abstract the leaf oils of the 11 recorded western australian species of the broombush complex of the genus melaleuca have been examined by a combination of gc and gc/ms. melaleuca atroviridis produced a monoterpenic leaf oil with -pinene (11.0%) and 1,8-cineole (73.2%) being the principal components. melaleuca concreta showed the presence of three chemotypes, one of which was rich in terpinen-4-ol (35.4%), while a second was rich in 1,8-cineole (58-81%). a third chemotype contained signifcant amounts of -pinene (16.7%), 1,8-cineole (28.4%) and globulol (11.3%). melaleuca exuvia produced a monoterpenic oil, which appeared to exist in two chemotypes, which contained -pinene (13-23%), 1,8-cineole (56-67%), terpinen-4-ol (0.1-2%) and -terpineol (3-7%) in one form and -pinene (5-7%), 1,8-cineole (28-38%), terpinen-4-ol (11-17%) and -terpineol (3-4%) in the second form. melaleuca hamata produced a leaf oil that was dominated by monoterpenes. there appeared to be two chemotypes present, one in which terpinen-4-ol (41.6%) was the major component and a second chemotype in which 1,8-cineole (40.0%) and linalool (33.9%) were the principal components. melaleuca interioris (from one population) contained a mixture of mono- and sesquiterpenes, in which sesquiterpenes predominated. melaleuca osullivanii gave a leaf oil in which sesquiterpenes predominated, the principal component being spathulenol (10-18%). melaleuca scalena produced a leaf oil dominated by monoterpenes, with -pinene (25-31%) and 1,8-cineole (43-55%) being the principal components. melaleuca stereophloia was dominated by monoterpenes of which the principal component was 1,8-cineole (78-83%). melaleuca uncinata sens. strict. existed in a variety of forms one of which had major amounts of 1,8-cineole (44-56%), while a second contained major amounts of terpinen-4-ol (21-31%), -terpinene (10-14%) and -terpinene (6-8%). melaleuca vinnula appeared to exist in two chemotypes, one of which was rich in -pinene (65.3%), while the second chemotype was rich in 1,8-cineole (60.6%). melaleuca zeteticorum produced a leaf oil that was overwhelmingly monoterpene in character, the principal component being 1,8-cineole (63-68%).