Search

Circumscription of the large genus Pultenaea Sm. has been contentious since shortly after description. We draw on recently generated phylogenomic data to provide a fully resolved phylogeny of Pultenaea and related genera based on near-complete species level sampling for the genus. Phylogenomic data divide Pultenaea sens. lat. into five independent lineages, corresponding to previously identified clades, that we recognise as distinct genera. Pultenaea sens. str. contains most of the currently recognised species and as circumscribed here, all of the species are endemic to eastern Australia except for P. tenuifolia R.Br. & Sims that extends across the Nullarbor into Western Australia. The genus Euchilus R.Br. is reinstated for eight species, all endemic to south-west Western Australia except for E. elachistus (F.Muell.) R.L.Barrett & Orthia that also occurs in South Australia. Three new genera are described, with all of the constituent species endemic to south-west Western Australia: Grievea R.L.Barrett, Clugston & Orthia, with two species, Jennata R.L.Barrett, Clugston & Orthia, with nine species and Loricobbia R.L.Barrett, Clugston & Orthia with six species. Pultenaea adunca Turcz. remains unplaced but we exclude this species from our concept of Pultenaea. Twenty-one new combinations are made: Euchilus aridus (E.Pritz.) R.L.Barrett & Orthia, E. calycinus subsp. proxenus (Orthia & Chappill) Orthia & R.L.Barrett, E. daena (Orthia & Chappill) Orthia & R.L.Barrett, E. elachistus (F.Muell.) R.L.Barrett & Orthia, Grievea brachytropis (Benth. ex Lindl.) R.L.Barrett & Orthia, G. craigiana (C.F.Wilkins, Orthia & Crisp) Orthia & R.L.Barrett, Jennata brachyphylla (Turcz.) R.L.Barrett & Clugston, J. empetrifolia (Meisn.) R.L.Barrett & Clugston, J. ericifolia (Benth.) R.L.Barrett & Clugston, J. indira (Orthia & Crisp) Orthia & R.L.Barrett, J. indira subsp. monstrosita (Orthia) Orthia & R.L.Barrett, J. indira subsp. pudoides (Orthia) Orthia & R.L.Barrett, J. radiata (H.B.Will.) R.L.Barrett & Clugston, J. strobilifera (Meisn.) R.L.Barrett & Clugston, J. verruculosa (Turcz.) R.L.Barrett & Clugston, Loricobbia aspalathoides (Meisn.) R.L.Barrett & T.D.Macfarl., L. ochreata (Meisn.) R.L.Barrett & T.D.Macfarl., L. pauciflora (M.B.Scott) R.L.Barrett & T.D.Macfarl., L. pinifolia (Meisn.) R.L.Barrett & T.D.Macfarl., L. reticulata (Sm.) R.L.Barrett & T.D.Macfarl. and L. skinneri (F.Muell.) R.L.Barrett & T.D.Macfarl. The bush-pea genus (Pultenaea) is one of the larger legume genera in Australia but has been difficult to define. We present a new classification of the group, recognising five genera instead of one using a large DNA based analysis of relationships. Three genera are newly described and one genus is reinstated, and these are almost entirely restricted to south-west Western Australia, with true Pultenaea being mostly restricted to eastern Australia. (Photograph by Russell Barrett.) This article belongs to the collection Genomics for Australian Plants. [ABSTRACT FROM AUTHOR]

A taxonomic revision of the Pultenaea setulosa species complex (Fabaceae, tribe Mirbelieae) is presented. Prior to this study, P. setulosa Benth. was broadly circumscribed as a single, morphologically variable species. Here, we present evidence supporting the recognition of 18 species, 14 of which are new to science. Pultenaea setulosa is recircumscribed as a morphologically uniform taxon endemic to the Marlborough region in south-east Queensland. We reinstate Pultenaea boormanii H.B.Will., Pultenaea campbellii Maiden & Betche and Pultenaea lapidosa Corrick from synonymy of P. setulosa and describe an additional 14 new species: Pultenaea acanthocalyx R.L.Barrett & Clugston, Pultenaea corrickiae R.L.Barrett, Orme & Clugston, Pultenaea estelleae R.L.Barrett & Clugston, Pultenaea farmeriana R.L.Barrett, Orme & P.H.Weston, Pultenaea hoskingii R.L.Barrett & Clugston, Pultenaea imminuta R.L.Barrett & S.F.McCune, Pultenaea murrayi R.L.Barrett, Pultenaea palssoniae R.L.Barrett & Clugston, Pultenaea praetermissa R.L.Barrett & Albr., Pultenaea purdieae R.L.Barrett & Clugston, Pultenaea renneri R.L.Barrett & Clugston, Pultenaea venusta R.L.Barrett & Orme, Pultenaea westonii R.L.Barrett & Clugston and Pultenaea woolcockiorum R.L.Barrett & Clugston. Sixteen of these species are endemic to New South Wales, one to Queensland and one to Victoria. All taxa are described and illustrated, and habitats and conservation status are discussed. Two additional related species, Pultenaea procumbens A.Cunn. and P. setigera A.Cunn. ex Benth. are recircumscribed. Pultenaea setigera is reinstated here, known from the type collection made in 1822 and is possibly extinct. Lectotypes are selected for the names Pultenaea boormanii, P. campbellii, P. procumbens, P. setigera and P. setulosa. [ABSTRACT FROM AUTHOR]

