Australian Systematic Botany

Published by CSIRO Publishing
Online ISSN: 1030-1887
Publications
Article
The morphology and development of flowers and pseudanthia of Calycopeplus paucifolius are described in detail in the context of recent molecular phylogenies of the tribe Euphorbieae and a recent comparative developmental analysis of other taxa within this tribe. Calycopeplus resembles subtribes Neoguillauminiinae and Anthosteminae in some respects (dichasial formation of male flowers within male partial inflorescences, late formation of a constriction in male and female flowers and early formation of a female perianth), but resembles Dichostemma (subtribe Anthosteminae) in possessing only four male partial inflorescences. Calycopeplus and all other Euphorbieae possess only three carpels, except Dichostemma, which has four carpels per female flower. The studied species differs from the closely related Neoguillauminia cleopatra (subtribe Neoguillauminiinae) in that only four nectaries are formed, situated on the rim of the cuplike involucre (in Neoguillauminia 8-10 nectaries arise directly from the base of the pseudanthium). In contrast to all other studied Euphorbieae with trimerous gynoecia, the unpaired carpel of C. paucifolius is oriented in an upper/adaxial position (it lies in the lower/abaxial position in all other studied taxa). On the basis of these results we discuss possible pathways of cyathium evolution and the role of the cyathium as a possible key innovation within Euphorbieae.'Calycopeplus is as perfect an example of a connecting link as a morphologist may wish for.' (Croizat 1937, p. 404).
 
Daily patterns of nectar secretion in Acacia senegal in Mkomazi Game reserve, Tanzania (Stone et al. 1998). Nectar was sampled from one individual on 21 December 1995, sampling 10 flower heads per datum. (A) Mean nectar volume per flower. (B) Mean nectar concentration (% sucrose by mass). Values are means ± 1 standard error. 
Daily patterns of floral reward availability in the Mkomazi Acacia species (Stone et al. 1998) Values given for each variable indicate the ranges within species observed across days, sites and years. Relative humidity at dehiscence represents the mean value over the period between onset of pollen release and maximum availability 
Patterns of pollen availability through time for individual trees of Acacia nilotica, A. tortilis, A. zanzibarica, A. drepanolobium and A. senegal in the Mkomazi Game Reserve, Tanzania. Each symbol represents an individual tree. Pollen release is scored as described for Fig. 3. 
Article
We review the pollination ecology of acacias worldwide, dicsussing (1) the rewards provided to flower visitors, (2) the temporal patterns of flowering and reward provision and (3) the taxonomic composition of flower visitor assemblages. The flowers of most acacias (including all members of the subgenus Phyllodinae) offer only pollen to flower visitors and floral nectar is limited to a minority of species in the subgenera Acacia and Aculeiferum. The most important pollinators of acacias are social and solitary bees, although other insects and nectar-feeding birds are important in specific cases. Acacias that secrete nectar attract far more species-rich assemblages of flower-visitors, although many of these are probably not important as pollinators. Most acacias in the subgenus Phyllodinae have long-lived protogynous flowers, without clear daily patterns in reward provision and visitation. In contrast, most members of the other two subgenera have flowers that last for a single day, appear to be protandrous and have clear daily patterning in reward provision and visitation. The generality of these patterns should not be assumed until the pollination ecology of many more phyllodinous acacias has been studied, particularly in arid environments. The accessibility of the floral rewards in acacia flowers makes them important examples of two general issues in plant communities - the partitioning of shared pollinators and the evolution of floral ant repellents.
 
Data on measured and counted characters for Sporolithon durum Extreme values are given in parentheses. TS = tetrasporangial sorus; MC = male conceptacle; FC = mature female-carposporangial conceptacle. Maximum values are those determined from herbarium material and may not reflect true maxima for the species
Article
Sporolithon (Sporolithaceae, Corallinales) is represented in southern Australia by S. durum (Foslie) Townsend et Woelkerling, comb. nov. The species and the development of male and female-carposporangial conceptacles and tetrasporangial compartments and sori are described in detail for the first time. Information on etymology, collections examined, distribution, seasonality and habit and comparisons with other species is also included. Published records of S. erythraeum from southern Australia have not been substantiated. Two further species have been reported under the generic name Archaeolithothamnion. Archaeolithothamnion australasicum is a species of uncertain status, while A. mirabile is conspecific with Lithothamnion muelleri Lenorrnand ex Rosanoff. Differences between the Sporolithaceae and the Corallinaceae, and the delimitation of genera within the Sporolithaceae, are reconsidered in relation to new data on S. durum. The Sporolithaceae is characterised by tetrasporangia that produce cruciately arranged spores and develop within calcified sporangial compartments, while the Corallinaceae is characterised by tetrasporangia that produce zonately arranged spores that do not develop in calcified sporangial compartments. Two genera of Sporolithaceae are recognised: Heydrichia, in which tetrasporangial compartments are enclosed by modified filaments to form sporangial complexes; and Sporolithon, in which tetrasporangial compartments are not enclosed by modified filaments and sporangial complexes are absent. The concepts of conceptacle and sorus also are reconsidered.
 
Distribution map of (a) Ptilotus exaltatus var. exaltatus: Map CANB collections id: 23437 and (b) Ptilotus nobilis var. nobilis; Map CANB collections id: 24924 (Source: Australian Plant Name Index, dated March 2006). Dots indicate locations where plants occur.  
Intra-specific comparison of morphological characteristics for Ptilotus exaltatus and Ptilotus nobilis complexes
Phylogenetic tree (Neighbour-Joining) of 14 species of Ptilotus and the outgroup taxon, Gomphrena celosioides based on Tamura and Nei (1993) model. Scale bar represents genetic distance. Numbers indicate bootstrap test values based on 1000 replicates.
Phylogenetic tree (UPGMA) of 14 species of Ptilotus and the outgroup taxon, Gomphrena celosioides based on Tamura and Nei (1993) model. Scale bar represents genetic distance. Numbers indicate bootstrap test values based on 1000 replicates.
Article
A complete botanical key for the genus Ptilotus R. Brown ( family Amarathaceae) has not yet been published. Identifying the 100 or more Ptilotus species using morphological characters has been difficult because plants often exhibit slight morphological differences and intermediate characteristics common to several species, subspecies, varieties and forms. Ptilotus exaltatus Nees and P. nobilis ( Lindl) F. Muell share many morphological characteristics, but are classified as different species predominantly based on inflorescence colour. The current study involved a molecular phylogenetic analysis of 14 Ptilotus species using sequence data from the internal transcribed spacer ( ITS) regions ITS 1 and ITS 2 within the 18S-26S nuclear rDNA. Of the 39 accessions analysed, all except those identified as P. exaltatus and P. nobilis clustered according to their respective species based on their morphological taxonomy. In contrast, all 18 P. exaltatus and P. nobilis accessions formed a distinct monophyletic clade with 99% bootstrap values and a low level of sequence variation ( GD=0.002). Taking into account the lack of reliable morphological characters for separating P. exaltatus and P. nobilis, together with the ITS sequence data showing little genetic divergence or genetic structure, we propose that P. exaltatus and P. nobilis are conspecific.
 
