Philotheca

Abstract: This thesis considers the relationships, classification and historical biogeography of the related Australian endemic flowering plant genera Philotlzeca, Eriostemon and Crowea (family Rutaceae, tribe Boronieae). It focuses mostly on relationships within and between these genera, but also considers the relationships of these groups to other members of the tribe Boronieae, particularly the small genera Geleznowia and Drummondita. It includes a brief appraisal of the species-level taxonomy of Philotheca, Eriostemon and Crowea, a survey of morphological characters, a survey of leaf phenolic compounds, and a series of cladistic and biogeographic analyses. The appraisal of species-level taxonomy identified terminal taxa suitable for use in cladistic analyses, and has resulted in the recognition of one new species (Philotheca sporadica) and three new subspecies (P. myoporoides subsp. brevipedunculata, subsp. euroensis, and subsp. obovat(j(Jlia), as well as a recommendation to reinstate one species (Eriostenwn banksii, which was previously reduced to subspecific status under/'.,'. austrolasius). The survey of morphological variation identified I 08 morphological characters, 99 of which are potentially useful in the assessment of relationships, and nine that are unique to single terminal taxa. The survey of leaf phenolics was based on two-dimensional paper chromatography, and the chromatographic properties and distributions of 26 compounds arc reported. Twenty-three of these compounds arc potentially useful in the assessment of relationships, and three are unique to single terminal taxa. Assessment of the higher-level relationships of Philotheca, Eriostemon and Crowea (to each other and to other taxa of Boronieae) was based on reappraisal, and re-analysis, of a previous phylogenetic analysis (Armstrong 1991 ). This reappraisal was based on a limited set of morphological characters, and used genera, sections within genera, and some species as terminal taxa. ln general higher-level relationships of the three genera were either poorly resolved or poorly supported. A close relationship of

Abstract: The leaf oils of the species of Philotheca growing in Queensland and northern New South Wales have been examined by combined GC and GC/MS. Philotheca cuticularis, both subspecies of P. difformis, P. glasshousiensis, P. myoporoides subsp. myoporoides, P. epilosa, P. obovata, P. queenslandica and P. sporadica all produced leaf oils in which the major component (<75%) was α-pinene. In P. acrolopha, the major components were α-pinene (34–42%) and β-caryophyllene (12–22%), while in P. ciliata the principal components were α-pinene (48–54%) and camphor (18–25%). In P. ericifolia the major components were α-pinene (16–25%), myrcene (7–10%), (E)-β-ocimene (18–34%) and the sesquiterpene spathulenol (13–21%). Pilotheca conduplicata produced a monoterpenic oil in which the main components were α-pinene (27.2%), limonene (43.8%) and (E)-β-ocimene (18.3%). In Philotheca papillata α-pinene (43.0%), camphene (9.3%) and elemol (8.8%) were the principal components of the leaf oil. The leaf oil of P. salsolifolia ...