Morphological and single-nucleotide polymorphism data support splitting Pultenaea glabra Benth. into eight species, including one in Victoria, and seven in eastern and northern New South Wales. Six species are newly described, five of which are, like P. glabra , narrow-range endemics within the Greater Blue Mountains World Heritage Area and adjacent sandstone landforms of the Great Dividing Range. The recognition of six new species from what was broadly P. glabra has implications for conservation management, including for P. glabra itself, which has a smaller distribution and more precise habitat requirements than previously thought. One of the new species, P. percussa , is known by a single 1971 gathering only. The occurrence of several narrow-range Blue Mountains endemic Pultenaea species may be explained by the combination of edaphic diversity and topographic complexity, which could act in concert to promote divergences among small, allopatric populations. Hybrids between P. glabra and P. flexilis Sm. are documented for the first time; however, limited evidence for introgression between the two species was observed. The following new taxa are described: Pultenaea aculeata M.A.M.Renner, P.H.Weston & S.Clarke, Pultenaea percussa M.A.M.Renner & P.H.Weston, Pultenaea furcata M.A.M.Renner & R.L.Barrett, Pultenaea mutabilis M.A.M.Renner & P.H.Weston, Pultenaea mutabilis var. angusta M.A.M.Renner, P.H.Weston, & S.Clarke, Pultenaea praecipua M.A.M.Renner & P.H.Weston, Pultenaea praecipua subsp. temperata M.A.M.Renner & R.L.Barrett, and Pultenaea tenebrosa M.A.M.Renner, P.H.Weston & S.Clarke. Lectotypes are designated for Pultenaea villosa var. glabrescens Benth. and Pultenaea weindorferi Reader. The threatened plant Pultenaea glabra is actually a complex of eight species, six of which are new to science. Pultenaea glabra is less common than previously thought, and five of the six new species are also rare and likely threatened, some critically so. This study has significant implications for the conservation of unique flora of the upper Blue Mountains and surrounding country. [ABSTRACT FROM AUTHOR]

Aim We tested whether the divergence of South American and Australian Lomatia was the result of the breakup of Gondwana, and assessed the date of divergence between Tasmania and mainland Australia, and across the Hunter River Valley. Location South America (Chile and Argentina) and eastern Australia (Tasmania, Victoria, New South Wales and Queensland). Methods We sequenced one chloroplast (psbA-trnH intergenic spacer) and two nuclear (PHYA and ITS) markers across all 12 species of Lomatia, five species of Telopea and Embothrium coccineum, and included sequences from Gen- Bank for the rest of the tribe Embothrieae. Species relationships were inferred using Bayesian and maximum likelihood analyses, then divergence times estimated using the random local clock in BEAST. Results The chronogram is congruent with geological events: SAm (SAm (SAm (Tas (NEQld (SEAus north of the Hunter + SEAus south of the Hunter))))). South American and Australian species of Lomatia diverged between 35 and 64 Ma. Tasmanian species of Lomatia diverged from mainland Australian taxa c. 32 Ma. Mainland Australian species of Lomatia are mostly not corroborated as monophyletic but show a divergence either side of the Hunter River Valley, dated at 17 Ma. Main conclusions The divergence date between South American Lomatia ferruginea and Australian species cannot exclude Gondwanan vicariance; however, divergences within South America occurred prior to separation of South America and Australia from Antarctica. Tasmanian species diverged from mainland Australia in the early Oligocene. Mainland Australian species of Lomatia are not resolved but form two clades representing populations north and south of the Hunter River Valley, confirming the Hunter River Valley as a significant barrier to gene flow for plants. We suggest that drying events that divided northern and southern floras at the Hunter River Valley occurred at the same time as those that divided eastern and western floras. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Subtribe Hakeinae (526 spp.) represents a large Australian plant radiation central to our understanding of that flora's evolution and ecology. It contains Grevillea--the third largest plant genus in Australia and a group inferred to have among the highest diversification rates in the angiosperms. However, we lack a robust phylogenetic framework for understanding subtribe Hakeinae and recognize that Grevillea lacks an unambiguous synapomorphy supporting its monophyly. METHODS: We used four plastid and one nuclear DNA region from a taxonomically even sampling of a third of the species to infer a time-calibrated phylogeny of Hakeinae and absolute diversification rates of major clades. We developed the R package addTaxa to add unsampled taxa to the tree for diversification rate inference. KEY RESULTS: Grevillea is paraphyletic with respect to Hakea and Finschia. Under most parameter combinations, Hakea contains the major clade with the highest diversification rate in Hakeinae, rather than Grevillea. The crown age of the Grevillea+Hakea+Finschia crown group is about double that of prior estimates. CONCLUSIONS: We demonstrate that the paraphyly of Grevillea considerably enlarges the number of Australian descendants from its most recent common ancestor but has also misled investigators who considered a single operational taxonomic unit as adequate to represent the genus for inferences of diversification rate and timing. Our time-calibrated phylogeny can form the basis of future evolutionary, comparative ecology, and biogeography studies involving this large Australian plant radiation, as well as nomenclatural changes. [ABSTRACT FROM AUTHOR]

