The essential oil of the aerial parts of Baccharis tricuneata var. ruiziana (Asteraceae) from Bolivia was analyzed by GC and GC/MS. The oil is characterized by a high percentage of (E)-nerolidol (â¼68%) and the presence of several minor constituents composed mainly of monoterpenes (â¼16%), followed by sesquiterpene hydrocarbons (â¼5%) and oxygenated sesquiterpenes (â¼3%).