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Some phytogeographical, zoogeographical and biogeographical regionalisations of the world are reviewed qualitatively. A biogeographical regionalisation attempting some consensus is proposed, recognising the following three kingdoms and nine regions: Holarctic kingdom (Nearctic and Palearctic regions), Holotropical kingdom (Neotropical, Ethiopian and Oriental regions) and Austral kingdom (Cape, Andean, Australian and Antarctic regions). Additionally, the following five transition zones are recognised: Mexican (Nearctic–Neotropical transition), Saharo-Arabian (Palearctic–Ethiopian transition), Chinese (Palearctic–Oriental transition), Indo-Malayan (Oriental–Australian transition) and South American (Neotropical–Andean transition).
The genus Pycnandra Benth. (Sapotaceae, Chrysophylloideae) is endemic to New Caledonia with 66 known species and is subdivided in six subgenera. We have earlier revised four of these subgenera and here continue with P. subgenus Leptostylis and describe P. subgenus Wagapensia. Subgenus Leptostylis is distinguished mainly by its opposite leaves and four sepals, and includes eight species, of which two are described as new (P. amplexicaulis and P. sclerophylla). Two species, P. longiflora and P. micrantha, are assumed extinct because extensive fieldwork has not been able to relocate the plants. Variation in leaf morphology was observed in Leptostylis gatopensis, which is by consequence considered as synonym of Pycnandra filipes. Two additional taxa belong to this subgenus, but cannot presently be described because sufficient fertile material is unavailable. Subgenus Wagapensia is monotypic and readily distinguished on the basis of its subverticillate leaves and leafy shoots usually borne beneath apical clusters of leaves, a character common in Sapotaceae but unique in Pycnandra. The members of P. subgenus Leptostylis occur mainly in maquis vegetation or sclerophyllous forests on ultramafic soil, but three taxa are confined to calcareous areas. Mining activities in New Caledonian ultramafic areas are extensive and because some of these species are naturally rare, IUCN Red List assessments are provided to all species. Pycnandra grandifolia and P. wagapensis are assigned the IUCN status Vulnerable, P. amplexicaulis and P. sclerophylla are considered Endangered, P. filipes subspecies multiflora and P. goroensis are considered to be Critically Endangered, whereas P. micrantha and P. longiflora appear to be extinct.
As currently circumscribed, Boronia (Rutaceae) is a large Australian genus of 148 species distributed in all states and mainland territories, and Boronella is confined to New Caledonia and contains ∼four species. We present molecular phylogenetic analyses of these genera, based on chloroplast (trnL–trnF) and nuclear (ITS, ETS) DNA sequences, to assess their relationships and infrageneric classification. Analyses strongly support the monophyly of a BoroniaBoronella clade and that Boronella is nested within Boronia. They also support the monophyly of Boronella and Boronia sections Algidae, Valvatae and Cyanothamnus, and ser. Pedunculatae (sect. Boronia), but resolve sect. Boronia and ser. Boronia as polyphyletic. On the basis of these results, we propose a new classification wherein Boronella is transferred to Boronia and recognised at the rank of section, and a new name and two new combinations in Boronia are provided for the following three species: Boronia hartleyi Duretto & Bayly, Boronia pancheri (Baill.) Duretto & Bayly and Boronia parvifolia (Baker f.) Duretto & Bayly. A revised circumscription is presented for Boronia sect. Boronia, and Pedunculatae is elevated from a series to a section. The relationships and classification of some taxa require further clarification, either because of limited taxon sampling, or because some nodes in phylogenetic analyses are poorly resolved or supported.
Holoparasitic genera within family Orobanchaceae are characterised by greatly reduced vegetative organs; therefore, seed micromorphology has proved to be a useful complementary taxonomic criterion. Seeds of 160 samples from 54 localities of 26 taxa of the Orobanche and Phelipanche genera occurring in central Europe, specifically from Poland, the Czech Republic, Austria and Slovakia, supplemented by samples from Spain, France and Ukraine, were investigated using scanning electron microscopy. Thirteen quantitative or qualitative morphological characters of seeds were analysed. The following three types of periclinal wall sculpture of seeds were identified: veined and fibrillar in Phelipanche; with oval or elliptic perforations (pitted) in almost all species of Orobanche; with outer periclinal wall smooth, granular or rugged (very rarely visibly pitted), impeding vision of the inner one, occurring only in O. gracilis Sm. and O. coerulescens Stephan in Willd. The influence of different hosts on the features of seeds of eight species is also presented, as well as relationships between seed morphology and taxonomic classification, including problematic taxa. The best diagnostic features include type of ornamentation of the periclinal wall, perforation diameter (in pitted sculpture), fibrillar diameter (in fibrillar sculpture) and width of anticlinal walls. Size and shape of the seeds and cells and the presence of median troughs are variable; however, these features can be helpful when using larger samples. The usefulness of micromorphological studies on seeds of Orobanche and Phelipanche is demonstrated.
The phylogenetic placement of Monocarpus sphaerocarpus D.J.Carr (Monocarpaceae), a member of the complex thalloid liverworts with highly specialised morphology, presumably related to its saltpan habitat, has been determined on the basis of molecular data. Within the complex thalloid liverworts, Monocarpus resolves as sister to the Sphaerocarpales clade. A new line drawing of Monocarpus is provided, as are the first colour photographs of living plants. Detailed ornamentation of the spores of Monocarpus collections from Australia and South Africa, as revealed by scanning electron micrography, is reported, and some of the morphological features that unite and separate Monocarpus and the Sphaerocarpales s.str. are discussed.
