abundance of large terrestrial herbivores increased on the African continent with the expansion of grassland and savannah ecosystems, modified sterile flowers could have been an innovation that boosted the diversification of an African achyranthoid clade of Amaranthaceae, with large animals serving dispersal. Methods: We generated an extensively sampled phylogeny comprising 26 of the 31 achyranthoid genera as well as representatives of all other lineages of Amaranthaceae. Phylogenetic tree inference employed four genomic regions, using parsimony, likelihood and Bayesian inference methods. We estimated divergence times, evaluated trait-dependant changes and species diversification rates using state-dependent speciation and extinction models, and reconstructed ancestral character states for modified sterile flowers. Key Results: The achyranthoids were found to be a major clade of the Amaranthaceae, comprising mostly African members. Phylogenetic relationships within this clade were well resolved and supported two main subclades. Several genera were found to be polyphyletic. Our results indicate that the achyranthoids started to diversify ~28 million years ago, and that modified sterile flowers evolved multiple times. An asymmetry in transition rates towards the gain of sterile flowers was observed, whereas no trait-dependent increase in species diversification rates was detected. Bayesian rate heterogeneity analyses indicated that the achyranthoids diversified without significant rate shifts. Conclusions: The accumulation of modified sterile flowers within achyranthoids appears to result from the higher transition rates in favour of modified sterile flowers. Multiple gains suggest an adaptive value for this trait. However, epizoochory does not appear to fuel species diversification, possibly due to extensive gene flow through regularly migrating mammals, which limits the possibility of speciation by isolation.

BACKGROUND: Full floristic data, tree demography, and biomass estimates incorporating non-tree lifeforms are seldom collected and reported for forest plots in the tropics. Established research stations serve as important repositories of such biodiversity and ecological data. With a canopy crane setup within a tropical lowland rainforest estate, the 42-ha Daintree Rainforest Observatory (DRO) in Cape Tribulation, northern Australia is a research facility of international significance. We obtained an estimate of the vascular plant species richness for the site, by surveying all vascular plant species from various mature-phase, remnant and open vegetation patches within the site. We also integrate and report the demography and basal areas of trees ≥ 10 cm diameter at breast height (dbh) in a new 1-ha core plot, an extension to the pre-existing forest 1-ha plot under the canopy crane. In addition, we report for the canopy crane plot new demography and basal areas for smaller-size shrubs and treelets subsampled from nine 20 m(2) quadrats, and liana basal area and abundance from the whole plot. The DRO site has an estimated total vascular plant species richness of 441 species, of which 172 species (39%) are endemic to Australia, and 4 species are endemics to the Daintree region. The 2 x 1-ha plots contains a total of 262 vascular plant species of which 116 (1531 individuals) are tree species ≥ 10 cm dbh. We estimate a stem basal area of 34.9 m(2) ha(-1), of which small stems (tree saplings and shrubs <10cm dbh) and lianas collectively contribute c.4.2%. Comparing the stem density-diversity patterns of the DRO forest with other tropical rainforests globally, our meta-analysis shows that DRO forests has a comparatively high stem density and moderate species diversity, due to the influence of cyclones. These data will provide an important foundation for ecological and conservation studies in lowland tropical forest. NEW INFORMATION: We present a floristic checklist, a lifeform breakdown, and demography data from two 1-ha rainforest plots from a lowland tropical rainforest study site. We also present a meta-analysis of stem densities and species diversity from comparable-sized plots across the tropics.

[Extract] In an attempt to identify areas of the world that represent outstanding examples of ecological integrity, Plumptre et al. (2021) concluded that just 2.8% of Earth's terrestrial area could be considered to qualify. This analysis contrasts with other global assessments that show the extent of areas important for ecological integrity to be at least an order of magnitude higher (Newbold et al., 2016; Watson et al., 2016a; Beyer et al., 2020; Grantham et al., 2020; Hansen et al., 2020; Mokany et al., 2020; Riggio et al., 2020; Williams et al., 2020; De Palma et al., 2021). Plumptre et al. (2021) further argue their methodology and findings can inform Key Biodiversity Area (KBA) delineation.

This is the second in a five-part series of papers that constitute a synopsis of the family Calymperaceae for Australia. It treats the genera Arthrocormus (one species), Exostratum (one species) and Leucophanes (four species) and includes detailed descriptions and illustrations of each species, critical identification features, notes on similar species, and distribution maps.

This is the first of five papers constituting a synopsis of the family Calymperaceae for Australia. An expanded concept of the family is followed, including Arthrocormus, Exostratum and Leucophanes as well as the traditional genera Calymperes, Mitthyridium and Syrrhopodon. A key to genera is provided.

We here describe Dianella lignosa R.L.Barrett &amp; M.D.Barrett (Asphodelaceae) as a new species from the Kimberley region of Western Australia, previously included under Dianella longifolia R.Br. The new species is readily identifiable by its thick, woody lateral rhizomes, and also differs from D. longifolia in leaf and floral characters.

Three species of liverworts are reported as new to Australia, all from the Australian Wet Tropics bioregion: Colura corynophora, Drepanolejeunea serricalyx, and D. tricornua. Significant range extensions within the bioregion are reported for another two species. Cololejeunea kapingaensis, previously reported as ramicolous, is here reported as an epiphyll.

Xylosma craynii W.E.Cooper is newly described from the Wet Tropics bioregion of north-eastern Queensland. The new species is illustrated and notes on habitat and distribution are provided.

Described by a leading Australian botanist as ‘Australia’s most competent bryologist’, David Meagher’s broad knowledge of Australian bryophytes was extraordinary. He was well-respected by bryologists around the world for his MSc research on the leafy liverwort genus Bazzania, and his PhD thesis on the bryophytes of Lord Howe Island. In the last twenty years, David published over 60 papers, most with him as the single author but several in collaboration with other Australian bryologists. He described twelve new species of Bazzania, including nine in Australia, two in Papua New Guinea and one in New Zealand. With colleagues he named two new moss species and reported several range extensions and new records in the Australian Wet Tropics. David’s fieldwork on flora and fauna extended to Tasmania, Victoria, New South Wales, Queensland, Lord Howe Island, the Kermadec Islands in the South Pacific, and the mid-west of the USA.

A new species of pitcher plant from rain forest on limestone karst in the Purari River catchment in the Gulf Province of Papua New Guinea is described and illustrated as Nepenthes calcicola Gary W.Wilson, S.Venter &amp; Damas. It is distinguished from N. neoguineensis on the basis of its distribution, ecology, habitat, and pitcher and inflorescence morphology. The new species is illustrated, and description is here given. The species is assessed as Vulnerable (VU) according to IUCN criteria.