Natural distributions () and germplasm sample provenances () of (A) Cassia brewsteri (30 accessions), (B) C. tomentella (three accessions), (C) C. marksiana (one accession) and (D) C. queenslandica (one accession).  
Cassia accessions studied N, northern provenance; S, southern provenance; L, Longdale site; m, maternal leaf tissue alphanumeric designations identify the collection site and tree
Comparison of Australian Cassia species, by using modified Randomly Amplified DNA Fingerprints (RAFs) with primer ABI-06. Only part of the autoradiogram is shown, C. brewsteri accession 67E was used as an internal standard.  
Multidimensional scaling (MDS) ordination plot of the genetic similarities between 35 Australian Cassia accessions on the basis of 265 Randomly Amplified DNA Fingerprint (RAF) polymorphisms generated with three primers. Alienation of final configuration = 0.09067, proportion of variance (RSQ) = 0.99025.  
Article
Genetic diversity in Cassia brewsteri (F. Muell.) F. Muell. ex Benth. was assessed with Randomly Amplified DNA Fingerprints (RAFs). Thirty accessions of C. brewsteri collected from throughout its natural distribution were analysed with three random decamer primers, along with three accessions of C. tomentella (Benth.) Domin and a single accession of each of C. queenslandica C. T. White and C. marksiana (F. M. Bailey) Domin. The three primers yielded a reproducible amplification profile of 265 scorable polymorphic fragments for the 35 accessions. These molecular markers were used to calculate Nei and Li similarity coefficients between each pair of individuals. A matrix of dissimilarity of each pair of individuals was examined by multidimensional scaling (MDS). The analysis supports the division of C. brewsteri into two subspecies and the suggestion that intergradation of C. brewsteri and C. tomentella can occur where the distributions of these species meet.
 
Article
Three new species of Cuvularia, C. bothriochloae sp. nov., C. micrairae sp. nov. and C.queenslandica sp. nov., isolated from grass hosts in Queensland are described, illustrated and compared with closely related species.
 
Article
This study represents the first comprehensive analysis of phylogenetic relationships within the Australian water-lilies, Nymphaea subg. Anecphya. Our 51-accession dataset covers all 10 species of the subgenus, except the newly described N. alexii, and includes information from the nuclear ITS as well as from the chloroplast trnT-trnF region. The results show that molecular data are consistent with morphology, because the subdivision of subg. Anecphya into two major clades, a large-seeded and a small-seeded group, could be confirmed. Within the large-seeded group, Nymphaea atrans and N. immutabilis seem to form one clade, whereas samples of N. gigantea, N. georginae, N. macrosperma and N. carpentariae form another. Relationships within the small-seeded group, containing all samples of N. violacea, N. elleniae and N. hastifolia, are less clear, since the trees obtained from the chloroplast and the nuclear marker are incongruent. The samples of N. violacea do not form a monophyletic group in each of the trees, but-at least in the ITS tree-group with either N. elleniae or N. hastifolia/Ondinea, respectively. Polymorphisms among ITS paralogues, i.e. substitutions at single nucleotide positions and length polymorphisms, have been observed in some samples of N. violacea. This fact as well as the incongruent phylogenetic signal obtained from the chloroplast and the nuclear genomes point to recent hybridisation or introgression in this group. Remarkably, Ondinea purpurea is resolved within the small-seeded group by both markers and seems to have a close relationship to N. hastifolia. Although incomplete lineage sorting cannot be fully excluded to explain high variability in N. violacea, molecular data potentially hint to a case of still imperfect taxonomy.
 
Natural location, number of trees sampled and seedlot numbers for red mahoganies used for the study
Ancestry assignment for 86 individuals in the Pellita genetic group using a K = 2 model. Individuals are ordered according to the scheme described for Fig. 2; numbers on the x-axis correspond to: Eucalyptus resinifera (1, Woolgoolga; 2, Coffs Harbour) and E. pellita (3, Bupul Muting, Indonisea; 4, S of Kirowo, PNG; 5, Serira, PNG; 6, Kiriwo, PNG; 7, Goe, PNG; 8, Helenvale, Qld; 9, Starcke Stn, Qld; 10, Mossman, Qld; 11, NW Kuranda, Qld; 12, El Arish, Qld; 13, Kirrama Range, Qld; 14, S Cardwell, Qld; 15, SSO, Melville Is. NT). Localities without state or country details are NSW, Australia. 
Ancestry assignment for 44 individuals in the Queensland Eucalyptus pellita group determined using STRUCTURE with a K = 2 model. Labels on x-axis correspond to localities as follows; E. resinifera (1, Woolgoolga; 2, Coffs Harbour) and E. pellita (3, Helenvale, Qld; 4, Starcke Stn, Qld; 5, Mossman, Qld; 6, NW Kuranda, Qld; 7, El Arish, Qld; 8, Kirrama Range, Qld; 9, S Cardwell, Qld). Localities without state or country details are NSW, Australia. 
Unrooted consensus neighbour-joining tree for six genetic groups based on DA (Nei's distance). Percentage support for 1000 bootstrapped trees is given at nodes. See Table 3 for explanation of the group label. 
Article
The red mahogany group (Eucalyptus ser. Annulares Blakely) includes some of the most important commercial species (i.e. Eucalyptus urophylla S.T.Blake) worldwide for forestry in the subtropics and tropics. However, the taxonomic status of some species in this group is unclear and the relationship among and genetic structuring within some species is unresolved. The present study examined genetic variation at 13 microsatellite loci in E. pellita F.Muell., E. resinifera Smith and E. scias L.Johnson & K.Hill. Despite close geographical proximity and natural hybridisation in northern Queensland, E. resinifera and E. pellita remain genetically distinct as taxa. Within E. pellita, two genetic groups were clearly resolved, one from New Guinea and one from Queensland (Cape York Peninsula populations were not sampled). Geographic structuring was also evident in E. resinifera, with northern Queensland populations separating from those from Fraser Island southwards. Ecological factors and species disjunctions were implicated in the genetic substructuring of these two taxa because patterns of geographic variation aligned with biogeographical regions. E. scias was indistinguishable from southern E. resinifera and its three subspecies could not be resolved.
 
