Researchers analyzed the volatile constituents of three Teucrium species. They used GC-FID and GC/MS analyses, identifying a total of 296 constituents that represented 89.8-98.4% of the oil compositions. The oils of two species consisted mainly of sesquiterpenes, while the third species was characterized by the monoterpene menthofuran. The study provided important chemotaxonomic information about these plants.