abstract the chemical composition of the leaf oils of melaleuca squamophloia was studied for the first time and compared with the oil of two closely related species, m. styphelioides and m. bracteata, to help elucidate their taxonomic relationships. m. squamophloiaoccurs in two chemotypes, in which the major components of the oil are elemicin (up to 96%) or (e)-isoelemicin (up to 78%). the oil yield (w/w% fresh weight) of both chemotypes varied from 0.4% to 3-7%. m. styphelioides produced an oil in 0.05-0.1% yield in which the major compounds were the sesquiterpenes caryophyllene oxide (22-26%) and spathulenol (13-21%). m. bracteata occurs in four chemotypes distinguished by the predominance in the oil of the aromatic ethers elemicin, (e)-isoelemicin, methyl eugenol or (e)-methyl isoeugenol. oil yields in this species range from 0.2% to 0.8%. based on oil profiles, m. squamophloia appears to be a taxon distinct from m. styphelioides and unlikely to have been developed from hybridization between this species and m. bracteata, as previously suggested in the literature. m. squamophloia provides a natural source of elemicin and (e)-isoelemicin, of potential for commercial exploitation.