Article
Palaeofloristic studies of the Antarctic Peninsula region are important in furthering our understanding of (i) the radiation and rise to ecological dominance of the angiosperms in the Southern Hemisphere during the Late Cretaceous and (ii) the present day disjunct austral vegetation. Investigations of Upper Cretaceous and Early Tertiary sediments of this region yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood which provides evidence for the existence, since the Late Cretaceous, of temperate forests similar in composition to those found in present-day southern South America, New Zealand and Australia. This paper describes two previously unrecognised morphotypes, which can be assigned to the Monimiaceae sensu lato, and represents the first record of this family in the wood flora of Antarctica. Specimens belonging to the first fossil morphotype have been assigned to Hedycaryoxylon SÜss (subfamily Monimioideae) because they exhibit anatomical features characteristic of Hedycaryoxylon and extant Hedycarya J.R.Forst. & G.Forst. and Tambourissa Sonn. Characters include diffuse porosity, vessels which are mainly solitary with scalariform perforation plates, opposite to scalariform intervascular pitting, paratracheal parenchyma, septate fibres and tall (>3 mm), wide multiseriate rays with a length: breadth ratio of approximately 1: 4. Specimens belonging to the second morphotype have been assigned to Atherospermoxylon KrÄusel, erected for fossil woods of the Monimiaceae in the tribe Atherospermeae (now Atherospermataceae) in that they exhibit anatomical features similar to Atherospermoxylon and extant Daphnandra Benth., Doryphora Endl. and Laurelia novae-zelandiae A.Cunn. These characters include diffuse to semi-ring porosity, scalariform perforation plates with up to 25 bars, septate fibres, relatively short (<1 mm) rays with a length: breadth ratio of between 1: 4 and 1: 11.
 
Article
A morphometric study was undertaken into alpine and subalpine species of Euchiton Cass. (Gnaphalieae: Asteraceae) in the Euchiton traversii species complex in south-eastern Australia and New Zealand. Phenetic analysis of both field-collected and herbarium specimens resolved the following six taxa included: Euchiton traversii (Hook.f.) Holub, Euchiton argentifolius (N.A.Wakef.) Anderb., Euchiton lateralis (C.J.Webb) Breitw. & J.M.Ward, Argyrotegium mackayi (Buchanan) J.M.Ward & Breitw., Argyrotegium fordianum (M.Gray) J.M.Ward & Breitw. and Argyrotegium poliochlorum (N.G.Walsh) J.M.Ward & Breitw. The results support the segregation of the genus Argyrotegium J.M.Ward & Breitw. from Euchiton. E. argentifolius is distinct from E. traversii, but conspecific with A. mackayi. E. lateralis is present in Tasmania as well as New Zealand. The distribution of Australian E. traversii is redefined to mainland alpine regions with a few rare occurrences in Tasmania. Australian E. traversii was shown to be similar to its New Zealand counterparts. Differences between E. lateralis and E. traversii were clarified. A. fordianum and A. poliochlorum are distinct species and their transfer to Argyrotegium is supported.
 
Descriptions and codes for numeric (a), coefficient (b) and multistate (c) attributes used in this study of Avicennia in Australasia
Article
Morphological variation in flowers, fruit and leaves of five Australasian species of Avicennia was assessed using multivariate techniques. Groupings based on 184 herbarium specimens gathered throughout the region showed no intermediates or potential hybrids between species, A. alba, A. integra, A. rumphiana (=A. lanata), A. marina (=A. eucalyptifolia; =A. balanophora) and A. officinalis. The most common and systematically troublesome species, A. marina, was considered further in a regional litter fall survey of 25 Australian sites, and in a detailed field study of eight locations within one estuary. In both studies, morphological variation correlated with environmental factors including air temperature, rainfall, intertidal position and upriver location. Major differences were also observed within individuals, as shown in sun and shade leaves. These observations suggested that many attributes, especially of leaves, were influenced by environmental factors, demonstrating their unsuitability in earlier systematic treatments. Other attributes reflecting putative subspecific genetic variation, included bark character, extent of pubescence on calyx lobes, and stigma position in relation to anthers. These characterise three groupings of A. marina sites, related to major biogeographic zones within this region: southeastern Australia and New Zealand; northern and north-eastern Australia and southern Papua New Guinea; and south-western Australia.
 
Article
In Australasia (including Australia, New Zealand, New Guinea and other islands in the south-western Pacific) the mangrove genus Avicennia L. consists of five species: A. alba Bl., A. integra N. C. Duke, A. marina (Forsk.) Vierh., A. officinalis L. and A. rumphiana Hallier f. Based on morphological characters and supported by allele patterns in isozyme studies (reported elsewhere), A. marina is divided into three varieties. Keys, descriptions, brief synonymy, descriptive figures and distribution maps are provided for each of the seven taxa.
 
Article
Over the last two decades, CSIRO surveys of the seagrass communities in the south-western Gulf of Carpentaria and at Groote Eylandt, the Northern Territory, have provided opportunities for the collection of marine macroalgae from this poorly explored, remote region. Although the cruises did not concentrate on macroalgal communities which typically grow on rocky substrates, 64 specific and subspecific taxa of marine Chlorophyta, Phaeophyceae and Rhodophyta were collected, including 30 species newly recorded for the Gulf. The majority of Gulf species also occur on the tropical eastern Australian coast. one hundred and thirteen macroalgal taxa are now known to occur in the Gulf of Carpentaria, the number from the present study supplemented by collections from the 1948 Arnhem Land Expedition and from an ethnobiological study on Groote Eylandt during the 1970s. Twelve species are recorded by all three Gulf studies and 23 species are reported by two studies. The relatively low number of species common to more than one study is thought to result from each study's narrow sampling window which fails to adequately document the considerable spatial and temporal variability of macroalgal species. Accordingly, the number of species presently recorded for the Gulf is considered to be an underestimate of macroalgal biodiversity for the region. It is clear that further detailed taxonomic and ecological investigations are urgently required before the full extent of macroalgal biodiversity in tropical Australia can be appreciated.
 
Article
The putative hybrid tree taxon, Sonneratia alba x 3. lanceolata, previously reported for two incomplete herbarium specimens from northern Australia and south-east West Irian, has since been observed and collected in mangrove forests of southern Papua New Guinea. It is morphologically uniform and is described as S. xurama. Notes on its floral phenology, distribution and ecology are given, including a key to all major Sonnevatia taxa in this region.
 