Mitotic metaphase chromosomes were counted in 29 taxa, representing 11 subgenera of Austrostipa, and in 11 species from nine related genera of the grass subfamily Pooideae. Karyotype features were also measured. The cytogenetic data were mapped on molecular phylogenetic trees based on nuclear ITS and plastid 3′ trnK DNA sequence data. The trees showed four different main lineages within Austrostipa, but supported only two of the 13 acknowledged subgenera. The phylogenetic positions of the genera Anemanthele, Achnatherum, Nassella and Oloptum indicated paraphyly of the genus Austrostipa. In nuclear-sequence data, Anemanthele was nested within Austrostipa; however, in plastid-sequence data, both were sisters. The newly obtained chromosome counts in Austrostipa showed that most species have 2n = 44, the other 2n = 66. Presuming a chromosome base number of x = 11, the counts corresponded with ploidy levels of 4x and 6x respectively. Karyotype data of Austrostipa and Anemanthele were very similar. Chromosome counting in further genera suggested chromosome base numbers of x = 9, 10, 11, 12 and 13. Chromosome sizes of the phylogenetically derived tribe Stipeae were smaller than those of the earliest diverging Pooideae lineages Nardeae, Meliceae and Phaenospermateae. The mechanisms of chromosome evolution and the origin of the considerable variation in chromosome base numbers in the subfamily Pooideae are discussed in the context of chromosome evolution and biosystematics.
Comparative wood anatomy of Taxaceae s.l. was examined to elucidate the differences in wood features among genera. In total, 25 samples, comprising three varieties and seven species from five genera (Pseudotaxus was not included), were examined. Sliding microtome, wood maceration and scanning electron microscopy methods were used for the study. The growth rings are well developed and early and late wood are distinguishable in a cross-section. In general, there is remarkable uniformity in the characteristics of the five genera of Taxaceae, although some differences in quantitative traits were found. Wood of Taxaceae s.l. differs from that of most conifers by having helical thickening in the tracheid inner walls, with the exception of Austrotaxus spicata R.H.Compton. All genera are characterised by the absence of resin canals, predominantly uniseriate pits on the radial wall of the axial tracheids, and the presence of pits on the tangential walls of the axial tracheids. The rays are composed solely of parenchyma cells and are uniseriate (occasionally biseriate in Torreya nucifera (L.) Siebold et Zucc.), with a height of 1–22 cells. The genus Taxus shares more characteristics with Torreya than with Amentotaxus, Austrotaxus and Cephalotaxus. Correspondingly, Amentotaxus and Cephalotaxus resemble each other, marked by the presence of either diffuse or sparse axial parenchyma with nodulated transverse walls. Austrotaxus spicata is the sole species that lacks helical thickenings in the tracheid walls and has sparse axial parenchyma with smooth transverse walls. These two features, namely, the absence of helical thickenings and axial parenchyma with smooth transverse walls, are plesiomorphic and might be considered a more primitive character in wood anatomy. Among the other four genera, Amentotaxus appears to have an annular type of wall thickening that could be considered plesiomorphic to the spiral thickenings found in Taxus, Torreya and Cephalotaxus.
The taxonomic significance of cypsela features of South American species of Lessingianthus (Vernonieae, Asteraceae) is analysed for the first time and discussed in relation to other genera of the tribe Vernonieae. The morphology of the cypselae of 112 species of the genus were analysed using stereo-, light and scanning electron microscopy (SEM) to evaluate the infrageneric relationships and their reliability as taxonomic markers at a generic level. Characters such as cypsela pubescence, carpopodium structure, crystals and idioblasts on the fruit wall were examined. We established three types of cypsela on the basis of the presence or absence, and type of trichomes. Carpopodium is present in all species of the genus. Crystals are very variable in shape and size, with prismatic (rectangular and hexagonal) and styloid shapes. Idioblasts are present in all of the species, except for two. Cypsela features of Lessingianthus are often widespread in other related genera of Vernonieae. Therefore, these characters are not good taxonomic markers at the genus level, but they are valuable within genera to differentiate related species from one another.
We present the case that the fossil record of Nothofagaceae, which is much more extensive in terms of species numbers than the living species, cannot be dealt with in a productive way by the recent proposal by Heenan and Smissen to split Nothofagus into four genera (Phytotaxa, vol. 146, http://dx.doi.org/10.11646/phytotaxa.146.1.1). Such a proposal will render the fossil record almost unworkable, and will lead to a major split in the approach taken by palynologists in comparison to other researchers. We believe the case for the new generic names, while valid, is weak, and is far outweighed by the utility of retaining Nothofagus sensu lato.
The transfer of all species of Dryandra into Banksia in 2007, resulting from phylogenetic studies demonstrating that the latter is paraphyletic with respect to the former, generated controversy in some sections of the community. In a recent paper, Alex George, a taxonomist of long standing and monographer of both genera, criticised the transfer, and its subsequent acceptance by the Australian herbarium and plant systematics community. More broadly, George criticised the direction of modern taxonomy, particularly its basis in phylogenetic analysis and monophyly. His criticisms reflect adherence to a largely pre-Darwinian taxonomic tradition, methodology, practice and conceptual framework. This framework, developed in the late 18th and early 19th centuries, and later operationalised as the phenetic method, has for most taxonomists been superseded by the phylogenetic framework for taxonomy developed by and following Willi Hennig. The criticism of the Dryandra transfer by George and colleagues on one hand, and its acceptance by the majority of practicing systematists on the other, is thus an example of competition between differing paradigms rather than George’s claimed specific shortcomings of the transfer or the analyses on which it was based.
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