The Ericoideae and the southern African heathers

OLIVER, E. G. H., 1989. The Ericoideae and the southern African heathers. The subfamily Ericoideae (Ericaceae) containing the true heathers and heaths has been a group long recognized as a sound natural entity. With work on the southern African genera and species which comprise approximately 95% of the subfamily well in progress, a reassessment of the number of genera has become necessary because of the considerable variation recorded in, and the postulated polyphyletic origin of, the capsular genera. Changes envisaged will affect the whole concept of the heaths within Africa. The genus Philippia Klotzsch has been reduced to synonymy under Erica L. and it is shown that the case for a similar action is very strong for Blaeria L. and Ericinella Klotzsch. The position of the monotypic European genus, Bruckenthalia Reichb., is also affected but remains unresolved.     

Bactericidal and antioxidant effects of essential oils from Satureja montana L., Myristica fragrans H. and Cymbopogon flexuosus

The extraction and characterization of the essential oils (EO) from Satureja montana L., Myristica fragrans H. and Cymbopogon flexuosus and the determination of their antibacterial and antioxidant activities were achieved. The EO were identified by gas chromatography/mass spectrometry and quantified by gas chromatography using a flame ionization detector. The antibacterial potential against Escherichia coli and Staphylococcus aureus was evaluated by cell susceptibility assays and by scanning electron microscopy. The antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl assay, by β-carotene bleaching and by determining the reducing power. Borneol (36·18%), γ-terpineol (12·66%) and carvacrol (11·07%) were the principal components in the EO from S. montana, and sabinene (49·23%) and α-pinene (13·81%) were found in the EO from M. fragrans. Geranial (59·66%) and neral (38·98%) isomers were the only major components in the EO from C. flexuosus. The EO from S. montana was effective against E. coli, with minimum inhibitory and bactericidal concentrations (MIC and MBC) of 6·25 µl ml⁻¹, whereas bactericidal potential against both was observed for the EO from M. fragrans; MIC = 6·25 µl ml⁻¹ for S. aureus and MBC = 12·5 µl ml⁻¹ for E. coli. A significant protective role on lipid substrates in the β-carotene bleaching assay was seen for the EO from S. montana and M. fragrans. Overall, such EO can be promising agents against pathogenic bacteria and for protecting biomolecules during oxidative stress.     

Étude sur la végétation des hautes altitudes de l'île de la Réunion (Océan Indien)

Summary The high mountains of Reunion Island (Indian ocean) harbor an ericaceous vegetation dominated byPhilippia montana. After a brief survey of the chief ecological factors, the author describes the main plant communities. Their physiognomy, floristic structure and succession have a close relation with edaphic factors.

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Zusammenfassung Das Gipfelgebiet der beiden vulkanischen Bergst?cke der Insel Reunion (Indischer Ozean) tr?gt eine Erikazeenvegetation, in welcherPhilippia montana als vorwiegende Art erscheint. Nach einer kurzen Untersuchung der bedeutendsten ?kologischen Faktoren definiert der Autor die Pflanzengesellschaften deren Physiognomie, Blütenstruktur und Entwicklung mit den edaphischen Faktoren eng zusammenh?ngen.

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Pour le nomenclature de la plupart des espèces, voir les tableaux 3 et 4.