Article
Mid-Cretaceous (latest Albian-earliest Cenomanian) sediment in seven bore cores from the Eromanga Basin (south-western Queensland) was sampled for organically preserved plant macrofossils. Among those recovered, 26 taxa of conifers have been distinguished. Families Araucariaceae, Podocarpaceae, and Cheirolepidiaceae were prominent. The Araucariaceae include Araucaria sp., while the remainder are considered to represent extinct genera. Podocarpaceae are all species of extinct genera and two new genera are described: Eromangia and Thargomindia. There are two species of Cheirolepidiaceae. One of these, Geinitzea tetragona Cantrill & Douglas, is made the type of a new genus, Otwayia, with two species, O. tetragona and O. cudgeloides, both occurring in the Eromanga Basin. No unequivocal Cupressaceae/Taxodiaceae were recognised.
 
Article
This taxon was recognised in Australian mangrove assemblages as Avicennia officinalis L., which is commonly found in Indo-Malesia and southern New Guinea. However, it is morphologically distinct, and the major distinguishing character of entire margins for calyx and bracts is unique in the genus. This species, described here as A. integra, occurs only in the Northern Territory of Australia. It therefore has the dual distinction for an Australian mangrove species of not only being endemic, but also being absent from the floristically rich tidal forests of north-eastern Queensland. Notes on its floral phenology, distribution and ecology are also given.
 
Article
Eleven species of Dictyopteris are recognised for Australia. The tropical species D. australis (Sonder) Askenasy, D. deliculata Lamouroux, D. plagiogramma (Montagne) Vickers, D. repens (Okamura) Borgesen, D. serrata (Areschoug) Hoyt and D. woodwardia (R. Brown ex Turner) C. Agardh are recorded for warmer coasts, although isolated populations of D. australis occur in the Gulfs region of South Australia. Dictyopteris acrostichoides (J. Agardh) Bornet and D. crassinervia (Zanardini) Schmidt are endemic to eastern Australia, with D. acrostichoides also extending to the eastern end of the southern coast. Dictyopteris gracilis Womersley and D. muelleri (Sonder) Reinbold occur on temperate southwestern and southern coasts. The west coast species Dictyopteris secundispiralis J. A. Phillips sp. nov. is described, and D. nigricans Womersley is reduced to a taxonomic synonym of D. muelleri. Detailed comparative studies undertaken on these species have identified several new taxonomically-informative characters useful for generic circumscription and species discrimination. Thallus branches which have a cortical layer composed of large cuboidal cells and reproductive organs scattered in fertile zones are additional characters which characterise the genus. Australian species of Dictyopteris are now well defined by differences in several distinctive vegetative and reproductive characters such as thallus morphology, blade cell layer number, structure of the thallus apex, presence of marginal teeth and lateral veins, distribution and structure of hair bundles, sporangia, oogonia and antheridial sori.
 
Article
Phylogenies inferred from both chloroplast and nuclear DNA regions have placed the south-west Australian genus Dryandra R. Br. ( 93 spp.) among the descendents of the most recent common ancestor of the more widespread Australian genus Banksia L. f. ( 80 spp.). Here we consider the alternative solutions to maintaining monophyly at the generic rank and choose to make new combinations and replacement names for Dryandra in Banksia. We make the new combination Banksia ser. Dryandra in Banksia subgen. Banksia for 108 of the 109 new combinations at the ranks of species, subspecies, and variety and all 18 of the replacement names. We treat Banksia subgen. Banksia as the most inclusive clade that includes the type of Banksia ( B. serrata) but not B. integrifolia. We erect Banksia subgen. Spathulatae to accommodate the species in the most inclusive clade that includes B. integrifolia but not B. serrata. These two subgenera of Banksia are equivalent to the clades informally called /Cryptostomata and /Phanerostomata elsewhere. We treat one of the new combinations, Banksia subulata, as incertae sedis within Banksia subgen. Banksia.
 
Article
Fossil woods with greatest anatomical similarity to modern Nothofagaceae are traditionally assigned to the organ genus Nothofagoxylon Gothan. All fossil wood records of Nothofagoxylon were re-evaluated so that recently collected specimens from the Antarctica Peninsula region could be assigned to taxa within this organ genus. Widespread synonymy was found within the published records of Nothofagoxylon, so that of the 16 described species, only seven were retained. Six of these fossil species were found to be present in Antarctica. In undertaking this review, some lauraceous woods assigned to Laurinoxylon Schuster were found to be nothofagaceous. Temporal and spatial patterns of occurrence of the Nothofagoxylon wood type help support current views that the centre of origin of the Nothofagaceae was within the Antarctic Peninsula–South America region during the Campanian followed by radiation into the lower southern latitudes throughout the Tertiary.
 
Article
Phylogenetic hypotheses are presented for Pultenaea based on cpDNA (trnL-F and ndhF) and nrDNA ( ITS) sequence data. Pultenaea, as it is currently circumscribed, comprises six strongly supported lineages whose relationships with each other and 18 closely related genera are weak or conflicting among datasets. The lack of resolution among the six Pultenaea clades and their relatives appears to be the result of a rapid radiation, which is evident in molecular data from both the chloroplast and nuclear genomes. The molecular data provide no support for the monophyly of Pultenaea as it currently stands. Given these results, Pultenaea could split into many smaller genera. We prefer the taxonomically stable alternative of subsuming all 19 genera currently recognised in Pultenaea sensu lato (= the Mirbelia group) into an expanded concept of Pultenaea that would comprise similar to 470 species.
 
Article
Uppermost Cretaceous sediments from the Cretaceous Kaitangata Coal Mine and the Wangaloa coast (south of Dunedin, New Zealand) were investigated for dispersed plant macrofossils. The gymnosperms include two cycads (Macrozamia sp. and Pterostoma sp.), Ginkgo sp., three further possible ginkgophyte taxa, and ten conifer taxa. The conifers include two new conifer genera and species, Maikuku stephaniae and Ware riderensis, which are placed in the Taxodiaceae s.l., five forms which can be placed into pre-existing genera (Araucaria sp., Otakauia lanceolata, Kaia minuta, Kakahuia sp. 'Kai Point', and Paahake cf. P. papillatus), and three others which are not identified to genus (Araucariaceae gen. indet., cf. Dacrycarpus, and 'Wangaloa conifer'). There are also 13 types of angiosperm cuticle, including one in the Lauraceae, and one with affinities to Chloranthaceae and Monimiaceae. Sample heterogeneity as regards taxa present and their abundance suggests taxonomic heterogeneity in the original vegetation.
 
