Australian Systematic Botany 

About: Australian Systematic Botany is an academic journal published by CSIRO Publishing. The journal publishes majorly in the area(s): Systematics & Monophyly. It has an ISSN identifier of 1030-1887. Over the lifetime, 1062 publications have been published receiving 19580 citations. The journal is also known as: Australian systematic botany : an international journal devoted to the taxonomy, biogeography and evolution of all plant groups..

L. A. S. JOHNSON REVIEW No. 2 Use of nuclear genes for phylogeny reconstruction in plants

Abstract: Molecular data have had a profound impact on the field of plant systematics, and the application of DNA-sequence data to phylogenetic problems is now routine. The majority of data used in plant molecular phylogenetic studies derives from chloroplast DNA and nuclear rDNA, while the use of low-copy nuclear genes has not been widely adopted. This is due, at least in part, to the greater difficulty of isolating and characterising low-copy nuclear genes relative to chloroplast and rDNA sequences that are readily amplified with universal primers. The higher level of sequence variation characteristic of low-copy nuclear genes, however, often compensates for the experimental effort required to obtain them. In this review, we briefly discuss the strengths and limitations of chloroplast and rDNA sequences, and then focus our attention on the use of low-copy nuclear sequences. Advantages of low-copy nuclear sequences include a higher rate of evolution than for organellar sequences, the potential to accumulate datasets from multiple unlinked loci, and bi-parental inheritance. Challenges intrinsic to the use of low-copy nuclear sequences include distinguishing orthologous loci from divergent paralogous loci in the same gene family, being mindful of the complications arising from concerted evolution or recombination among paralogous sequences, and the presence of intraspecific, intrapopulational and intraindividual polymorphism. Finally, we provide a detailed protocol for the isolation, characterisation and use of low-copy nuclear sequences for phylogenetic studies.

A new classification of the genus Eucalyptus L'Hér. (Myrtaceae)

Abstract: A new formal classification of the genus Eucalyptus is presented. It divides the genus into seven polytypic subgenera: E. subg. Angophora, E. subg. Corymbia, E. subg. Blakella, E. subg. Eudesmia, E . subg. Symphyomyrtus, E. subg. Minutifructa and E. subg. Eucalyptus, and six monotypic subgenera: E. subg. Acerosa, E. subg. Cruciformes, E. subg. Alveolata, E. subg. Cuboidea, E. subg. Idiogenes and E. subg. Primitiva. The system is intentionally phylogenetic, proceeding from the generally assumed primitive ‘apples’ (E. subg. Angophora) and bloodwoods (E. subg. Corymbia) to the most advanced and modified group, the monocalypts (E. subg. Eucalyptus). The genus Corymbia Hill & Johnson is subsumed under Eucalyptus and is represented by E. subg. Corymbia (the bloodwoods) and E. subg. Blakella (the ghostgums). New infrageneric taxa are diagnosed and their names typified, while brief digests in English are given for established taxa. Three species of the former genus Angophora have names with epithets preoccupied by names of other Eucalyptus species and new names are presented for them. The study is introduced by a brief historical summary of previous work in Eucalyptus, an apologia for the inclusion of Angophora, the reason for requirement of a new classification and notes on the nomenclature used. A new infrageneric rank, ‘supraspecies’, is introduced and is intentionally divorced in application (as a rank) from the similar sounding ‘superspecies’. All species recognised by the author are named and assigned in this system.

Growth-forms in non-geniculate coralline red algae (Corallinales, Rhodophyta)

Abstract: Although differences in growth-form have been widely used in delimiting taxa of non-geniculate coralline red algae (Corallinales, Rhodophyta), there has been no consistent application of the more than 100 terms employed to describe the growth-forms present, and considerable confusion has resulted. This study of over 5000 populations of non-geniculate corallines from all parts of the world has shown that an intergrading network of growth-forms with 10 focal points is present: unconsolidated, encrusting, warty, lumpy, fruticose, discoid, layered, foliose, ribbon-like and arborescent. This focal point terminology can be used to describe any specimen or species of non-geniculate coralline in a consistent, easily interpretable manner. Details of the system are provided, the relationships of the system to past proposals are discussed, and the extent to which differences in growth-forms can be used as taxonomic characters in the non-geniculate Corallinales is reviewed.

Patterns of diversification within continental biotas: Hierarchical congruence among the areas of endemism of Australian vertebrates

Abstract: This paper investigates the extent to which there is hierarchical information about area-relationships contained in the distributions of Australian vertebrates. Distributions of genera, their included species, and their included subspecies (when appropriate) were coded present/absent for 14 areas of endemism. The data were then analysed cladistically and most parsimonious area-cladograms constructed; bootstrap consensus trees were used to assess the strength of the cladistic signal. Distributions of birds and mammals were found to be nearly identical in their hierarchical pattern, and snakes shared the same general pattern of area-relationships. Frogs and lizards exhibited greater differences but were still congruent in some respects. This congruence calls for a general explanation. It is proposed that either the pattern can be explained in terms of (1) true area-relationships (vicariance), in which case biogeographic noise, including redundant distributions and widespread taxa do not disturb historical signal; (2) constraints on processes or events that lead to congruent histories of cosmopolitanism; or (3) a combination of both.

Overview of the generic status of Acacia (Leguminosae: Mimosoideae)

Abstract: The systematic treatment and circumscription of the group of plants presently recognised as the genus Acacia has a complex history. The genus was first described by Philip Miller in 1754 and until 1842, when George Bentham clearly defined it's generic limits (by restricting the name Acacia to mimosoid plants having numerous free stamens), a number of species which are now referable to genera within tribes Ingeae and Mimoseae had been referred to it. As presently defined, Acacia is a cosmopolitan genus containing in excess of 1350 species and together with the monotypic genus Faidherbia Chev. (which occurs in Africa and the Middle East), comprises tribe Acacieae within subfamily Mimosoideae. The current classification of Acacia views the genus as comprising three large subgenera, namely subg. Acacia (c. 161 species, pantropical), subg. Aculeiferum Vassal (235 species; pantropical) and subg. Phyllodineae (DC.) Seringe (syn. subg. Heterophyllum Vassal) (960 species, largely confined to Australia). In 1986, Pedley proposed that these three subgenera be attributed generic rank, namely Acacia, Senegalia Rafinesque and Racosperma C.Martius, respectively, but this proposal was not widely adopted. Subsequently, the results of monographic and floristic works have greatly expanded knowledge, not only of Acacia, but also of its presumed relatives in tribes Ingeae and Mimoseae. Cladistic analyses of chloroplast genes have been especially informative in developing a better understanding of phylogenetic relationships of the group. The new data clearly show that the genus as presently defined (i.e. Acacia sens. lat.) is not monophyletic. Furthermore, five separate monophyletic groups can be recognised within Acacia sens. lat. and it is recommended that these each be recognised as a distinct genus. The five genera correspond to those recognised by Pedley, except that Senegalia sens. lat. is now regarded as comprising three genera, namely Senegalia sens. str., Acaciella Britton & Rose [based on Acacia subg. Aculeiferum sect. Filicinae (Benth.) Pedley] and an undescribed genus based on a group of species related to Acacia coulteri Benth. Acacia subg. Acacia appears to be located in tribe Mimoseae. The relationships of subg. Phyllodineae, subg. Aculeiferum sens. str., sect. Filicinae, the 'Acacia coulteri' group and Faidherbia are not fully resolved, although in all studies these groups are shown to be monophyletic. Although it is appropriate that each be recognised as a distinct genus, the application of the names Acacia and Racosperma is currently under consideration and it is therefore not appropriate to use these names until this matter is resolved.