Paul A. Gadek

Relationships within Cupressaceae sensu lato: a combined morphological and molecular approach.

Parsimony analysis of matK and rbcL sequence data, together with a nonmolecular database, yielded a well-resolved phylogeny of Cupressaceae sensu lato. Monophyly of Cupressaceae sensu stricto is well supported, and separate northern and southern hemisphere subclades are resolved, with Tetraclinis within the northern subclade; there is no support for any of the tribes sensu Li. Taxodiaceae comprise five separate lineages. Chamaecyparis nootkatensis falls within Cupressus, clustering with a robust clade of New World species. Libocedrus Florin is paraphyletic and should incorporate Pilgerodendron. Evolution of several characters of wood and leaf anatomy and chemistry is discussed in light of this estimate of the phylogeny; numerous parallelisms are apparent. A new infrafamilial classification is proposed in which seven subfamilies are recognized: Callitroideae Saxton, Athrotaxidoideae Quinn, Cunninghamioideae (Sieb. & Zucc.) Quinn, Cupressoideae Rich. ex Sweet, Sequoioideae (Luerss.) Quinn, Taiwanioideae (Hayata) Quinn, Taxodioideae Endl. ex K. Koch. The rbcL sequence for Taxodium distichum is corrected, and the implications for a previously published estimate of the minimum rate of divergence of the gene since the Miocene are highlighted.

Biflavones of the subfamily Cupressoideae, Cupressaceae

Abstract Thirty species, representing all eight genera of the subfamily Cupressoideae, were examined for biflavonoid content of the leafy twigs. The major biflavonoid constituents are based on amentoflavone, cupressuflavone and hinokiflavone. The affinities suggested by biflavonyl distribution do not correlate with the currently recognized tribal groupings. There is evidence of closer links between northern and southern hemisphere genera than would be expected on the basis of the presently recognized subfamilies.

Biflavones of Dacrydium sensu lato

Abstract A survey of the biflavonyls in the leaves and branchlets of all three sections of the genus Dacrydium s.l. revealed a complex mixture of amentoflavone and its partial methyl ethers and hinokiflavone in most species. A group of three species in section C, however, were characterised by cupressuflavone derivatives as the major biflavone constituents. The results are used to discuss proposals for revised generic boundaries.

A reassessment of the familial affinity of the Mexican genus Recchia Moçiño & Sessé ex DC

Sequence data for the rbcL locus were obtained for two of the three species of the Mexican endemicRecchia. Parsimony analyses of the molecular data base indicate that Surianaceae sensu Cronquist are paraphyletic; inclusion ofRecchia rendered the family monophyletic. This placement is corroborated by a suite of morphological characters: an apocarpous (or monocarpic), gynoecium of bi-ovulate carpels with basal-marginal placentation and a ventrobasal style, and the occurrence in all butGuilfoylia of a characteristic 3-layered endocarp. The molecular data support a closer relationship betweenRecchia and the AustralianCadellia than between the latter and any of the other Australian genera. The molecular data suggest that the affinities of Surianaceae lie in a clade comprising at least Polygalaceae, Fabaceae, andQuillaja.

Exine Structure in the ‘Cotuleae’ (Anthemideae, Asteraceae)

Abstract Pollen of representatives of all genera previously assigned to the ‘Cotuleae’, as well as Minuria from the Astereae, is described from studies under light microscopy and scanning and transmission electron microscopy. Cotula s. str., Leptinella, Nananthea and Soliva are characterized by exines with anthemoid structure; this supports the conclusion that these are natural members of the tribe Anthemideae. The affinities of the non-anthemoid genera are discussed in the light of data on exine structure. Abrotanella, Ischnea and Centipeda have senecioid exines, while Ceratogyne, Dimorphocoma, Elachanthus, Isoetopsis, Minuria and Plagiocheilus have helianthoid exines. Marked differences are shown between the exines of Abroianella and Ischnea which do not support the existence of a very close affinity between them. Evidence is provided to support the link between Isoetopsis and Elachanthus that has been proposed on the basis of cypsela characters.

Biflavones and the affinities of Cupressus funebris

Abstract The biflavonyl profile of Cupressus funebris consists of major amounts of amentoflavone and cupressuflavone, minor concentrations of hinokiflavone, 7″-monomethylhinokiflavone, and a monomethylrobustaflavone, and traces of monomethylamentoflavone and cupressuflavone derivatives. This is consistent with the pattern reported for other Cupressus species, and does not support the transfer of this species to Chamaecyparis as has been proposed.

Biflavonoids from the seed testa of cycadales

Abstract Biflavonoid patterns from ethanolic extracts of the brightly coloured testa of eight species of Cycadales have been determined. Species from the genus Macrozamia are characterized by the occurrence of cupressuflavone- and amentoflavone-based patterns, while the Cycas species contain only amentoflavone-based patterns. The other species from the genera Encephalartos , Lepidozamia , and Zamia contain a very minor or no detectable biflavonoid component. This is the first report of the occurrence of cupressuflavone in the Cycadales.