Phylogram of the Fabaceae tribes Mirbelieae and Bossiaeeae, with Pultenaea sens. lat. showing an explosive radiation-short basal nodes subtended by a long stem. Modified from Crisp and Cook (2003a, fig. 2). Numbers on branches are bootstrap scores. *50 ≤ BS ≤ 69. 
Phylogeny of Pultenaea sens. lat. (in part) estimated from ITS sequences (right) and trnL-F (left), modified from Crisp and Cook (2003b). Terminals are grouped according to current generic placement. Podolobium (highlighted by grey boxes) comprises two groups, each showing different sister taxon relationships in each tree. Numbers above branches are Bayesian posterior probabilities; below are bootstrap scores from maximum parsimony (asterisks indicate branches from the MP strict consensus tree with bootstrap < 50). Circles indicate well-supported nodes that conflict between trees. 
Article
Phylogenetic trees can provide a stable basis for a higher-level classification of organisms that reflects evolutionary relationships. However, some lineages have a complex evolutionary history that involves explosive radiation or hybridisation. Such histories have become increasingly apparent with the use of DNA sequence data for phylogeny estimation and explain, in part, past difficulties in producing stable morphology- based classifications for some groups. We illustrate this situation by using the example of tribe Mirbelieae ( Fabaceae), whose generic classification has been fraught for decades. In particular, we discuss a recent proposal to combine 19 of the 25 Mirbelieae genera into a single genus, Pultenaea sens. lat., and how we might find stable and consistent ways to squeeze something as complex as life into little boxes for our own convenience.
 
Bootstrap consensus tree of 64 MPTs generated from parsimony analysis. Bootstrapping performed with 1000 replicates. Values above nodes indicate bootstrap values.  
Semi-strict consensus tree of the same 64 maximally parsimonious trees generated from entire ITS data set. For each MPT, consistency index, CI = 0.94; retention index, RI = 0.98; homoplasy index, HI = 0.05; and tree length = 488. Numbers above the branch indicate the frequency of occurrence of that branch in all trees.  
Semi-strict consensus tree of 100 maximally parsimonious trees generated from ITS2 sequences. For each MPT, consistency index, CI = 0.95; retention index, RI = 0.98, homoplasy index, HI = 0.05 and tree length = 227. Numbers above the branches indicate the frequency of occurrence of that branch in all trees.  
Pairwise comparisons of nucleotide substitutions of the 18 ITS sequences of Sporobolus spp. 
Article
The entire internal transcribed spacer ( ITS) region, including the 5.8S subunit of the nuclear ribosomal DNA ( rDNA), was sequenced by direct double-stranded sequencing of polymerase chain reaction (PCR) amplified fragments. The study included 40 Sporobolus ( Family Poaceae, subfamily Chloridoideae) seed collections from 14 putative species ( all 11 species from the S. indicus complex and three Australian native species). These sequences, along with those from two out-group species [ Pennisetum alopecuroides ( L.) Spreng. and Heteropogon contortus ( L.) P. Beauv. ex Roemer & Schultes, Poaceae, subfamily Panicoideae], were analysed by the parsimony method (PAUP; version 4.0b4a) to infer phylogenetic relationships among these species. The length of the ITS1, 5.8S subunit and ITS2 region were 222, 164 and 218 base pairs ( bp), respectively, in all species of the S. indicus complex, except for the ITS2 region of S. diandrus P. Beauv. individuals, which was 217 bp long. Of the 624 characters included in the analysis, 245 ( 39.3%) of the 330 variable sites contained potential phylogenetic information. Differences in sequences among the members of the S. pyramidalis P. Beauv., S. natalensis (Steud.) Dur & Schinz and S. jacquemontii Kunth. collections were 0%, while differences ranged from 0 to 2% between these and other species of the complex. Similarly, differences in sequences among collections of S. laxus B. K. Simon, S. sessilis B. K. Simon, S. elongatus R. Br. and S. creber De Nardi were 0%, compared with differences of 1-2% between these four species and the rest of the complex. When comparing S. fertilis ( Steud.) Clayton and S. africanus (Poir.) Robyns & Tourney, differences between collections ranged from 0 to 1%. Parsimony analysis grouped all 11 species of the S. indicus complex together, indicating a monophyletic origin. For the entire data set, pair-wise distances among members of the S. indicus complex varied from 0.00 to 1.58%, compared with a range of 20.08-21.44% among species in the complex and the Australian native species studied. A strict consensus phylogenetic tree separated 11 species of the S. indicus complex into five major clades. The phylogeny, based on ITS sequences, was found to be congruent with an earlier study on the taxonomic relationship of the weedy Sporobolus grasses revealed from random amplified polymorphic DNA ( RAPD). However, this cladistic analysis of the complex was not in agreement with that created on past morphological analyses and therefore gives a new insight into the phylogeny of the S. indicus complex.
 
Article
lThe description of Phytophthora macrochlamydospora J.A.G. Irwin is emended, following further taxonomic studies with additional isolates of the organism. Phytophthora macrochlamydospora is a Group VI Phytophthora species, producing non-papillate sporangia, and sex organs in paired culture with Phytophthora cambivora (Petri) Buisman, A(1) mating type. Sex organs have never previously been described for P. macrochlamydospora, and this research has shown that P. cambivora A(1) induces selfing in P. macrochlamydospora. Antheridia of P. macrochlamydospora are always amphigynous. Phytophthora macrochlamydospora produces large (up to 90 mum), thick-walled chlamydospores that distinguish it from all other Group VI species.
 
Article
The Podocarpaceae are the most morphologically diverse of conifer families. A taxonomic trend has resulted in recognising this diversity via smaller generic groupings, including several monotypes. A phylogenetic assessment of the monotypic genera Sundacarpus and Manoao was conducted employing maximum parsimony the analysis of sequence data from 18S-ribosomal DNA from 34 gymnosperm taxa, including 29 Podocarpaceae. In resulting trees, there is high bootstrap support for Podocarpaceae, including Phyllocladus, but the order of deep branches within the family is equivocal. Prumnopitys (Sundacarpus) amara (Blume) de Laub. and four other Prumnopitys spp. comprise a clade with a bootstrap value of 100%, supporting the retention of Sundacarpus as a section of Prumnopitys. Lagarostrobos franklinii (Hook.f.) Quinn and L. (Manoao) colensoi (Hook.) Quinn comprise a clade with equivocal bootstrap support, echoing previous results from parsimony analysis of morphological data. A conservative approach (i.e. one avoiding unnecessary monotypes) favours the retention of L. colensoi in Lagarostrobos, pending further evidence of relationships within the group.
 