Premise of study: Have Gondwanan rainforest floral associations survived? Where do they occur today? Have they survived continuously in particular locations? How significant is their living floristic signal? We revisit these classic questions in light of significant recent increases in relevant paleobotanical data. • Methods: We traced the extinction and persistence of lineages and associations through the past across four now separated regions-Australia, New Zealand, Patagonia, and Antarctica-using fossil occurrence data from 63 well-dated Gondwanan rainforest sites and 396 constituent taxa. Fossil sites were allocated tofour age groups: Cretaceous, Paleocene-Eocene, Neo-gene plus Oligocene, and Pleistocene. We compared the modern and ancient distributions of lineages represented in the fossil record to see if dissimilarity increased with time. We quantified similarity-dissimilarity of composition and taxonomic structure among fossil assemblages, and between fossil and modern assemblages. • Key results: Strong similarities between ancient Patagonia and Australia confirmed shared Gondwanan rainforest history, but more of the lineages persisted in Australia. Samples of ancient Australia grouped with the extant floras of Australia, New Guinea, New Caledonia, Fiji, and Mt. Kinabalu. Decreasing similarity through time among the regional floras of Antarctica, Patagonia, New Zealand, and southern Australia reflects multiple extinction events. • Conclusions: Gondwanan rainforest lineages contribute significantly to modern rainforest community assembly and often co-occur in widely separated assemblages far from their early fossil records. Understanding how and where lineages from ancient Gondwanan assemblages co-occur today has implications for the conservation of global rainforest vegetation, including in the Old World tropics. [ABSTRACT FROM AUTHOR]

Background and Aims When species cohesion is maintained despite ongoing natural hybridization, many questions are raised about the evolutionary processes operating in the species complex. This study examined the extensive natural hybridization between the Australian native shrubs Lomatia myricoides and L. silaifolia (Proteaceae). These species exhibit striking differences in morphology and ecological preferences, exceeding those found in most studies of hybridization to date. Methods Nuclear microsatellite markers (nSSRs), genotyping methods and morphometric analyses were used to uncover patterns of hybridization and the role of gene flow in morphological differentiation between sympatric species. Key Results The complexity of hybridization patterns differed markedly between sites, however, signals of introgression were present at all sites. One site provided evidence of a large hybrid swarm and the likely presence of multiple hybrid generations and backcrosses, another site a handful of early generational hybrids and a third site only traces of admixture from a past hybridization event. The presence of cryptic hybrids and a pattern of morphological bimodality amongst hybrids often disguised the extent of underlying genetic admixture. Conclusions Distinct parental habitats and phenotypes are expected to form barriers that contribute to the rapid reversion of hybrid populations to their parental character state, due to limited opportunities for hybrid/intermediate advantage. Furthermore, strong genomic filters may facilitate continued gene flow between species without the danger of assimilation. Stochastic fire events facilitate temporal phenological isolation between species and may partly explain the bi-directional and site-specific patterns of hybridization observed. Furthermore, the findings suggest that F1 hybrids are rare, and backcrosses may occur rapidly following these initial hybridization events. [ABSTRACT FROM PUBLISHER]

* Premise of the study: The glacial cycles of the Quaternary did not impact Australia in the same way as Europe and North America. Here we investigate the history of population isolation, species differentiation, and hybridization in the southeastern Australian landscape, using five species of Lomatia (Proteaceae). We use a chloroplast DNA phylogeography to assess chloroplast haplotype (chlorotype) sharing among these species and whether species with shared distributions have been affected by shared biogeographic barriers. * Methods: We used six chloroplast DNA simple sequence repeats (cpSSR) across five species of Lomatia, sampled across their entire distributional range in southeastern Australia. Resulting size data were combined, presented as a network, and visualized on a map. Biogeographical barriers were tested using AMOVA. To explore hypotheses of chlorotype origin, we converted the network into a cladogram and reconciled with all possible species trees using parsimony-based tree mapping. * Key results: Some chlorotypes were shared across multiple species of Lomatia in the study, including between morphologically differentiated species. Chlorotypes were either widespread in distribution or geographically restricted to specific regions. Biogeographical structure was identified across the range of Lomatia. The most parsimonious reconciled tree incorporated horizontal transfer of chlorotypes. * Conclusions: Lomatia shows evidence of both incomplete lineage sorting and extensive hybridization between co-occurring species. Although the species in the study appear to have responded to a number of biogeographic barriers to varying degrees, our findings identified the Hunter River Valley as the most important long-term biogeographic barrier for the genus in south eastern Australia. [ABSTRACT FROM AUTHOR]