EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium, S. series Macaronesia (four species), S. melanantherum and S. series Rupestria (five species) of S. sect. Sedum and S. meyeri-johannis of S. sect. Africana. The waxes consist of alkanes, alkanols, fatty acids, fatty acid methyl esters, aldehydes, wax esters and triterpenes. Some 14 triterpenes were detected in waxes of Sedum, the major triterpenes being beta-amyrenyl acetate, germanicyl formate (not previously reported from a natural source), multiflorenyl acetate and taraxeryl acetate. Waxes of the pruinose and glaucous taxa of Sedum were found to have a high triterpene content. In waxes of Aeonium spathulatum and Sempervivum nevadense, no triterpenes could be detected. Variation in the alkane and triterpene profiles proved to be of significant systematic value. In general, the distribution of the triterpenes in Sedum agrees with the infrageneric classification based on hybridization patterns and related morphological characters.