Article
In two recent papers in this journal a leading proponent of panbiogeography, Michael Heads, has continued his critique of long-distance dispersal and molecular clocks, and promotion of alternative geological and evolutionary ideas. An axiomatic rejection of long-distance dispersal, on the grounds that it has no explanatory power, informs these critiques. However, fundamental issues with panbiogeographic theory remain unaddressed. In particular, insurmountable problems for most biologists are created by the requirement for a widespread, often ancient ancestor from which vicariant taxa arose through orthogenesis, and rejection of a role for natural selection or environmental change in species formation. Heads also discusses events in New Zealand in the late 1980s and early 1990s and claims the reaction of the scientific establishment to panbiogeography resulted in two panbiogeographers losing tenured positions, and excluded, silenced or drove the rest into exile. This is a dramatic but misleading interpretation of what happened. The losses of positions were unconnected to science issues. That it is difficult to get panbiogeographic work funded or published in New Zealand is undoubtedly true, but this fate is shared by any work that seeks to overturn established evolutionary theory but provides no convincing evidence for doing so.
 
Article
Inter- and infraspecific relationships in Hymenophyton Dumort. were studied by sequencing of the cpDNA trnTUGU-trnLUAA 5′exon intergenic spacer, trnLUAA 5′exon and trnLUAA intron and nrDNA internal transcribed spacer 2 (ITS2), and by morphological examination of representative specimens. Based on the molecular data, four taxa were recognised, comprising (i) Australasian H. flabellatum (Labill.) Dumort. ex Trevis., (ii) Chilean specimens, (iii) New Zealand H. leptopodum (Hook.f. & Taylor) A.Evans samples and (iv) a Tasmanian H. leptopodum specimen, respectively. The former three clades are supported by high bootstrap values, while the affinities of the latter specimen remain ambiguous in the calculated trnT-trnL and ITS2 trees. The observed sequence divergence supports the existence of a distinct Hymenophyton taxon in southern South America, delimitated from H. flabellatum and H. leptopodum on species level: H. pedicellatum Steph. This reinstated species is described in detail; differentiating morphological and molecular characters are presented. Hymenophyton taxa have a basically palaeoaustral distribution pattern. Biogeography, dispersal biology and phylogeography of the taxa are discussed.
 
Article
According to several authors, the Burmanniales are an order that includes the families Burmanniaceae, Thismiaceae and Corsiaceae. At present, there is no consensus concerning the circumscription of Burmanniales. All members of Thismiaceae and Corsiaceae are mycoheterotrophic; Burmanniaceae are composed of both mycoheterotrophic and autotrophic species. Other than mycoheterotrophy, there are few characters that unite members of the order. Because mycoheterotrophy has resulted in extreme vegetative reduction that may have contributed to homoplasy in the form of character convergence, the systematics of Burmanniales is problematic. A phylogeny inferred from large-subunit (26S) ribosome-DNA sequences suggests that the order Burmanniales is polyphyletic. Specifically, the Burmanniaceae appears as strongly supported monophyletic group with Thismia as sister. Corsia is distinct and may be associated with the Liliales.
 
Article
We reviewed 15572 Australian species-level records of the marine planktonic dinoflagellate Tripos Bory (formerly Ceratium Schrank, a genus now restricted to freshwater species). The genus is represented by over 50 species and numerous varieties and forms in Australian tropical, subtropical and temperate marine waters and the Southern Ocean. There exists considerable plasticity in the morphology of many species, which has confounded species delimitations and created uncertainty around their spatial distributions. We newly illustrate by light and electron microscopy the rarely reported Tripos hundhausenii (Schröd.) Hallegr. & Huisman comb. nov. first described from the Arabian Sea, but increasingly being observed in Sydney coastal waters. A large number of Tripos species are widely distributed in temperate, subtropical and tropical waters and their distributions have remained remarkably stable in Australian waters over the past 60–80 years. By contrast, we identified a narrow group of warm-water species, including T. belone (Cleve) F.Gómez, T. cephalotus (Lemmerm.) F.Gómez, T. dens (Ostenf. & E.J.Schmidt) F.Gómez, T. digitatus (F.Schütt) F.Gómez, T. gravidus (Gourret) F.Gómez, T. incisus (G.Karst.) F.Gómez, T. paradoxides (Cleve) F.Gómez and T. praelongus (Lemmerm.) F.Gómez, that are commonly encountered off Sydney, rarely found down to Eden and Batemans Bay or Bass Strait, but occasionally occur as far south as King Island and Maria Island, Tasmania. These rare tropical Tripos species are carried southward by the East Australian and Leeuwin Currents and deserve careful attention in monitoring for future range expansions, changes in seasonality or upwelling or incursion of deep tropical waters.
 
Article
Menegazzia caliginosa P.James & D.J.Galloway, M. kantvilasii P.James and M. subbullata P.James & Kantvilas are reported for the first time from outside Australasia, and M. dispora (Nyl.) R.Sant. is noted here as a first record for Argentina. We also report the discovery of fertile specimens of M. kantvilasii, with the morphological and anatomical features of its apothecia described. A comparison of the characters of the species of Menegazzia in Argentina is presented. The lichenicolous fungus, Abrothallus parmeliarum (Sommerf.) Nyl., is reported for the first time on specimens of Menegazzia and is also new to the lichen mycobiota of Argentina.
 
Article
A taxonomic revision of Acacia aulacocarpa Cunn. exBenth. and its seven close relatives is presented. These species comprise theA. aulacocarpa group in the AcaciaMill. section Juliflorae and occur naturally in eastern and northernAustralia, New Guinea and Wetar, eastern Indonesia. In the past, the nameA. aulacocarpa has been widely misapplied. This speciesis relatively uncommon but has an extensive geographic range extending fromthe Atherton Tableland region in Queensland, south to northern New SouthWales. Acacia aulacocarpa var.fruticosa C.T.White is considered conspecific withA. aulacocarpa. The nameA. lamprocarpa O.Schwarz is reinstated for a northernAustralian taxon that extends from western Queensland through NorthernTerritory to the Kimberley region of Western Australia. Five new taxa aredescribed from A. aulacocarpa sens. lat., namelyA. celsa Tindale (Queensland),A. disparrima subsp. disparrimaM.W.McDonald & Maslin (northern New South Wales and Queensland),A. disparrima subsp. calidestrisM.W.McDonald & Maslin (Queensland), A. midgleyiM.W.McDonald & Maslin (Queensland) andA. peregrina M.W.McDonald & Maslin (New Guinea).A full description is provided for A. crassicarpa Cunn.ex Benth. Mainly on the basis of their mode of pod dehiscence, two subgroupswithin the A. aulacocarpa group are defined:A. aulacocarpa, A. celsa andA. disparrima comprise theA. aulacocarpa subgroup and have pods that dehisce alongthe dorsal suture; and A. crassicarpa,A. lamprocarpa, A. midgleyi,A. peregrina and A. wetarensiscomprise the A. crassicarpa subgroup and have pods thatdehisce along the ventral suture. All species in the group, including theIndonesian species A. wetarensis, are illustrated and akey to the taxa is provided. Acacia celsa,A. crassicarpa, A. peregrina andA. midgleyi have considerable potential for wood production in tropical plantation forestry.
 
