Cladistic analysis and revision of Billardiera (Pittosporaceae)

Cladistic analyses of morphological data were used to clarify the definition of Billardiera in the context of other genera of the family Pittosporaceae. These analyses indicate that Billardiera s.str. is monophyletic including the small genera Sollya an

Nanotunnels and pull-aparts: Defects of exsolution lamellae in alkali feldspars

We have studied defects associated with flat, lens-shaped perthitic albite lamellae in alkali feldspars using SEM and TEM. In orthoclase phenocrysts from the Shap granite, Cumbria, NW England, bulk composition Or70.20Ab29.05 An0.85, no dislocations were found even in optically "fresh" parts of grains. Instead, dissolution inferred to be localized on edge-dislocation loops has created tiny "nanotunnels" typically 148 h at 1000 °C and >5748 h at 700 °C. Below the coherent solvus, exsolution lamellae thin on heating, leaving nanotunnels stranded in the orthoclase matrix. Microtextures related to Si-Al ordering patterns in the framework, such as Albite twins, are not eliminated, forming ghost-like lamellar strain patterns in chemically homogeneous feldspar. The presence of nanotunnels in optically "fresh" alkali feldspars shows that not only granites but also granulite-facies rocks have been pervasively affected by fluids at low T. Both nanotunnels and pull-aparts have important implications for feldspar reactivity in the upper crust, for 18O exchange, and for transport of 40Ar both in nature and in laboratory step-heating

Bursaria (Pittosporaceae): a Morphometric Analysis and Revision

Bursaria is an endemic Australian genus of mostly spinescent, scruffy shrubs and trees, found in all but the most arid or alpine areas. Previous classifications include many infraspecific taxa and have proved unworkable in eastern Australia. This paper presents a revision of the genus. On the basis of phenetic analyses of morphometric characters the following taxa are now recognised: B. calcicola L.Cayzer, Crisp and l.Telford, B. incana Lindl., B. longisepala Domin, B. occidentalis E.M.Benn., B. reevesii L.Cayzer, Crisp and l. Telford, B. spinosa Cav. subsp, lasiophylla (E.M.Benn.) L.Cayzer, Crisp and I. Telford, B. spinosa subsp, spinosa and B. tenuifolia F.M.Bail. Two are described as new (B. calcicola, B. reevesii), and one is changed in rank: B. spinosa subsp, lasiophylla (formerly B. lasiophylla E.M.Benn.). None of the other infraspecific taxa recognised previously is supported by our analyses

Revision of Rhytidosporum (Pittosporaceae)

As part of a revision of the family Pittosporaceae in Australia, a cladistic analysis was undertaken to resolve the phylogeny of Rhytidosporum and thereby clarify the taxonomic status of this small genus. Rhytidosporum is confirmed as a separate genus, and five species are now recognised: R. alpinum, R. diosmoides, R. inconspicuum, R. procumbens and R. prostratum. Rhytidosporum inconspicuum, found in subalpine areas mainly in Victoria and Tasmania, is described for the first time. Rhytidosporum diosmoides, which ranges from central New South Wales to southern Queensland, is reinstated at species level