Article
The genus Acacia is subdivided into the following three subgenera: subg. Acacia, subg. Aculeiferum and the predominantly Australian subg. Phyllodineae. Morphological and molecular studies have suggested that the tribe Acacieae and genus Acacia are artificial and have a close affinity to the tribe Ingeae. Sequence analysis of the chloroplast trnK intron, including the matK coding region and flanking non-coding regions, were undertaken to examine taxon relationships within Acacia subgenera Acacia and Aculeiferum. Subgenus Acacia is monophyletic while subgenus Aculeiferum is paraphyletic. Within the subgenera, major divisions are found based on biogeography, New World versus African–Asian taxa. These data suggest that characters such as inflorescence and prickle and/or stipule type are polymorphic and homoplasious in cladistic analyses within the subgenera.
 
Article
The species of Acacia s.l. are currently undergoing a taxonomic upheaval. This is due, in large part, to recent molecular work that has confirmed previous morphological studies and concluded that the genus is not monophyletic. At least five monophyletic lineages have been defined within the genus and, largely on the basis of molecular data, these are distributed throughout the tribes Acacieae, Ingeae and Mimoseae of the Mimosoideae. We provide new and review previous molecular data used to redefine the generic classification of the genus into five segregate genera. The present study doubles the number of plastid base pairs compared with previous studies, to over 7 kb of aligned sequence. These data confirm previous clades and the present is the first to identify robust support for relationships among clades on the backbone of the phylogeny. The support for Vachellia is stronger than for any subclade within it. However, the support for Senegalia s.s. is weaker than it is for each of two subclades within it. There is no support for the former tribal classification with the enlarged dataset. The nomenclatural implications of which clades are recognised at a generic level are discussed.
 
Article
Next-generation sequencing (NGS) provides numerous tools for population and systematic studies. These tools are a boon to researchers working with non-model and poorly characterised organisms where little or no genomic resources exist. Several techniques have been developed to subsample the genomes of multiple individuals from related populations and species, so as to discover variable regions. We describe here the use of a modified AFLPseq method that provides a rapid and cost-effective approach to screening variable gene regions (SNPs) for multiple samples. Our method provides an adaptable toolkit for multiple downstream applications, which can be scaled up or down depending on the needs of the research question and budget. Using minor modifications to the protocol, we successfully recovered variable and useful markers that were applied to three case studies examining different scales of biological organisation, namely, from within populations to phylogenetic questions at the genus level and above. The case studies on Acacia and Eucalyptus generated genomic data across multiple taxonomic hierarchies, including demonstrating the detection of Acacia pinguifolia J.M.Black individuals used in restoration and their population origins, regional phylogeography of Acacia pycnantha Benth., and SNP-marker conservatism across some 70million years of divergence among the Myrtaceae.
 
Article
A new, rare wattle, Acacia daviesii sp. nov., known from only 10 populations discovered in mountainous, subalpine habitat in north-eastern Victoria, is described and illustrated. A comparative morphological study was undertaken, based on phyllode characters measured from all 10 known populations and herbarium specimens of the five most similar Acacia species: A. acinacea, A. aspera, A. glandulicarpa, A. gunnii and A. paradoxa. The new species has a pendulous habit and resinous phyllodes covered by stalked multicellular glands. Acacia daviesii forms clones by root suckering and seed set appears to be rare. Isozyme analysis based on nine enzyme systems showed that plants within any single population are genetically identical. Variation was detected between all but two populations with only nine known genotypes in an area of 12 km2.
 
Article
The first Australia-wide monograph of Amphiroa (Corallinaceae, Rhodophyta) based on the morphological-anatomical species concept has confirmed the occurrence of nine species (A. anceps, A. beauvoisii, A. crassa, A. exilis, A. foliacea, A. fragilissima, A. gracilis, A. klochkovana, A. tribulus) and provides a basis for future molecular-systematics studies. A comparative analysis of 285 specimens from 121 localities, along with type material examinations, yielded clear evidence that nine characters associated with the vegetative system and tetrasporangial conceptacles were diagnostically significant at species level. Detailed accounts of each species are presented, along with an identification key, data on type specimens, species comparisons and biogeographic notes. A. foliacea is epitypified. Brief accounts of 34 additional taxa reported from Australia and at some stage ascribed to Amphiroa are included. Galaxaura versicolor and Amphiroa galaxauroides are heterotypic synonyms of A. anceps; recognition of A. anastomosans, A. ephedraea and A. nobilis as distinct species requires further evaluation; and A. dilatata and A. gaillonii are species of uncertain status. Amphiroa ephedraea is lectotypified. The remaining 27 names involve nomina nuda, illegitimate names, orthographic variants or taxa now excluded from Amphiroa.
 
(continued )
Summary information for the nuclear rDNA used in the study by region Includes aligned length of each partition, the number of variable and parsimony-informative characters (PIC), and the model of evolution used for Bayesian analysis obtained from jModelTest. ETS, external transcribed spacer; ITS, internal transcribed spacer
Examples of co-occurring Gossia species (either immediately adjacent or within 500 m) Voucher details from published references or BRI AQ numbers
Article
The rainforest genus Gossia N.Snow & Guymer (Myrtaceae) occurs in Australia, Melanesia and Malesia, and is capable of hyperaccumulating the heavy metal manganese (Mn). Here, we used nuclear ribosomal and plastid spacer DNA-sequence data to reconstruct the phylogeny of 19 Australian species of Gossia and eight New Caledonian taxa. Our results indicated that the relationship between Gossia and Austromyrtus (Nied.) Burret is not fully resolved, and most Australian species were supported as monophyletic. Non-monophyly might be related to incomplete lineage sorting or inaccurate taxonomic classification. Bark type appears to be a morphological synapomorphy separating two groups of species, with more recently derived lineages having smooth and mottled ‘python’ bark. New Caledonian species were well resolved in a single clade, but were not the first diverging Gossia lineage, calling into doubt the results of a recent study that found Zealandia as the ancestral area of tribe Myrteae. Within Australia, the evolution of multiple clades has probably been driven by well-known biogeographic barriers. Some species with more widespread distributions have been able to cross these barriers by having a wide range of soil-substrate tolerances. Novel Mn-hyperaccumulating species were identified, and, although Mn hyperaccumulation was not strongly correlated with phylogenetic position, there appeared to be some difference in accumulation levels among clades. Our study is the first detailed phylogenetic investigation of Gossia and will serve as a reference for future studies seeking to understand the origin and extent of hyperaccumulation within the Myrteae and Myrtaceae more broadly.
 
Article
The present paper completes a revision of the endemic Australian genus Cassinia R.Br. Cassinia subgenus Achromolaena comprises two sections, namely, section Achromolaena of seven species (C. laevis, C. arcuata, C. uncata, C. tenuifolia, C. collina, C. subtropica, and C. quinquefaria), and Cassinia section Siftonia, which contains two species (C. sifton and C. theodorii). Cassinia laevis is divided into western (C. laevis subsp. laevis) and eastern (C. laevis subsp. rosmarinifolia (A.Cunn.) Orchard, comb. et stat. nov.) taxa. Examination of the type of C. arcuata showed that this name is synonymous with C. paniculata, and applies to a relatively rare taxon with whitish capitula arranged in short erect compact panicles, and found in Western Australia, the midlands of South Australia, western Victoria and (formerly) south-western New South Wales. Furthermore, it belongs to section Achromolaena. The taxon with red to brown capitula, widespread throughout south-eastern Australia, which until now has been (incorrectly) known as C. arcuata (Sifton bush) is distinct, but lacks a published name. The name Cassinia sifton Orchard, sp. nov. is here proposed for this taxon. An unfortunate outcome of this discovery is that the sectional name Cassinia section Arcuatae, with C. arcuata as type, becomes synonymous with section Achromolaena. The new name Cassinia section Siftonia is proposed to accommodate Sifton bush (C. sifton) and its narrowly endemic sister species C. theodorii. A summary of the whole genus is provided, with keys to all taxa. Three former subspecies of C. macrocephala are raised to species rank (C. petrapendula (Orchard) Orchard, C. storyi (Orchard) Orchard, C. tenuis (Orchard) Orchard), and it is suggested that C. furtiva Orchard may be conspecific with C. straminea (Benth.) Orchard.
 
Article
The taxonomic position of Backhousia anisata is reassessed on morphological and anatomical grounds and its affinities found to lie with the Acmena alliance. Backhousia anisata is glabrous and has a suite of wood anatomical character-states that are more consistent with a phylogenetic position in or near the Acmena alliance than with other Backhousia species; molecular data also support this placement. Since this species lacks the fleshy fruit, thick cotyledons and hypogeal germination characteristic of other members of the Acmena alliance, a new genus Anetholea Peter G.Wilson is described to accommodate it, and the new combination Anetholea anisata (Vickery) Peter G.Wilson made.
 
Article
Molecular evidence supports the transfer of Conoscyphus Mitt. from Lophocoleaceae to Acrobolbaceae, which is unexpected on the basis of morphological evidence and further disrupts the morphological circumscription of Acrobolbaceae. Conoscyphus differs from other Acrobolbaceae in possessing a stem perigynium and a conspicuous perianth that forms a tube, large underleaves that produce rhizoids in a fascicle from the underleaf disc, and shoots that grow inverted when hanging free from the substrate. However, Conoscyphus shares with other Acrobolbaceae granular brown oil bodies, a multistratose capsule, absence of terminal branching and papillose leaf cell-surface ornamentation. To reflect the morphological differences, particularly in post-fertilisation reproductive structures, between Conoscyphus and other members of the family, we retain subfamily Conoscyphoideae and transfer it to Acrobolbaceae.
 
Article
Ceratopetalum macrophyllum sp. nov. from north-eastern Queensland is described. For reasons of priority the name Acrophyllum has to be accepted for the genus previously treated under the name Calycomis; Acrophyllum australe comb. nov. is the correct name for the only species.
 
Article
Mycoheterotrophs, i.e. plants that acquire carbon from root-associated soil fungi, often have highly degraded plastomes, reflecting relaxed selective constraints on plastid genes following the loss of photosynthesis. Geosiris Baill. is the only mycoheterotrophic genus in Iridaceae and comprises two species in Madagascar and nearby islands, and a third recently discovered species in north-eastern Australia. Here, we characterise the plastomes of the Australian and one Madagascan species to compare patterns of plastome degradation in relation to autotrophic and other mycoheterotrophic taxa and investigate the evolutionary and biogeographical history of the genus in Iridaceae. Both examined species have lost approximately half their plastid-encoded genes and a small but significant reduction in purifying selection in retained non-photosynthetic genes was observed. Geosiris is confirmed as monophyletic, with initial divergence of the genus occurring c. 53 million years ago, and subsequent diversification occurring c. 30 million years ago. Africa (including Madagascar) is reconstructed as the most likely ancestral area of the genus, implying a major range-expansion event of one lineage to Australia after its divergence in the Oligocene. Our study has highlighted the dynamic evolutionary history of Geosiris, contributed to the characterisation of mycoheterotrophic plastomes, and furthered our understanding of plastome structure and function.
 
Article
Leaf architecture was investigated in three species of the family Bombacaceae. The mature leaflets from both fresh and herbarium materials were cleared using the method of Mohan Ram and Nayyar (1977), and terminologies of Hickey (1973) were used to determine the leaf characters and the venation patterns. The whole lamina is more or less symmetrical in all the species investigated. The major venation pattern conforms to the types of camptodromous mixed with festooned brochidodromous, and festooned brochidodromous. In all the members of the family studied, the primary and secondary veins are ornamented with parenchymatous bundle sheaths. Imperfectly developed areoles are predominant over the developed ones. The size and the shape of the areole is variable. The vein endings may be simple, or once or sometimes twice dichotomously branched. The highest venation order of the family is sixth degree. Marginal ultimate venation is looped. Tracheids are either uni-, bi-, tri-, or multi-seriate and vary in shape and size, and are commonly found at the free ends of the veins. Extension cells and isolated tracheids are not common. These characters are remarkably different from those in members of the Malvaceae.
 
Top-cited authors
Robert S Hill
  • University of Adelaide
William J. Woelkerling
  • La Trobe University
As Harvey
  • La Trobe University
Gregory J Jordan
  • University of Tasmania
Joe Miller
  • Global Biodiversity Information Facility